Download Print this page

Komatsu WA250-6 Shop Manual

Komatsu WA250-6 Shop Manual

Wheel loader

Hide thumbs Also See for WA250-6:

Shop manual (51 pages)

,

Operation & maintenance manual (31 pages)

Table of Contents

Advertisement

Quick Links

Download this manual

WHEEL LOADER

WA250

WA250PZ

SERIAL NUMBERS

SEN03813-03

-6

-6

WA250-

75001

WA250PZ- 75001

and up

Table of Contents

Advertisement

Chapters

Table of Contents

Troubleshooting

Need help?

Need help?

Do you have a question about the WA250-6 and is the answer not in the manual?

Questions and answers

richard colbath

March 22, 2025

shift lever will not indicate nuetral, will not start

0

1 comments:

Mr. Anderson

March 22, 2025

The shift lever on a Komatsu WA250-6 may not indicate neutral and allow the machine to start due to the following reasons:

1. Directional switch is not in Neutral (N) – The system requires the FNR (directional) lever to be set in Neutral before resetting and allowing the machine to start.
2. KOMTRAX function prohibits engine start – The engine may be prevented from starting due to a restriction set by the KOMTRAX system.
3. Battery cable is not disconnected – If the battery cable is improperly connected, it may interfere with proper system operation.
4. Starting motor system or terminal C signal issue – The engine may not start because the starting motor does not run due to a fault in the starting motor system or the starting switch terminal C signal.
5. Blown fuse or grounding fault – If a fuse is blown, check the related wiring harness for grounding faults.
6. Defective battery or low voltage – The battery should have a minimum voltage of 25V and a specific gravity of at least 1.26.
7. Faulty battery relay – If the battery relay is defective, the machine may not start. A clicking sound from the relay when operating the starting switch indicates it is functioning.

These issues should be checked and resolved to ensure the shift lever indicates Neutral and allows the machine to start.

This answer is automatically generated

0

Summary of Contents for Komatsu WA250-6

Page 1 SEN03813-03 WA250 WHEEL LOADER WA250PZ WA250- 75001 SERIAL NUMBERS and up WA250PZ- 75001...
Page 2 SEN03822-03 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 00 Index and foreword 100 Index Composition of shop manual .......................... 2 Table of contents ............................. 4 WA250, 250PZ-6 00-100...
Page 3 100 Index SEN03822-03 Composition of shop manual Composition of shop manual The contents of this shop manual are shown together with Form No. in a list. Note 1: Always keep the latest version of this manual in accordance with this list and utilize accordingly. The marks shown to the right of Form No.
Page 4 100 Index SEN03822-03 Composition of shop manual 40 Troubleshooting SEN03819-01 100 Failure code table and fuse locations SEN03839-00 200 General information on troubleshooting SEN03840-01 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00...
Page 5: Table Of Contents
100 Index SEN03822-03 Table of contents Table of contents 00 Index and foreword 100 Index SEN03822-03 Composition of shop manual......................... Table of contents ............................200 Foreword and general information SEN03823-01 Safety notice ..............................How to read the shop manual ........................Explanation of terms for maintenance standard....................
Page 6 100 Index SEN03822-03 Table of contents 400 Brake system SEN03828-00 Brake piping diagram............................. Charge valve ..............................Brake valve..............................Inching valve..............................12 Accumulator (for brake) ..........................13 Slack adjuster ..............................14 Brake ................................16 Parking brake control............................. 21 Parking brake ..............................22 500 Undercarriage and frame SEN03829-00 Axle mount and center hinge pin ........................
Page 7 100 Index SEN03822-03 Table of contents 30 Testing and adjusting 110 Testing and adjusting, Part 1 SEN03836-01 Tools for testing, adjusting, and troubleshooting ................... Sketches of special tools..........................Measuring engine speed..........................10 Measuring exhaust gas color ........................12 Adjusting valve clearance ..........................14 Measuring compression pressure .........................
Page 8 100 Index SEN03822-03 Table of contents 130 Testing and adjusting, Part 3 SEN03838-00 Adjusting machine monitor ..........................Adjusting replaced, reassembled or added sensor, controller, etc. with machine monitor ......Special functions of machine monitor (EMMS)....................Pm clinic inspection chart ..........................59 40 Troubleshooting 100 Failure code table and fuse locations SEN03839-00...
Page 9 100 Index SEN03822-03 Table of contents Failure code [CA352] Sensor power supply 1 low error................52 Failure code [CA386] Sensor power supply 1 high error ................54 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA428] Abnormally high level in water sensor................ Failure code [CA429] Abnormally low level in water sensor .................
Page 10 100 Index SEN03822-03 Table of contents Failure code [DDD7KY] Travel speed control dial signal: Hot short .............. 24 Failure code [DDE5MA] Emergency steering operation switch: Disconnection ..........26 Failure code [DDK3KA] Directional selector switch: Disconnection/Hot short..........28 Failure code [DDK3KB] Directional selector switch: Ground fault ..............30 Failure code [DDK6KA] FNR lever: Disconnection/Ground fault..............
Page 11 100 Index SEN03822-03 Table of contents E-16 Alarm buzzer does not sound or it keeps sounding................68 E-17 Air conditioner does not operate or stop....................70 E-18 The KOMTRAX system does not work properly................... 73 500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 Method of using troubleshooting chart ......................
Page 12 100 Index SEN03822-03 Table of contents 50 Disassembly and assembly 100 General information on disassembly and assembly SEN03851-01 How to read this manual..........................Coating materials list ............................. Special tool list............................... Sketches of special tools ..........................11 200 Engine and cooling system SEN03852-00 Removal and installation of fuel supply pump assembly ................
Page 13 100 Index SEN03822-03 Table of contents 90 Diagrams and drawings 100 Hydraulic diagrams and drawings SEN03860-01 Hydraulic circuit diagram..........................200 Electrical diagrams and drawings SEN03861-01 Electrical circuit diagram ..........................Connector list and stereogram ........................21 00-100 WA250, 250PZ-6...
Page 14 100 Index SEN03822-03 Table of contents WA250, 250PZ-6 00-100...
Page 15 SEN03822-03 WA250-6, WA250PZ-6 Wheel loader Form No. SEN03822-03 ©2011 KOMATSU All Rights Reserved Printed in Japan 01-11 00-100...
Page 16 SEN03823-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 00 Index and foreword 200 Foreword and general information Safety notice ..............................2 How to read the shop manual ......................... 7 Explanation of terms for maintenance standard ..................... 9 Handling of electric equipment and hydraulic component ................11...
Page 17: Safety Notice
Proper service and repair are extremely important for safe machine operation. The service and repair techniques recommended by Komatsu and described in this manual are both effective and safe. Some of these techniques require the use of tools specially designed by Komatsu for the specific purpose.
Page 18 200 Foreword and general information SEN03823-01 Safety notice Preparations for work When removing a cover which is under Before adding oil or making any repairs, internal pressure or under pressure from a park the machine on a hard and level spring, always leave 2 bolts in diagonal ground, and apply the parking brake and positions.
Page 19 200 Foreword and general information SEN03823-01 Safety notice Precautions for sling work and making signs Only one appointed worker must make signs and co-workers must communicate with each other frequently. The appointed sign maker must make specified signs clearly at a place where he is well seen from the operator's seat and where he can see the working condition easily.
Page 20 200 Foreword and general information SEN03823-01 Safety notice If the load is unstable or the wire rope 13) If the hoist stops because of a power fail- or chains are twisted, lower the load ure, turn the power switch OFF. When and lift it up again.
Page 21 200 Foreword and general information SEN03823-01 Safety notice Precautions for disconnecting and con- a Example of O-ring (Fitted to every joint of necting hoses and tubes in air conditioner hoses and tubes) circuit Disconnection For the environment, the air condi- tioner of this machine uses the refrigerant (air conditioner gas: R134a) which has fewer factors of...
Page 22: How To Read The Shop Manual
This section explains the method of reproducing, repairing, and replacing parts. Revision and distribution Any additions, revisions, or other change of notices will be sent to KOMATSU distributors. Get the most up-to-date information before you start any work. WA250, 250PX-6...
Page 23 200 Foreword and general information SEN03823-01 How to read the shop manual Filing method File by the brochures in the correct order of the form number printed in the shop manual composition table. Revised edition mark When a manual is revised, the ones and tens digits of the form number of each brochure is increased by 1.
Page 24: Explanation Of Terms For Maintenance Standard
200 Foreword and general information SEN03823-01 Explanation of terms for maintenance standard Explanation of terms for maintenance standard The maintenance standard chapter explains the criteria for replacing or reusing products and parts in the machine maintenance work. The following terms are used to explain the criteria. Standard size and tolerance To be accurate, the finishing size of parts is a little different from one to another.
Page 25 200 Foreword and general information SEN03823-01 Explanation of terms for maintenance standard Standard clearance and standard value Clearance limit The clearance made when new parts are Parts can be used until the clearance assembled is called the “standard clear- between them is increased to a certain ance“, which is indicated by the range limit.
Page 26: Handling Of Electric Equipment And Hydraulic Component
200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Handling of electric equipment and hydraulic component To maintain the performance of the machine over a long period, and to prevent failures or other troubles before they occur, correct “operation“, “maintenance and inspection“, “troubleshooting“, and “repairs” must be carried out.
Page 27 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Disconnections in wiring If the wiring is held and the connectors are pulled apart, or components are lifted with a crane with the wiring still connected, or a heavy object hits the wiring, the crimping of the connector may separate, or the sol- dering may be damaged, or the wiring...
Page 28 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Removing, installing, and drying connec- tors and wiring harnesses Disconnecting connectors Hold the connectors when discon- necting. When disconnecting the connectors, hold the connectors. For connectors held by a screw, loosen the screw fully, then hold the male and female connectors in each hand and pull apart.
Page 29 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Connecting connectors Check the connector visually. Check that there is no oil, dirt, or water stuck to the connector pins (mating portion). Check that there is no deformation, defective contact, corrosion, or dam- age to the connector pins.
Page 30 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Heavy duty wire connector (DT 8-pole, 12- Disconnection Connection (Example of pole) incomplete setting of (a)) Disconnection (Left of figure) While pressing both sides of locks (a) and (b), pull out female connector (2).
Page 31 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Drying wiring harness If there is any oil or dirt on the wiring har- ness, wipe it off with a dry cloth. Avoid washing it in water or using steam. If the connector must be washed in water, do not use high-pressure water or steam directly on the wiring harness.
Page 32 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Handling controller The controller contains a microcomputer and electronic control circuits. These con- trol all of the electronic circuits on the machine, so be extremely careful when handling the controller.
Page 33 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Points to remember when handling hydraulic equipment With the increase in pressure and precision of hydraulic equipment, the most common cause of failure is dirt (foreign material) in the hydraulic circuit. When adding hydraulic oil, or when disassembling or assembling hydraulic equipment, it is necessary to be particularly careful.
Page 34 200 Foreword and general information SEN03823-01 Handling of electric equipment and hydraulic component Change hydraulic oil when the temperature is high When hydraulic oil or other oil is warm, it flows easily. In addition, the sludge can also be drained out easily from the circuit together with the oil, so it is best to change the oil when it is still warm.
Page 35: Handling Of Connectors Newly Used For Engines
200 Foreword and general information SEN03823-01 Handling of connectors newly used for engines Handling of connectors newly used for engines a Mainly, following engines are object for follow- Pull lock type (PACKARD-2) ing connectors. 95 – 170, 12V140 engines 95E-5 Various temperature sensors 107E-1 Example)
Page 36 200 Foreword and general information SEN03823-01 Handling of connectors newly used for engines Push lock type 95, 107, 114 engines Example) Fuel pressure sensor in common rail (BOSCH-03) Disconnect connector (3) according to the fol- lowing procedure. While pressing lock (C), pull out connector (3) in the direction of the arrow.
Page 37 200 Foreword and general information SEN03823-01 Handling of connectors newly used for engines 95, 125 – 170, 12V140 engines Turn-housing type (Round green connector) While pressing lock (E) of the connector, 140 engine pull out connector (5) in the direction of Example) the arrow.
Page 38: How To Read Electric Wire Code
200 Foreword and general information SEN03823-01 How to read electric wire code How to read electric wire code a The information about the wires unique to each machine model is described in Troubleshooting section, Relational information of troubleshooting. In the electric circuit diagram, the material, thickness, and color of each electric wire are indicated by sym- bols.
Page 39 200 Foreword and general information SEN03823-01 How to read electric wire code Dimensions (Table 2) Nominal No. 0.5f (0.5) 0.75f (0.85) 1.25f (1.25) Number of strands/Diam- 20/0.18 7/0.32 30/0.18 11/0.32 50/0.18 16/0.32 37/0.26 26/0.32 58/0.26 41/0.32 65/0.32 eter of strand Conductor Sectional 0.51...
Page 40 200 Foreword and general information SEN03823-01 How to read electric wire code Color codes table (Table 3) Color Code Color of wire Color Code Color of wire Black Light green & White Brown Light green & Yellow Brown & Black Blue &...
Page 41: Precautions When Carrying Out Operation
200 Foreword and general information SEN03823-01 Precautions when carrying out operation Precautions when carrying out operation [When carrying out removal or installation (disassembly or assembly) of units, be sure to follow the general precautions given below when carrying out the operation.] Precautions when carrying out removal work If the coolant contains antifreeze, dispose of it correctly.
Page 42 200 Foreword and general information SEN03823-01 Precautions when carrying out operation Precautions when carrying out installation work Tighten all bolts and nuts (sleeve nuts) to the specified (KES) torque. Install the hoses without twisting or interference and fix them with intermediate clamps, if there are any. Replace all gaskets, O-rings, cotter pins, and lock plates with new parts.
Page 43 200 Foreword and general information SEN03823-01 Precautions when carrying out operation Checking muffler and exhaust pipe for damage and looseness Visually check the muffler, exhaust pipe and their mounting parts for a crack and damage. If any part is damaged, replace it. Check the mounting bolts and nuts of the muffler, exhaust pipe and their mounting parts for looseness.
Page 44: Method Of Disassembling And Connecting Push-Pull Type Coupler
200 Foreword and general information SEN03823-01 Method of disassembling and connecting push-pull type coupler Method of disassembling and connecting push-pull type coupler Before carrying out the following work, loosen the oil filler cap of the hydraulic tank gradually to release the residual pressure from the hydraulic tank. Even if the residual pressure is released from the hydraulic tank, some hydraulic oil flows out when the hose is disconnected.
Page 45 200 Foreword and general information SEN03823-01 Method of disassembling and connecting push-pull type coupler Type 2 Disconnection Hold the tightening portion and push body (7) straight until sliding prevention ring (6) contacts contact surface (a) of the hexag- onal portion at the male end. (Fig. 6) While holding the condition of Step 1), turn lever (8) to the right (clockwise).
Page 46 200 Foreword and general information SEN03823-01 Method of disassembling and connecting push-pull type coupler Type 3 Disconnection Hold the tightening portion and push body (9) straight until sliding prevention ring (8) contacts contact surface (b) of the hexag- onal portion at the male end. (Fig. 10) While holding the condition of Step 1), push cover (10) straight until it contacts contact surface (b) of the hexagonal por-...
Page 47: Standard Tightening Torque Table
200 Foreword and general information SEN03823-01 Standard tightening torque table Standard tightening torque table Table of tightening torques for bolts and nuts a Unless there are special instructions, tighten metric nuts and bolts to the torque below. a The following table applies to the bolts in Fig. A. Thread diameter of bolt Width across flats Tightening torque...
Page 48 200 Foreword and general information SEN03823-01 Standard tightening torque table Table of tightening torques for split flange bolts a Unless there are special instructions, tighten split flange bolts to the torque below. Thread diameter of bolt Width across flats Tightening torque 59 –...
Page 49 200 Foreword and general information SEN03823-01 Standard tightening torque table Table of tightening torques for hoses (taper seal type and face seal type) a Unless there are special instructions, tighten the hoses (taper seal type and face seal type) to the torque below.
Page 50 200 Foreword and general information SEN03823-01 Standard tightening torque table Table of tightening torques for 102, 107 and 114 engine series (Eye joints) a Unless there are special instructions, tighten the metric eye joints of the 102, 107 and 114 engine series to the torque below.
Page 51: Conversion Table
200 Foreword and general information SEN03823-01 Conversion table Conversion table Method of using the conversion table The conversion table in this section is provided to enable simple conversion of figures. For details of the method of using the conversion table, see the example given below. Example: Method of using the conversion table to convert from millimeters to inches Convert 55 mm into inches.
Page 52 200 Foreword and general information SEN03823-01 Conversion table Millimeters to inches 1 mm = 0.03937 in 0.039 0.079 0.118 0.157 0.197 0.236 0.276 0.315 0.354 0.394 0.433 0.472 0.512 0.551 0.591 0.630 0.669 0.709 0.748 0.787 0.827 0.866 0.906 0.945 0.984 1.024 1.063...
Page 53 200 Foreword and general information SEN03823-01 Conversion table Liters to U.K. Gallons 1 l = 0.21997 U.K.Gal 0.220 0.440 0.660 0.880 1.100 1.320 1.540 1.760 1.980 2.200 2.420 2.640 2.860 3.080 3.300 3.520 3.740 3.950 4.179 4.399 4.619 4.839 5.059 5.279 5.499 5.719...
Page 54 200 Foreword and general information SEN03823-01 Conversion table kg/cm to lb/in 1 kg/cm = 14.2233 lb/in 14.2 28.4 42.7 56.9 71.1 85.3 99.6 113.8 128.0 142.2 156.5 170.7 184.9 199.1 213.4 227.6 241.8 256.0 270.2 284.5 298.7 312.9 327.1 341.4 355.6 369.8 384.0...
Page 55 200 Foreword and general information SEN03823-01 Conversion table Temperature Fahrenheit-Centigrade conversion: A simple way to convert a Fahrenheit temperature reading into a Centi- grade temperature reading or vice versa is to enter the accompanying table in the center (boldface column) of figures.
Page 56 200 Foreword and general information SEN03823-01 Conversion table WA250, 250PX-6 00-200...
Page 57 SEN03823-01 WA250-6, WA250PZ-6 Wheel loader Form No. SEN03823-01 ©2009 KOMATSU All Rights Reserved Printed in Japan 06-09 00-200...
Page 58: 01 Specification
SEN03824-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 01 Specification 100 Specification and technical data Specification dimension drawing........................3 Specifications ..............................4 Weight table ..............................8 Table of fuel, coolant and lubricants......................10...
Page 59: 100 Specification And Technical Data
100 Specification and technical data SEN03824-00 01-100 WA250, 250PZ-6...
Page 60: Specification Dimension Drawing
Normal load kN {kg} 36.1 {3,680} 34.5{3,520} Bucket capacity (heaped, with BOC) Engine model — Komatsu SAA6D107E-1 Diesel engine Engine rated output • Net [ISO 9249/SAE J1349] (*1) kW{HP}/rpm 103 {138}/2,000 • Gross [SAE J1955] (*2) 104.1 {140}/2,000 A Overall length (with BOC)
Page 61: Specifications
100 Specification and technical data SEN03824-00 Specifications Specifications Machine model name WA250-6 WA250PZ-6 Serial No. 75001 and up 75001 and up Machine weight 11,520 12,725 Machine weight (front wheel) in 4,485 5,670 SAE travel posture Machine weight (rear wheel) in...
Page 62 100 Specification and technical data SEN03824-00 Specifications Machine model name WA250-6 WA250PZ-6 Serial No. 75001 and up 75001 and up Model SAA6D107E-1 4-cycle, water-cooled, in-line 6-cylinder, direct injection type Type with turbocharger and air-cooled aftercooler Cylinder bore x Cylinder stroke...
Page 63 100 Specification and technical data SEN03824-00 Specifications Machine model name WA250-6 WA250PZ-6 Serial No. 75001 and up 75001 and up Braking method 4-wheel brake, independent front and rear wheel brakes Type of brake Enclosed wet multiple disc type Drive method...
Page 64 100 Specification and technical data SEN03824-00 Specifications Machine model name WA250-6 WA250PZ-6 Serial No. 75001 and up 75001 and up Type — Double-acting piston type Cylinder bore — Piston rod outside diameter — Stroke — Max. distance between — centers of pins Min.
Page 65: Weight Table
SEN03824-00 Weight table Weight table This weight table is prepared for your reference when handling or transporting the components. Unit: kg Machine model name WA250-6 WA250PZ-6 Serial No. 75001 and up 75001 and up Engine (excluding coolant and oil) Damper Cooling assembly (excluding coolant and oil) •...
Page 66 100 Specification and technical data SEN03824-00 Weight table Unit: kg Machine model name WA250-6 WA250PZ-6 Serial No. 75001 and up 75001 and up Lift arm (including bushing) Bucket link Bell crank Bucket (including BOC) • 2.3 m — • 2.2 m —...
Page 67: Table Of Fuel, Coolant And Lubricants
100 Specification and technical data SEN03824-00 Table of fuel, coolant and lubricants Table of fuel, coolant and lubricants a For details of notes (Notes 1 and 2…) in the table, see "Operation and Maintenance Manual". Unit: l Reservoir Specified capacity Refill capacity Engine oil pan 25.5...
Page 68: Table Of Fuel, Coolant And Lubricants
100 Specification and technical data SEN03824-00 Table of fuel, coolant and lubricants WA250, 250PZ-6 01-100...
Page 69 SEN03824-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03824-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 01-100...
Page 70: Structure, Function And Maintenance Standard
SEN03825-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 100 Engine and cooling system Engine mount and transfer mount........................2 Damper ................................3 Cooling system ............................... 4 Cooling system hydraulic piping diagram .......................
Page 71: Engine Mount And Transfer Mount
100 Engine and cooling system SEN03825-00 Engine mount and transfer mount Engine mount and transfer mount 10-100 WA250, 250PZ-6...
Page 72: Damper
100 Engine and cooling system SEN03825-00 Damper Damper Unit: mm Check item Criteria Remedy Standard size Repair limit Distance between HST pump Adjust installation surface and boss tip 75.1 ±0.8 Wear on internal teeth of coupling Repair limit: 1.0 Replace (resin) 3.
Page 73: Cooling System
100 Engine and cooling system SEN03825-00 Cooling system Cooling system 1. Reservoir tank 5. Aftercooler 2. Oil cooler 6. Transfer oil cooler 3. Radiator cap 7. Cooling fan 4. Radiator 8. Cooling fan motor Specifications Radiator Oil cooler Aftercooler Core type AL WAVE-4 CF40-1 AL WAVE...
Page 74: Cooling System Hydraulic Piping Diagram
100 Engine and cooling system SEN03825-00 Cooling system hydraulic piping diagram Cooling system hydraulic piping diagram 1. Cooling fan motor Outline 2. Strainer Cooling fan motor (1) installed in the machine 3. Hydraulic tank rear side is driven by oil pressure from brake 4.
Page 75 100 Engine and cooling system SEN03825-00 Cooling system hydraulic piping diagram 10-100 WA250, 250PZ-6...
Page 76: Cooling Fan Motor
100 Engine and cooling system SEN03825-00 Cooling fan motor Cooling fan motor Type: LMF16 P: From pump through charge valve Specifications T: To hydraulic tank through return filter Type: LMF16 TC: To hydraulic tank Capacity: 11.5 cm /rev Rated speed: 1,700 rpm 1.
Page 77 100 Engine and cooling system SEN03825-00 Cooling fan motor 10-100 WA250, 250PZ-6...
Page 78 100 Engine and cooling system SEN03825-00 Cooling fan motor 1. Output shaft 2. Case 3. Thrust plate 4. Shoe 5. Piston 6. Cylinder block 7. Valve plate 8. End cover 9. Bearing 10. Center spring 11. Retainer shoe 12. Retainer guide 13.
Page 79 100 Engine and cooling system SEN03825-00 Cooling fan motor 1. Hydraulic motor Function This hydraulic motor is called a swash plate- type axial piston motor. It converts the energy of the pressurized oil sent from the hydraulic pump into rotary motion. Principle of operation The pressurized oil from the hydraulic pump flows through valve plate (7) into cylinder block...
Page 80 100 Engine and cooling system SEN03825-00 Cooling fan motor 2. Suction safety valve 1) Suction function (2) When the pump is stopped When the engine stops, the input revolution of Function the pump becomes 0 rpm. If the fan pump stops, the pressurized oil does The pressurized oil from the pump is not sup- not flow into the motor.
Page 81 100 Engine and cooling system SEN03825-00 Cooling fan motor 2) Safety function Function When the engine is started, the pressure in port (P) of the fan motor is heightened in some cases. Suction safety valve (1) is installed to protect the fan system circuit.
Page 82 100 Engine and cooling system SEN03825-00 Cooling fan motor 3. Operation of reversible valve 1) When the ON/OFF solenoid is 2) When the ON/OFF solenoid is energized de-energized When ON/OFF solenoid (1) is "energized", When ON/OFF solenoid (1) is "de-energized", valve (2) is switched.
Page 83 100 Engine and cooling system SEN03825-00 Cooling fan motor 4. Flow control valve (continuously-variable type) Function This valve supplies the necessary pump delivery to the motor, and returns the excessive oil to the hydraulic tank. The motor speed increases in proportion to the increase of the incoming oil (Q) as shown in Fig.
Page 84 100 Engine and cooling system SEN03825-00 Cooling fan motor WA250, 250PZ-6 10-100...
Page 85 SEN03825-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03825-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-100...
Page 86 SEN03826-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 200 Power train Power train..............................3 Power train system diagram ........................... 4 Drive shaft............................... 6 HST hydraulic piping diagram......................... 7 HST pump...............................
Page 87: 200 Power Train
200 Power train SEN03826-00 10-200 WA250, 250PZ-6...
Page 88: Power Train
200 Power train SEN03826-00 Power train Power train 1. Engine 2. Damper 3. HST pump 4. 4-gear pump 5. High-pressure hose 6. HST motor 1 7. HST motor 2 8. Transfer 9. Front drive shaft 10. Front axle 11. Rear drive shaft 12.
Page 89: Power Train System Diagram
200 Power train SEN03826-00 Power train system diagram Power train system diagram 10-200 WA250, 250PZ-6...
Page 90 200 Power train SEN03826-00 Power train system diagram 1. Engine Outline 2. Damper The power from engine (1) is transmitted to 3. HST pump HST pump (3) after its torsional vibrations have 4. Steering pump been reduced with damper (2) installed on the 5.
Page 91: Drive Shaft
200 Power train SEN03826-00 Drive shaft Drive shaft 1. Front axle Outline 2. Front drive shaft The power from the transfer output shaft is 3. Transfer transmitted to front axle (1) and rear axle (5) 4. Rear drive shaft through front drive shaft (2) and rear drive 5.
Page 92: Hst Hydraulic Piping Diagram
200 Power train SEN03826-00 HST hydraulic piping diagram HST hydraulic piping diagram 1. Hydraulic tank 2. HST pump 3. HST drain oil filter 4. Clutch solenoid valve 5. HST oil filter 6. HST motor 1 7. HST motor 2 WA250, 250PZ-6 10-200...
Page 93: Hst Pump
200 Power train SEN03826-00 HST pump HST pump a HST: Abbreviation for HydroStatic Transmission 1. Directional selector solenoid valve Specifications 2. High-pressure cutoff valve Model name A4VG90DA 3. Speed-related valve (DA valve) Variable displacement 4. Charge pump Type swash plate type piston 5.
Page 94 200 Power train SEN03826-00 HST pump Operation Flow of power Flow of oil The HST pump is installed on the damper of Inclination of swash plate (11) starts reciprocat- the engine flywheel. ing movement of piston (10). The pumping The power from the engine is transmitted to action initiated by this reciprocating movement the HST pump through the flywheel and suctions or discharges the oil in cylinder block...
Page 95 200 Power train SEN03826-00 HST pump High-pressure relief valve 1. Nut Function 2. Locknut This valve is installed on the HST pump. If the 3. Poppet spring oil pressure on the high pressure circuit side 4. Check spring across the HST pump and HST motor goes 5.
Page 96 200 Power train SEN03826-00 HST pump Operation Port (A) is connected to the high pressure cir- As the oil pressure in chamber (B) goes lower, cuit side of the HST pump, and ports (C) and the orifice of main piston (5) is activated and (D) are connected to the low pressure circuit differential pressure is generated in port (A) side of the pump.
Page 97 200 Power train SEN03826-00 HST pump Low-pressure relief valve When increasing the set pressure, loosen lock- nut (1) and screw adjustment screw (2). When decreasing, loosen the adjustment screw. 1. Locknut 2. Adjustment screw 3. Piston 4. Spring Function This valve is installed on the HST pump. If the oil pressure on the low pressure circuit side across the HST pump and HST motor goes beyond the set pressure, it drains the oil to the...
Page 98 200 Power train SEN03826-00 HST pump HST charge pump 1. Cover bolt Specifications 2. Pump gear Gear pump Type 3. Key (inscription type) 4. Coupling Theoretical delivery 19.6 5. Drive shaft (cc/rev) 6. Plate 7. Charge pump cover Function 8. Crescent separator plate This pump is connected to the HST pump drive Outline shaft (5) with coupling (4).
Page 99 200 Power train SEN03826-00 HST pump Speed-related valve (DA valve) 1. Locknut 2. Adjustment screw 3. Poppet spring 4. Spring seat 5. Pilot poppet Function It diverges the oil from the HST charge pump into 2 parts. One part flows to the directional selector solenoid valve and other part flows to the low-pressure relief valve.
Page 100 200 Power train SEN03826-00 HST pump High-pressure cutoff valve 1. Adjustment screw 2. Locknut 3. Spring 4. Spool 5. Piston 6. Barrel 7. Shuttle spool 8. Valve seat Function This valve is installed on the HST pump. If the oil pressure on the high pressure circuit side across the HST pump and HST motor goes beyond the set pressure, it drains the oil in the servo cylinder circuit to the hydraulic tank.
Page 101: Hst Motor
200 Power train SEN03826-00 HST motor HST motor a HST: Abbreviation for HydroStatic Transmission HST motor 1 1. Drive shaft Specifications 2. Piston Model name A6VM107EP 3. Cylinder block Variable displacement bent Type 4. Port plate axis type piston motor 5.
Page 102 200 Power train SEN03826-00 HST motor HST motor 2 1. Drive shaft Specifications 2. Piston Model name A6VM107HA 3. Cylinder block Variable displacement bent 4. Port plate Type axis type piston motor 5. HA servo valve Theoretical delivery 6. Directional shuttle valve –...
Page 103 200 Power train SEN03826-00 HST motor Principle Operation It is assumed that the shaft of the disc is sup- Pressurized oil from the HST pump flows to the ported to enable free rotation of the disc. Force back side of piston (2) through the HST motor F being applied aslant to the disc is divided inlet port, and is activated by inclination of pis- into force F1 orthogonal to the disc and force...
Page 104 200 Power train SEN03826-00 HST motor EP servo valve 1. Motor 1 solenoid valve Operation 2. EP servo valve Suction force F1 of motor 1 solenoid valve (1) 3. Spring and force F2 of spring (3) are applied to EP 4.
Page 105 200 Power train SEN03826-00 HST motor HA servo valve 1. Motor 2 solenoid valve Operation 2. HA servo valve If the load to the motor is small, HA servo valve 3. Servo cylinder (2) conducts oil pressure to the small diameter side (S) through the directional shuttle valve Function and releases the oil pressure on the large...
Page 106 200 Power train SEN03826-00 HST motor Directional shuttle valve 1. Directional selector solenoid valve 2. Directional shuttle valve Function This valve is installed in the rear side of HST motor 2. It controls the destination of the oil pressure to work on the HA servo valve refer- encing the incoming signal, which corresponds to the directional signal of the directional selec- tor solenoid valve on the HST pump.
Page 107: Transfer
200 Power train SEN03826-00 Transfer Transfer a: Clutch port b: Lubrication inlet port c: Lubrication suction port 1. HST motor 2 mounting section 2. HST motor 1 mounting section 3. Oil filler pipe 4. Transfer 5. Parking brake lever 6. Speed sensor 10-200 WA250, 250PZ-6...
Page 108 200 Power train SEN03826-00 Transfer 1. HST motor 1 9. Sun gear (number of teeth: 28) 2. Input shaft 10. Parking brake 3. Transfer clutch 11. Rear coupling 4. Carrier 12. Output gear (number of teeth: 57) 5. Ring gear (number of teeth: 80) 13.
Page 109 200 Power train SEN03826-00 Transfer Input shaft Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between input shaft and Shaft Hole bearing (front) +0.011 –0.023 – — –0.005 –0.012 0.005 Clearance between input shaft +0.013 –0.006 –...
Page 110 200 Power train SEN03826-00 Transfer Unit: mm Check item Criteria Remedy Standard size Tolerance Repair limit Thickness of separator plate ±0.05 Strain on separator plate — 0.05 0.15 Thickness of friction plate ±0.08 Strain on friction plate — 0.02 0.25 Load of wave spring 1,010 N ±101 N...
Page 111 200 Power train SEN03826-00 Transfer Output shaft 10-200 WA250, 250PZ-6...
Page 112 200 Power train SEN03826-00 Transfer Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Shaft Hole Clearance between output shaft and bearing (front) +0.030 –0.045 – — +0.011 –0.015 –0.011 Clearance between output shaft –0.015 –0.040 – —...
Page 113 200 Power train SEN03826-00 Transfer 10-200 WA250, 250PZ-6...
Page 114 200 Power train SEN03826-00 Transfer 1. HST motor 2 2. Motor 2 gear (number of teeth: 44) 3. Strainer 4. Drain plug Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between input shaft and Shaft Hole bearing...
Page 115 200 Power train SEN03826-00 Transfer Outline Operation of clutch The transfer is equipped with 2 HST motors. It selects a gear speed out of 1st - 4th speed Clutch is "engaged" (fixed) both in the forward and reverse travels and transmits it to the output shaft.
Page 116 200 Power train SEN03826-00 Transfer Power transmitting route Low speed mode Transfer clutch (1) is fixed to transmit power of both HST motor 1 (2) and HST motor 2 (3). Power of HST motor 1 (2) Power of HST motor 2 (3) Input shaft (4) Sun gear (5) Planetary pinion (6)
Page 117 200 Power train SEN03826-00 Transfer High speed mode Transfer clutch (1) is released and, since HST motor 1 (2) stops, it transmits power of HST motor 2 (3) alone. Power of HST motor 2 (3) Motor 2 gear (9) Output gear (10) Output shaft (11) 10-200 WA250, 250PZ-6...
Page 118: Clutch Solenoid Valve
200 Power train SEN03826-00 Clutch solenoid valve Clutch solenoid valve P: From HST charge pump Operation A: To transfer clutch When the current value of input signal is large, T: To drain the transfer clutch drains oil pressure. As the current value of input signal becomes 1.
Page 119: Axle
200 Power train SEN03826-00 Axle Axle Front axle 1. Differential 2. Final drive 3. Axle shaft 4. Axle housing 5. Wet multiple disc type brake 6. Coupling 7. Oil filler port and level plug 8. Drain plug 9. Brake oil port 10.
Page 120 200 Power train SEN03826-00 Axle Rear axle 1. Differential 2. Final drive 3. Axle shaft 4. Axle housing 5. Wet multiple disc type brake 6. Coupling 7. Oil filler port and level plug 8. Drain plug 9. Brake oil port 10.
Page 121: Differential
200 Power train SEN03826-00 Differential Differential Front differential 1. Pinion (number of teeth: 9) 2. Shaft 3. Bevel gear (number of teeth: 43) 4. Sun gear shaft 5. Bevel pinion (number of teeth: 12) 6. Side gear (number of teeth: 12) 10-200 WA250, 250PZ-6...
Page 122 200 Power train SEN03826-00 Differential Unit: mm Check item Criteria Remedy Starting torque of bevel gear 88.2 – 205.8 Nm {0.9 – 2.1 kgm} (outside of bevel gear) Adjust Standard size Tolerance Repair limit Thickness of pinion washer ±0.08 Replace Thickness of side gear washer ±0.05 Thickness of shim in differential...
Page 123 200 Power train SEN03826-00 Differential Rear differential 1. Pinion (number of teeth: 9) 2. Shaft 3. Bevel gear (number of teeth: 43) 4. Sun gear shaft 5. Bevel pinion (number of teeth: 12) 6. Side gear (number of teeth: 12) 10-200 WA250, 250PZ-6...
Page 124 200 Power train SEN03826-00 Differential Unit: mm Check item Criteria Remedy Starting torque of bevel gear 88.2 – 205.8 Nm {0.9 – 2.1 kgm} (outside of bevel gear) Adjust Standard size Tolerance Repair limit Thickness of pinion washer ±0.08 Replace Thickness of side gear washer ±0.05 Thickness of shim in differential...
Page 125 200 Power train SEN03826-00 Differential Outline While machine is traveling straight The power from the engine is transmitted to the front and rear axles through the torque converter, transmission and drive shaft. While the machine is traveling straight, the In each axle, the direction of the power is right and left wheels rotate at the same speed.
Page 126: Torque Proportioning Differential
200 Power train SEN03826-00 Torque proportioning differential Torque proportioning differential Outline Operation Straight travel (When the road resistances under both tires are the same) When the road resistances under the both tires are the same, distance (a) from pinion (4) to the meshing point of left side gear (7) and dis- tance (b) to the meshing point of right side gear (3) are the same.
Page 127 200 Power train SEN03826-00 Torque proportioning differential Accordingly, the pinion does not run idle and the drive force is transmitted to both side gears and the tires do not slip until the ratio of (a) : (b) becomes 1 : 1.38, or the difference between the road resistances under both tires becomes 38%.
Page 128 200 Power train SEN03826-00 Torque proportioning differential WA250, 250PZ-6 10-200...
Page 129: Limited Slip Differential
200 Power train SEN03826-00 Limited slip differential Limited slip differential (if equipped) 1. Plate 2. Disc 3. Pinion (number of teeth: 12) 4. Washer 5. Side gear (number of teeth: 24) 6. Bevel pinion 7. Shaft 8. Pressure ring 9. Bevel gear (number of teeth: 43) 10.
Page 130 200 Power train SEN03826-00 Limited slip differential Unit: mm Check item Criteria Remedy Standard size Tolerance Repair limit Thickness of plate ±0.02 +0.04 Thickness of disc 2.45 –0.03 Thicknesses of washer ±0.05 Clearance between disc and plate 0.2 – 0.6 (total clearance on both sides) Replace End play of side gear in axial...
Page 131 200 Power train SEN03826-00 Limited slip differential Operation of limited slip differential While machine is traveling straight The power from the transmission is transmitted When the drive forces of the right and left through bevel gear (9), case (10), pressure wheels are balanced ring (8), shaft (7), pinion (3) and side gear (5), [When the road conditions (coefficient of friction)
Page 132 200 Power train SEN03826-00 Limited slip differential When the drive forces of the right and left Difference in wheel drive force by type of differ- wheels are unbalanced entials when either wheel slipped [When the road conditions (coefficient of friction) Wheel drive force (drive force of slipping wheel is 1) under both wheels and the wheel loads are uneven,...
Page 133: Final Drive
200 Power train SEN03826-00 Final drive Final drive Front final drive 1. Planetary gear (number of teeth: 26) 2. Planetary carrier 3. Axle shaft 4. Ring gear (number of teeth: 69) 5. Sun gear shaft (number of teeth: 15) 10-200 WA250, 250PZ-6...
Page 134 200 Power train SEN03826-00 Final drive Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Shaft Hole Clearance between planetary gear bearing and shaft +0.025 +0.013 –0.025 – Replace 33.338 — +0.013 Clearance between axle housing +0.100 +0.100 –0.100 –...
Page 135 200 Power train SEN03826-00 Final drive Rear final drive 1. Planetary gear (number of teeth: 26) 2. Planetary carrier 3. Axle shaft 4. Ring gear (number of teeth: 69) 5. Sun gear shaft (number of teeth: 15) 10-200 WA250, 250PZ-6...
Page 136 200 Power train SEN03826-00 Final drive Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Shaft Hole Clearance between planetary gear bearing and shaft +0.025 +0.013 –0.025 – Replace 33.338 — +0.013 Clearance between axle housing +0.100 +0.100 –0.100 –...
Page 137 200 Power train SEN03826-00 Final drive Outline The final drive finally reduces speed of the power from the engine to increase the drive force. Ring gear (4) is press fitted to the axle housing and fixed with the pin. Speed of the power being transmitted from the differential through sun gear shaft (5) is reduced by the planetary gear unit to increase the drive force.
Page 138 200 Power train SEN03826-00 Final drive WA250, 250PZ-6 10-200...
Page 139 SEN03826-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03826-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-200...
Page 140 SEN03827-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 300 Steering system Steering piping diagram ..........................3 Steering column .............................. 4 Priority valve ..............................5 Orbit-roll valve..............................8 2-way restrictor valve ............................
Page 141 300 Steering system SEN03827-01 10-300 WA250, 250PZ-6...
Page 142: Steering Piping Diagram
300 Steering system SEN03827-01 Steering piping diagram Steering piping diagram 1. Steering cylinder (right) 2. Orbit-roll valve 3. Hydraulic tank 4. Priority valve 5. Steering pump 6. 2-way restrictor valve 7. Cushion valve 8. Steering cylinder (left) WA250, 250PZ-6 10-300...
Page 143: Steering Column
300 Steering system SEN03827-01 Steering column Steering column 1. Steering wheel 2. Steering column 3. Orbit-roll valve 4. Steering tilt lock lever Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between steering shaft Shaft Hole Replace and column bushing...
Page 144: Priority Valve
300 Steering system SEN03827-01 Priority valve Priority valve P: From steering pump LS: From Orbit-roll valve CF: To Orbit-roll valve T: To hydraulic tank EF: To work equipment control valve 1. Relief valve body 7. Plug 2. Spring seat 8. Valve body 3.
Page 145 300 Steering system SEN03827-01 Priority valve Outline Operation The priority valve is installed between the steering pump and Orbit-roll valve and work When steering wheel is at "neutral" position equipment control valve. It diverges the oil from the steering pump to the steering circuit or work equipment circuit.
Page 146 300 Steering system SEN03827-01 Priority valve When steering wheel is "turned left" When steering cylinder is at stroke end Turning the steering wheel left changes the Trying to continuously turn the steering wheel angle between the sleeve and spool on the after the steering cylinder has reached the Orbit-roll valve, switching flow of the oil.
Page 147: Orbit-Roll Valve
300 Steering system SEN03827-01 Orbit-roll valve Orbit-roll valve P: From steering pump LS: To priority valve L: To steering cylinder T: To hydraulic tank R: To steering cylinder 1. Gland 8. Drive shaft 2. Valve body 9. Sleeve 3. Check valve 10.
Page 148 300 Steering system SEN03827-01 Orbit-roll valve Outline Structure The Orbit-roll valve is connected to the drive Top (A) of spool (9) is connected to the drive shaft of the steering column. It changes the oil shaft of the steering column and further con- flow from the steering pump to the right or left nected to sleeve (8) through center pin (7) steering cylinder to decide the travel direction...
Page 149 300 Steering system SEN03827-01 Orbit-roll valve Operation When steering wheel is at "neutral" position 10-300 WA250, 250PZ-6...
Page 150 300 Steering system SEN03827-01 Orbit-roll valve When the steering wheel is at "neutral" posi- tion, centering spring (2) sets center pin (7) to the center of the oblong hole on spool (9) and move of spool (9) and sleeve (8) is stopped. Port (A) from sleeve (8) pump, port (E) to the Gerotor, port (F) to the R.H.
Page 151 300 Steering system SEN03827-01 Orbit-roll valve When steering wheel is "turned left" 10-300 WA250, 250PZ-6...
Page 152 300 Steering system SEN03827-01 Orbit-roll valve When steering wheel is at "stop" position As the steering wheel is "turned left", spool (9) As operation of the steering wheel is stopped, being connected to the drive shaft of the steer- angular displacement between spool (9) and ing column is rotated counterclockwise.
Page 153 300 Steering system SEN03827-01 Orbit-roll valve Connection of hand pump and sleeve Above figure shows the suction and discharge As shown above, the ports in the discharge ports (P) of the Gerotor and connections with state of the Gerotor are connected to the ports the sleeve ports.
Page 154 300 Steering system SEN03827-01 Orbit-roll valve Role of centering spring Centering spring (2) is composed of 4 X- shaped leaf springs and 2 flat leaf springs and installed between spool (9) and sleeve (8) as shown in the figure. If the steering wheel is turned, spool (9) com- presses centering spring (2) and angular dis- placement (a) is generated between spool (9) and sleeve (8).
Page 155: 2-Way Restrictor Valve
300 Steering system SEN03827-01 2-way restrictor valve 2-way restrictor valve 1. Tube 2. Poppet 3. Body Function In order to buffer the impacts resulting from the momentum of the machine when switching the steering, an orifice installed in the circuit near to the cylinder controls the move of the cylinder piston by giving pressure to the return oil.
Page 156: Cushion Valve
300 Steering system SEN03827-01 Cushion valve Cushion valve A: From steering cylinder left turning port Outline B: From steering cylinder right turning port If sudden increase or bouncing occurs in oil pressure of the steering cylinder circuit, this 1. Valve seat valve mitigates the impacts by releasing the 2.
Page 157: Steering Cylinder
300 Steering system SEN03827-01 Steering cylinder Steering cylinder Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance Clearance between bushing in size clearance limit Shaft Hole cylinder rod frame connecting part +0.180 0.042 – and mounting pin — –0.025 +0.042 0.205 Clearance between bushing in...
Page 158 300 Steering system SEN03827-01 Steering cylinder Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between piston rod and Shaft Hole bushing –0.025 +0.132 0.031 – 0.519 –0.087 +0.006 0.219 Replace pin and bushing Clearance between piston rod +0.180 0.042 –...
Page 159: Emergency Steering Piping Diagram
300 Steering system SEN03827-01 Emergency steering piping diagram Emergency steering piping diagram (if equipped) 1. Steering pump 2. Priority valve 3. Orbit-roll valve 4. Check valve 5. Emergency steering valve 6. HST motor 2 7. Pressure switch (for detecting emergency steering operation) 8.
Page 160: Emergency Steering Valve
300 Steering system SEN03827-01 Emergency steering valve Emergency steering valve (if equipped) PP: From steering pump 1. Check valve body A: To HST motor 2 port A 2. Check valve B: To HST motor 2 port B 3. Valve body Y: To Orbit-roll valve 4.
Page 161 300 Steering system SEN03827-01 Emergency steering valve Operation When engine and steering pump are normal As long as the engine and steering pump are operating normally, the oil being pressure-fed from the steering pump flows to the Orbit-roll valve, enabling the steering. The oil from the steering pump flows to port (PP), pushes spool (1) in the left direction, then cuts off the circuit from the HST motor to the...
Page 162 300 Steering system SEN03827-01 Emergency steering valve When engine or steering pump is abnormal If, during travel, the steering pump fails to sup- ply sufficient amount of oil to the Orbit-roll valve due to a trouble on the engine or steering pump, discharge pressure of the steering pump goes low.
Page 163: Steering Relief Valve
300 Steering system SEN03827-01 Steering relief valve Steering relief valve (if equipped) P1: From steering pump Outline P2: From emergency steering pump The steering relief valve is installed to the right T: Drain side of the transmission and used to hold the S1: Steering pump oil pressure switch (Low) steering oil pressure to the set pressure.
Page 164 300 Steering system SEN03827-01 Steering relief valve WA250, 250PZ-6 10-300...
Page 165 SEN03827-01 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03827-01 ©2007 KOMATSU All Rights Reserved Printed in Japan 10-07 (01) 10-300...
Page 166 SEN03828-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 400 Brake system Brake piping diagram ............................3 Charge valve ..............................4 Brake valve ..............................8 Inching valve ..............................12 Accumulator (for brake) ..........................
Page 167 400 Brake system SEN03828-00 10-400 WA250, 250PZ-6...
Page 168: Brake Piping Diagram
400 Brake system SEN03828-00 Brake piping diagram Brake piping diagram 1. Hydraulic tank 8. Strainer 2. Brake valve 9. Slack adjuster (for front left side) 3. Brake and cooling fan pump 10. Front brake 4. Rear brake 11. Slack adjuster (for front right side) 5.
Page 169: Charge Valve
400 Brake system SEN03828-00 Charge valve Charge valve 10-400 WA250, 250PZ-6...
Page 170 400 Brake system SEN03828-00 Charge valve P: From brake and cooling fan pump T: To hydraulic tank A: To cooling fan motor ACC1: To accumulator (rear side) ACC2: To accumulator (front side) S: Brake operation sensor port G: Gauge port 1.
Page 171 400 Brake system SEN03828-00 Charge valve Operation When oil is not supplied to accumulator When oil is supplied to accumulator (cut-out state) Cut-in state Plunger (1) is moved in the left direction by the As the accumulator pressure goes low, pres- accumulator pressure, and maintains unload sure on port (E) goes low, allowing plunger (1) relief valve (2) being pushed open.
Page 172 400 Brake system SEN03828-00 Charge valve When the oil pressure from the pump went When pressure reaches cut-out pressure beyond the set pressure As pressure in port (F) reaches the set pres- As oil pressure in chamber (B) reaches the set sure (cut-out pressure of unload relief valve pressure of relief valve (6), relief valve (6) is (2)), oil in the spring chamber of unload valve...
Page 173: Brake Valve
400 Brake system SEN03828-00 Brake valve Brake valve P1: From HST pump A: To Rear brake T1: To hydraulic tank PB: From accumulator (front side) T2: To steering pump (suction side) B: To front brake PA: From accumulator (rear side) 1.
Page 174 400 Brake system SEN03828-00 Brake valve Outline The brake valve is installed in the lower front side of the operator's seat. Pressing the brake pedal conducts oil to the brake piston, operat- ing the brake. The left side and right side brake pedals are mechanically interlocked.
Page 175 400 Brake system SEN03828-00 Brake valve Balancing operation As the rear brake piston is filled with oil and the oil pressure rises between port (PA) and port (A), the oil being conducted to chamber (E) through orifice (c) of spool (5) pushes spool (5) in the left direction resisting repulsive force of spring (4).
Page 176 400 Brake system SEN03828-00 Brake valve When brake pedal is released Releasing brake pedal (1) releases the pedal pressing effort being applied to spool (5). Spool (5) is pushed back in the left direction by the back pressure of the rear brake piston and repulsive force of spring (7), and port (PA) and port (A) are closed.
Page 177: Inching Valve
400 Brake system SEN03828-00 Inching valve Inching valve P1: From HST pump port Y Outline T2: To steering pump (suction side) The inching valve, which is contained in brake valve (2), reduces the control oil pressure of 1. Brake pedal the HST circuit responding to stroke (S) of 2.
Page 178: Accumulator (For Brake)
400 Brake system SEN03828-00 Accumulator (for brake) Accumulator (for brake) 1. Cylinder 2. Free piston Function The accumulator is installed between the charge valve and brake valve. The space between cylinder (1) and free piston (2) is filled with nitrogen gas. The nitrogen gas absorbs the hydraulic pulses generated by the hydrau- lic pump and secures the braking force and operability when the engine is stopped by uti-...
Page 179: Slack Adjuster
400 Brake system SEN03828-00 Slack adjuster Slack adjuster A: From brake valve B: To brake piston 1. Body 2. Check valve 3. Piston Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between piston and Shaft Hole body...
Page 180 400 Brake system SEN03828-00 Slack adjuster Function The slack adjuster is installed between the brake valve and brake piston. It maintains the time lag up to activation of the brake constant. Operation When brake is applied When brake is released The oil from the brake valve flows to port (A) The oil being stopped between piston (1) and and moves piston (1) in the right direction to...
Page 181: Brake
400 Brake system SEN03828-00 Brake Brake Front brake 1. Differential housing 2. Bearing carrier 3. Piston 4. Spring 5. Inner ring 6. Sun gear shaft 7. Axle housing 8. Outer ring 9. Disc (2 pieces) 10-400 WA250, 250PZ-6...
Page 182 400 Brake system SEN03828-00 Brake Unit: mm Check item Criteria Remedy Standard size Tolerance Repair limit Thickness of plate ±0.1 Thickness of brake disc ±0.15 Depth of lining groove 0.8 (min.) — Thickness of lining 0.8 (min.) — Replace Standard size Tolerance Wear limit Wear of disc contact surface of...
Page 183 400 Brake system SEN03828-00 Brake Rear brake 1. Differential housing 2. Bearing carrier 3. Piston 4. Spring 5. Inner ring 6. Sun gear shaft 7. Axle housing 8. Outer ring 9. Disc (2 pieces) 10-400 WA250, 250PZ-6...
Page 184 400 Brake system SEN03828-00 Brake Unit: mm Check item Criteria Remedy Standard size Tolerance Repair limit Thickness of plate ±0.1 Thickness of brake disc ±0.15 Depth of lining groove 0.8 (min.) — Thickness of lining 0.8 (min.) — Replace Standard size Tolerance Wear limit Wear of disc contact surface of...
Page 185 400 Brake system SEN03828-00 Brake Operation When brake is operated As the brake pedal is pressed, oil pressure (P) being supplied through the hydraulic tank, pump and brake charge valve to the brake cyl- inder acts on piston (2) in the brake cylinder to move the piston.
Page 186: Parking Brake Control
400 Brake system SEN03828-00 Parking brake control Parking brake control 1. Parking brake lever 4. Control cable 2. Parking brake lever bottom switch 5. Transfer 3. Parking brake lever intermediate switch 6. Multi-disc brake lever Outline The parking brake is built in transfer (5). On this mechanical parking brake, operating the multi-disc brake lever (6) from parking brake lever (1) allows "applying"...
Page 187: Parking Brake
400 Brake system SEN03828-00 Parking brake Parking brake 1. Lever 5. Plate 2. Housing 6. Disc 3. Ball 7. Wave spring 4. Piston 8. Output shaft Unit: mm Check item Criteria Remedy Standard size Tolerance Repair limit Thickness of plate ±0.06 Strain on plate —...
Page 188 400 Brake system SEN03828-00 Parking brake WA250, 250PZ-6 10-400...
Page 189 SEN03828-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03828-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-400...
Page 190: Undercarriage And Frame Sen03829-00
SEN03829-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 500 Undercarriage and frame Axle mount and center hinge pin ........................2 Tires ................................7 WA250, 250PZ-6...
Page 191: Axle Mount And Center Hinge Pin
500 Undercarriage and frame SEN03829-00 Axle mount and center hinge pin Axle mount and center hinge pin The following drawing shows WA250-6. 10-500 WA250, 250PZ-6...
Page 192 500 Undercarriage and frame SEN03829-00 Axle mount and center hinge pin 1. Front axle Outline 2. Tension bolt Front axle (1) receives the force during work 3. Rear axle directly. Thus, it is fixed directly to front fame 4. Frame lock bar (5) with tension bolt (2).
Page 193 500 Undercarriage and frame SEN03829-00 Axle mount and center hinge pin 10-500 WA250, 250PZ-6...
Page 194 500 Undercarriage and frame SEN03829-00 Axle mount and center hinge pin Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Shaft Hole Clearance between upper hinge pin and rear frame (small) –0.030 +0.100 0.030 – — –0.049 0.149 Clearance between upper hinge pin...
Page 195 500 Undercarriage and frame SEN03829-00 Axle mount and center hinge pin Unit: mm Check item Criteria Remedy Standard size Tolerance Repair limit Thickness of thrust plate — –0.15 +0.3 Thickness of thrust washer — –0.1 Tolerance Replace Standard Standard Clearance size clearance limit...
Page 196: Tires
500 Undercarriage and frame SEN03829-00 Tires Tires The radial tires (if equipped) of this machine have the following features. High gripping force Low fuel consumption High operator comfort Long life Less frequency of burst Less damages of machine Less uneven wear Less generation of heat Comparison of structures and characteristics of tires Radial tire...
Page 197 SEN03829-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03829-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-500...
Page 198 SEN03830-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 600 Hydraulic system Work equipment hydraulic piping diagram ...................... 2 Work equipment control lever linkage ......................6 Hydraulic tank ...............................
Page 199: Work Equipment Hydraulic Piping Diagram
600 Hydraulic system SEN03830-00 Work equipment hydraulic piping diagram Work equipment hydraulic piping diagram WA250-6 10-600 WA250, 250PZ-6...
Page 200 600 Hydraulic system SEN03830-00 Work equipment hydraulic piping diagram 1. Work equipment control valve Outline 2. Bucket cylinder The hydraulic system is consisted of the HST, 3. Hydraulic tank steering, work equipment, brake, cooling fan 4. Work equipment PPC valve and transfer lubrication circuit.
Page 201 600 Hydraulic system SEN03830-00 Work equipment hydraulic piping diagram WA250PZ-6 10-600 WA250, 250PZ-6...
Page 202 600 Hydraulic system SEN03830-00 Work equipment hydraulic piping diagram 1. Bypass valve (for lift arm circuit) Outline 2. Work equipment control valve The hydraulic system is consisted of the HST, 3. Quick coupler solenoid valve steering, work equipment, brake, cooling fan 4.
Page 203: Work Equipment Control Lever Linkage
600 Hydraulic system SEN03830-00 Work equipment control lever linkage Work equipment control lever linkage WA250-6 Multi-function mono-lever type 1. Work equipment control lever 2. Directional selector switch 3. Wrist rest 4. Lock valve 5. Work equipment lock lever 6. Work equipment PPC valve 7.
Page 204 600 Hydraulic system SEN03830-00 Work equipment control lever linkage WA250-6 2-lever type (if equipped) 1. Lift arm control lever 2. Bucket control lever 3. Wrist rest 4. Lock valve 5. Work equipment lock lever 6. Work equipment PPC valve 7. Wrist rest height adjustment lever...
Page 205 600 Hydraulic system SEN03830-00 Work equipment control lever linkage WA250PZ-6 Multi-function mono-lever type 1. Work equipment control lever 2. Auxiliary control lever 3. Directional selector switch 4. Wrist rest 5. Lock valve 6. Work equipment lock lever 7. Work equipment PPC valve 8.
Page 206 600 Hydraulic system SEN03830-00 Work equipment control lever linkage WA250PZ-6 2-lever type (if equipped) 1. Lift arm control lever 2. Bucket control lever 3. Auxiliary control lever 4. Wrist rest 5. Lock valve 6. Work equipment lock lever 7. Attachment PPC valve 8.
Page 207: Hydraulic Tank
600 Hydraulic system SEN03830-00 Hydraulic tank Hydraulic tank 1. Oil filler cap and breather Specifications 2. Return filter Capacity of hydraulic tank (l) 3. Hydraulic tank 4. Drain plug Quantity of oil in hydraulic tank (l) 5. Sight gauge 6. Return filter bypass valve Set pressure of bypass valve 7.
Page 208 600 Hydraulic system SEN03830-00 Hydraulic tank Breather 1. Oil filler cap 2. Case 3. Lock-resetting knob 4. Sleeve 5. Poppet 6. Filter element Prevention of negative pressure in tank Since the tank is pressurized and enclosed, if the oil level in it lowers, negative pressure is generated.
Page 209: 4-Gear Pump
600 Hydraulic system SEN03830-00 4-gear pump 4-gear pump (steering, work equipment, brake, cooling fan and transfer lubrication) SAR (3)56 + (2)40 + SBR (1)12 + 12 1. Steering pump Outline 2. Work equipment pump The 4-gear pump is installed on the HST 3.
Page 210 600 Hydraulic system SEN03830-00 4-gear pump Unit: mm Check item Criteria Remedy Type Standard clearance Clearance limit SAR(3)56 Side clearance SAR(2)40 0.10 – 0.15 0.19 SBR(1)12 SBR(1)12 SAR(3)56 0.083 – 0.144 Clearance between inside diameter SAR(2)40 0.071 – 0.121 of plain bearing and outside 0.20 Replace SBR(1)12...
Page 211: Work Equipment Control Valve
600 Hydraulic system SEN03830-00 Work equipment control valve Work equipment control valve WA250-6 2-spool type 10-600 WA250, 250PZ-6...
Page 212 600 Hydraulic system SEN03830-00 Work equipment control valve A1: To bucket cylinder head A2: To lift arm cylinder head B1: To bucket cylinder bottom B2: To lift arm cylinder bottom P: From pump PA1: From work equipment PPC valve PA2: From work equipment PPC valve PB1: From work equipment PPC valve PB2: From work equipment PPC valve T: To hydraulic tank...
Page 213 600 Hydraulic system SEN03830-00 Work equipment control valve 10-600 WA250, 250PZ-6...
Page 214 600 Hydraulic system SEN03830-00 Work equipment control valve 1. Main relief valve 2. Bucket spool 3. Lift arm spool 4. Suction safety valve 5. Check valve 6. Suction valve Unit: mm Item Criteria Remedy Standard size Repair limit Free length x Installed Outside Installed load Free length Installed load...
Page 215 600 Hydraulic system SEN03830-00 Work equipment control valve WA250-6 3-spool type 10-600 WA250, 250PZ-6...
Page 216 600 Hydraulic system SEN03830-00 Work equipment control valve A1: To service actuator A2: To bucket cylinder head A3: To lift arm cylinder head B1: To service actuator B2: To bucket cylinder bottom B3: To lift arm cylinder bottom P: From pump PA1: To service PPC valve PA2: To work equipment PPC valve PA3: To work equipment PPC valve...
Page 217 600 Hydraulic system SEN03830-00 Work equipment control valve 10-600 WA250, 250PZ-6...
Page 218 600 Hydraulic system SEN03830-00 Work equipment control valve 1. Main relief valve 2. Service spool 3. Bucket spool 4. Lift arm spool 5. Suction safety valve 6. Check valve 7. Suction valve Unit: mm Item Criteria Remedy Standard size Repair limit Free length x Installed Outside...
Page 219 600 Hydraulic system SEN03830-00 Work equipment control valve WA250PZ-6 2-spool type 10-600 WA250, 250PZ-6...
Page 220 600 Hydraulic system SEN03830-00 Work equipment control valve A1: To bucket cylinder head A2: To lift arm cylinder head B1: To bucket cylinder bottom B2: To lift arm cylinder bottom P: From pump PA1: From work equipment PPC valve PA2: From work equipment PPC valve PB1: From work equipment PPC valve PB2: From work equipment PPC valve T: To hydraulic tank...
Page 221 600 Hydraulic system SEN03830-00 Work equipment control valve 10-600 WA250, 250PZ-6...
Page 222 600 Hydraulic system SEN03830-00 Work equipment control valve 1. Main relief valve 2. Bucket spool 3. Lift arm spool 4. Suction safety valve 5. Check valve 6. Suction valve Unit: mm Item Criteria Remedy Standard size Repair limit Free length x Installed Outside Installed load Free length Installed load...
Page 223 600 Hydraulic system SEN03830-00 Work equipment control valve WA250PZ-6 3-spool type 10-600 WA250, 250PZ-6...
Page 224 600 Hydraulic system SEN03830-00 Work equipment control valve A1: To service actuator A2: To bucket cylinder head A3: To lift arm cylinder head B1: To service actuator B2: To bucket cylinder bottom B3: To lift arm cylinder bottom P: From pump PA1: To service PPC valve PA2: To work equipment PPC valve PA3: To work equipment PPC valve...
Page 225 600 Hydraulic system SEN03830-00 Work equipment control valve 10-600 WA250, 250PZ-6...
Page 226 600 Hydraulic system SEN03830-00 Work equipment control valve 1. Main relief valve 2. Service spool 3. Bucket spool 4. Lift arm spool 5. Suction safety valve 6. Check valve 7. Suction valve Unit: mm Item Criteria Remedy Standard size Repair limit Free length x Installed Outside...
Page 227 600 Hydraulic system SEN03830-00 Work equipment control valve Relief valve As the pressurized oil in ports (A) and (B) reaches the set pressure of spring (4), pilot poppet (3) opens, leading the pressurized oil in port (B) to port (C) through port (D), and pres- sure in port (B) is decreased.
Page 228 600 Hydraulic system SEN03830-00 Work equipment control valve Suction safety valve 1. Piston 2. Main valve If abnormal pressure is generated in port (A) 3. Piston spring and reaches the set pressure of spring (6), 4. Valve seat poppet (5) opens to drain the pressurized oil in 5.
Page 229 600 Hydraulic system SEN03830-00 Work equipment control valve Suction valve Since the pressure in port (C) is lower than that in port (A), main valve (2) moves to the right and the pressurized oil is conducted from port (A) to port (B) to prevent generation of abnor- mal pressure.
Page 230 600 Hydraulic system SEN03830-00 Work equipment control valve Operation of work equipment control valve 1. When lift arm and bucket spool are at the neutral position Operation The pressurized oil flows to port (A) through pump (1) and the priority valve. And the maxi- mum pressure is regulated by relief valve (2).
Page 231 600 Hydraulic system SEN03830-00 Work equipment control valve 2. When lift arm spool is at raise position Operation Pulling the work equipment control lever pulls out lift arm spool (4) to set it to the raise posi- tion. The pressurized oil from pump (1) flows to the bypass circuit of lift arm spool (4) through the bypass circuit of bucket spool (3).
Page 232 600 Hydraulic system SEN03830-00 Work equipment control valve 3. When lift arm spool is at lower position Operation Pushing the work equipment control lever pushes in lift arm spool (4) to set it to the lower position. The pressurized oil from pump (1) flows to the bypass circuit of lift arm spool (4) through the bypass circuit of bucket spool (3).
Page 233 600 Hydraulic system SEN03830-00 Work equipment control valve 4. When lift arm spool is at float position Operation Pushing the work equipment control lever fur- As long as the bucket is contacting against the ther from the lower position pushes in lift arm ground surface, the lift arm can be raised or spool (4) to set it to the float position.
Page 234 600 Hydraulic system SEN03830-00 Work equipment control valve 5. When bucket spool is at tilt position Operation Pulling the work equipment control lever pulls out bucket spool (3) to set it to the tilt position. Since the bypass circuit is closed by the spool, the pressurized oil from port (A) pushes open check valve (7).
Page 235 600 Hydraulic system SEN03830-00 Work equipment control valve 6. When bucket spool is at dump position Operation Pushing the work equipment control lever pushes in bucket spool (3) to set it to the dump position. Since the bypass circuit is closed by the spool, the pressurized oil from port (A) pushes open check valve (7).
Page 236: Ppc Valve
600 Hydraulic system SEN03830-00 PPC valve PPC valve a PPC: Abbreviation for Proportional Pressure Control Work equipment PPC valve Mono lever type P: From HST charge pump P3: To lift arm valve (raise) P1: To bucket valve (tilt) P4: To lift arm valve (lower, float) P2: To bucket valve (dump) T: To hydraulic tank WA250, 250PZ-6...
Page 237 600 Hydraulic system SEN03830-00 PPC valve 1. Spool 7. Joint 2. Metering spring 8. Plate 3. Centering spring 9. Piston 4. Rod 10. Retainer 5. Disc 11. Body 6. Nut (for connecting lever) 12. Filter 10-600 WA250, 250PZ-6...
Page 238 600 Hydraulic system SEN03830-00 PPC valve Operation 1. When in neutral 1) Bucket PPC valve 2) Lift arm PPC valve Ports (PA) and (PB) of the control valve Ports (PA) and (PB) of the control valve (lift (bucket valve) and ports (P1) and (P2) of the arm valve) and ports (P3) and (P4) of the PPC PPC valve are connected through fine control valve are connected through fine control hole...
Page 239 600 Hydraulic system SEN03830-00 PPC valve 2. When in fine control mode (neutral o fine control) If rod (4) and piston (9) are pushed by disc (5), retainer (10) is pushed and spool (1) is also pushed downward through metering spring (2). When fine control hole (f) is shut off from drain chamber (D), almost simultaneously, it is con- nected to pump pressure chamber (PP).
Page 240 600 Hydraulic system SEN03830-00 PPC valve 3. When in fine control mode 4. When lever is operated to stroke end (when control lever is returned) Disc (5) and rod (4) push down piston (9) and As disc (5) begins to return, the force of center- retainer (10) pushes down spool (1).
Page 241 600 Hydraulic system SEN03830-00 PPC valve 5. When lift arm is "float" If disc (5) pushes down rod (4) and piston (9) on port (P4) "lower" side, the detent starts operation before the stroke end. (the operating effort of the lever becomes heavy.) If rod (4) is pushed down further, the detent operates to keep the lift arm in "float"...
Page 242 600 Hydraulic system SEN03830-00 PPC valve 2-lever type (if equipped) P: From HST charge pump P1: To bucket tilt valve P2: To lift arm LOWER (FLOAT) valve P3: To lift arm RAISE valve P4: To bucket DUMP valve T: To hydraulic tank WA250, 250PZ-6 10-600...
Page 243 600 Hydraulic system SEN03830-00 PPC valve 1. Spool 7. Plate 2. Metering spring 8. Piston 3. Centering spring 9. Retainer 4. Rod 10. Body 5. Lever 11. Filter 6. Ring 10-600 WA250, 250PZ-6...
Page 244 600 Hydraulic system SEN03830-00 PPC valve Operation 1. When in neutral 1) Bucket PPC valve 2) Lift arm PPC valve Ports (PA) and (PB) of the control valve Ports (PA) and (PB) of the control valve (lift (bucket valve) and ports (P1) and (P4) of the arm valve) and ports (P2) and (P3) of the PPC PPC valve are connected through fine control valve are connected through fine control hole...
Page 245 600 Hydraulic system SEN03830-00 PPC valve 2. When in fine control mode (neutral o fine control) If rod (4) and piston (8) are pushed by lever (5), retainer (9) is pushed and spool (1) is also pushed downward through metering spring (2). When fine control hole (f) is shut off from drain chamber (D), almost simultaneously, it is con- nected to pump pressure chamber (PP).
Page 246 600 Hydraulic system SEN03830-00 PPC valve 3. When in fine control mode 4. When lever is operated to stroke end (when control lever is returned) Lever (5) and rod (4) push down piston (8) and If lever (5) begins to return, the force of center- retainer (9) pushes down spool (1).
Page 247 600 Hydraulic system SEN03830-00 PPC valve 5. When lift arm is "float" As lever (5) pushes down rod (4) and piston (8) on port (P3) "lower" side, the detent starts operation before the stroke end. (the operating effort of the lever becomes heavy.) If rod (4) is pushed down further, the detent operates to keep the lift arm in "float"...
Page 248 600 Hydraulic system SEN03830-00 PPC valve WA250, 250PZ-6 10-600...
Page 249 600 Hydraulic system SEN03830-00 PPC valve Attachment PPC valve (if equipped) a For the details of operation, see the paragraph of "Work equipment PPC valve". 10-600 WA250, 250PZ-6...
Page 250 600 Hydraulic system SEN03830-00 PPC valve P: From self pressure reducing valve P1: To attachment valve P2: To attachment valve T: To hydraulic tank 1. Spool 2. Piston 3. Lever 4. Plate 5. Retainer 6. Body 7. Filter Unit: mm Item Criteria Remedy...
Page 251: Lock Valve
600 Hydraulic system SEN03830-00 Lock valve Lock valve 1. Lever 2. End cap 3. Ball 4. Seat 5. Body Outline The lock valve is installed between the HST charge pump and work equipment PPC valve. As the work equipment lock lever is set to the "Lock"...
Page 252: Accumulator (For Ppc Circuit)
600 Hydraulic system SEN03830-00 Accumulator (for PPC circuit) Accumulator (for PPC circuit) 1. Gas plug 2. Poppet 3. Holder 4. Bladder 5. Film 6. Shell 7. Oil port Outline The accumulator is installed between the charge valve and work equipment PPC valve. Even if the engine stops with the work equip- ment raised, the pressure of the compressed nitrogen gas in the accumulator applies the...
Page 253: Bypass Valve
600 Hydraulic system SEN03830-00 Bypass valve Bypass valve WA250PZ-6 PP: From work equipment PPC valve port P4 1. Body T: From work equipment PPC valve port P3 2. Plunger A: To lift cylinder bottom side 3. Plug B: To lift cylinder head side 4.
Page 254 600 Hydraulic system SEN03830-00 Bypass valve Operation When lift arm is "RAISE" operation If the lift arm is "RAISE" operation, the oil of the work equipment PPC valve operates the work equipment control valve and the oil from the work equipment pump flows to the lift cylinder bottom side.
Page 255 600 Hydraulic system SEN03830-00 Bypass valve When lift arm is "LOWER" operation If the lift arm is "LOWER" operation, the oil of the work equipment PPC valve operates the work equipment control valve and the oil from the work equipment pump flows to the lift cylin- der head side.
Page 256: Quick Coupler Solenoid Valve
600 Hydraulic system SEN03830-00 Quick coupler solenoid valve Quick coupler solenoid valve WA250PZ-6 P: From work equipment control valve port B2 Outline T: To work equipment control valve port A2 When an attachment is installed or removed, A: To coupler plunger head side the quick coupler solenoid valve changes the B: To coupler plunger bottom side oil flow for the coupler plunger electrically to...
Page 257: Ecss Valve
600 Hydraulic system SEN03830-00 ECSS valve ECSS valve (if equipped) a ECSS: Abbreviation for Electronically Controlled Suspension System P: From work equipment pump T: To hydraulic tank A: From lift cylinder bottom B: From lift cylinder head SP: To accumulator (for ECSS) 10-600 WA250, 250PZ-6...
Page 258 600 Hydraulic system SEN03830-00 ECSS valve 1. Main spool 2. Solenoid valve 3. Flow control valve 4. Shuttle valve 5. Charge valve WA250, 250PZ-6 10-600...
Page 259: Accumulator (For Ecss)
600 Hydraulic system SEN03830-00 Accumulator (for ECSS) Accumulator (for ECSS) (if equipped) 1. Valve 2. Top cover 3. Cylinder 4. Free piston Function The accumulator is installed to the lift cylinder bottom circuit. The space between cylinder (3) and free piston (4) is filled with nitrogen gas. The nitrogen gas absorbs the oil pressure pulses generated on the lift cylinder bottom side during travel for higher travel performance...
Page 260 600 Hydraulic system SEN03830-00 Accumulator (for ECSS) WA250, 250PZ-6 10-600...
Page 261 SEN03830-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03830-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-600...
Page 262: Structure, Function And Maintenance Standard
SEN03831-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 700 Work equipment Work equipment linkage ..........................2 Bucket ................................6 Bucket positioner and boom kick-out ......................10 Work equipment cylinder ..........................
Page 263: Work Equipment Linkage
700 Work equipment SEN03831-00 Work equipment linkage Work equipment linkage WA250-6 10-700 WA250, 250PZ-6...
Page 264: Bucket
700 Work equipment SEN03831-00 Work equipment linkage 1. Bucket 2. Bell crank 3. Bucket cylinder 4. Lift cylinder 5. Lift arm 6. Bucket link Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between bushing and pin Shaft Hole at each end of bucket link...
Page 265 700 Work equipment SEN03831-00 Work equipment linkage WA250PZ-6 10-700 WA250, 250PZ-6...
Page 266 700 Work equipment SEN03831-00 Work equipment linkage 1. Bucket 2. Bell crank 3. Bucket cylinder 4. Lift cylinder 5. Lift arm 6. Bucket link 7. Quick coupler Unit: mm Check item Criteria Remedy Tolerance Standard Standard Clearance size clearance limit Clearance between bushing and pin Shaft Hole...
Page 267 700 Work equipment SEN03831-00 Bucket Bucket WA250-6 1. Bucket 3. Bucket teeth (if equipped) 2. Bolt-on cutting edge 4. Adapter (if equipped) 10-700 WA250, 250PZ-6...
Page 268 700 Work equipment SEN03831-00 Bucket Unit: mm Check item Criteria Remedy Standard size Repair limit Wear of cutting edge (thickness) 31.8 Reverse or replace Wear of cutting edge (length) Tooth Wear of bucket teeth Replace Tip tooth Clearance in adapter mounting Max.
Page 269 700 Work equipment SEN03831-00 Bucket WA250PZ-6 1. Bucket 3. Bucket teeth (if equipped) 2. Bolt-on cutting edge 4. Adapter (if equipped) 10-700 WA250, 250PZ-6...
Page 270 700 Work equipment SEN03831-00 Bucket Unit: mm Check item Criteria Remedy Standard size Repair limit Wear of cutting edge (thickness) 31.8 Reverse or replace Wear of cutting edge (length) Tooth Wear of bucket teeth Replace Tip tooth Clearance in adapter mounting Max.
Page 271: Bucket Positioner And Boom Kick-Out
700 Work equipment SEN03831-00 Bucket positioner and boom kick-out Bucket positioner and boom kick-out WA250-6 1. Bucket positioner proximity switch 4. Bucket cylinder 2. Boom kick-out proximity switch 5. Lift arm 3. Bar 6. Plate Unit: mm Check item Criteria...
Page 272 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out Outline Bucket positioner The bucket positioner is driven electrically. When the bucket is returned to an angle from the dump position to the tilt position, the bucket positioner returns the work equipment (bucket) control lever from the "tilt"...
Page 273 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out Operation of proximity switch When bucket is tilted While the bucket is dumped more than the Shifting work equipment (bucket) control lever position being set from the bucket positioner, (7) toward the tilt position moves spool (8) to bar (2) moves on to the sensing face of prox- the position of the arrow.
Page 274 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out a The power supply for detent solenoid (6) oper- ation is turned "ON" or "OFF" by alternator relay (11). Detent solenoid (6) circuit is turned off since L signal from alternator (10) is not sent to alter- nator relay (11) as long as the engine is stopped.
Page 275 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out When lift arm is raised While lift arm (3) is dumped beyond the posi- Shifting work equipment (lift arm) control lever tion set from the boom kick-out, plate (2) (7) toward the raise position moves spool (8) to moves on to the sensing face of proximity the position of the arrow.
Page 276 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out a The power supply for detent solenoid (6) oper- ation is turned "ON" or "OFF" by alternator relay (11). Detent solenoid (6) circuit is cut off since L sig- nal from alternator (10) is not sent to alternator relay (11) as long as the engine is stopped.
Page 277 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out WA250PZ-6 1. Fork positioner proximity switch 5. Bucket cylinder 2. Bucket positioner proximity switch 6. Lift arm 3. Boom kick-out proximity switch 7. Plate 4. Bar Unit: mm Check item Criteria Remedy Clearance on bucket positioner 3 –...
Page 278 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out Outline Bucket positioner or fork positioner The bucket positioner is driven electrically. When the bucket or fork is returned to an angle from the dump position to the tilt position, the bucket positioner returns the work equipment (bucket or fork) control lever from the "tilt"...
Page 279 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out Operation of proximity switch When bucket is tilted a The case when the attachment selector switch is in the "BUCKET" position is shown below. While the bucket is dumped more than the Shifting work equipment (bucket) control lever position being set from the bucket positioner, (7) toward the tilt position moves spool (8) to...
Page 280 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out a The power supply for detent solenoid (6) oper- ation is turned "ON" or "OFF" by alternator relay (11). Detent solenoid (6) circuit is turned off since L signal from alternator (10) is not sent to alter- nator relay (11) as long as the engine is stopped.
Page 281 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out When lift arm is raised While lift arm (3) is dumped beyond the posi- Shifting work equipment (lift arm) control lever tion set from the boom kick-out, plate (2) (7) toward the raise position moves spool (8) to moves on to the sensing face of proximity the position of the arrow.
Page 282 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out a The power supply for detent solenoid (6) oper- ation is turned "ON" or "OFF" by alternator relay (11). Detent solenoid (6) circuit is cut off since L sig- nal from alternator (10) is not sent to alternator relay (11) as long as the engine is stopped.
Page 283 700 Work equipment SEN03831-00 Bucket positioner and boom kick-out 10-700 WA250, 250PZ-6...
Page 284: Work Equipment Cylinder
700 Work equipment SEN03831-00 Work equipment cylinder Work equipment cylinder WA250-6 Lift cylinder Bucket cylinder Unit: mm Check item Criteria Remedy Tolerance Cylinder Standard Standard Clearance name size clearance limit Shaft Hole Clearance between piston –0.030 +0.271 0.105 – Replace bushing Lift 0.675...
Page 285 700 Work equipment SEN03831-00 Work equipment cylinder WA250PZ-6 Lift cylinder Bucket cylinder Coupler plunger 10-700 WA250, 250PZ-6...
Page 286 700 Work equipment SEN03831-00 Work equipment cylinder Unit: mm Check item Criteria Remedy Tolerance Cylinder Standard Standard Clearance name size clearance limit Shaft Hole –0.030 +0.271 0.105 – Lift 0.675 Clearance between piston –0.104 +0.075 0.375 Replace bushing rod and bushing –0.035 +0.270 0.095 –...
Page 287 SEN03831-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03831-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-700...
Page 288: Cab And Its Attachments Sen03832-00
SEN03832-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 800 Cab and its attachments Cab ................................. 3 Air conditioner ..............................4 WA250, 250PZ-6 10-800...
Page 289 800 Cab and its attachments SEN03832-00 10-800 WA250, 250PZ-6...
Page 290: Cab
800 Cab and its attachments SEN03832-00 1. Front working lamp 2. Radio antenna 3. Door (left) 4. Air conditioner external air filter 5. Front glass 6. Front wiper 7. KOMTRAX GPS antenna 8. KOMTRAX communication antenna 9. Door (right) 10. Rear wiper WA250, 250PZ-6 10-800...
Page 291: Air Conditioner
800 Cab and its attachments SEN03832-00 Air conditioner Air conditioner Air conditioner piping diagram 10-800 WA250, 250PZ-6...
Page 292 800 Cab and its attachments SEN03832-00 Air conditioner 1. Hot water take-out piping Specifications 2. Compressor Refrigerant used R134a 3. Condenser Refrigerant refilling level (g) 4. Receiver 5. Hot water return piping 6. Refrigerant piping 7. External air filter 8. Internal/external air changeover damper 9.
Page 293 800 Cab and its attachments SEN03832-00 Air conditioner Refrigerant circuit diagram 1. Engine 2. Compressor 3. Condenser 4. Receiver 5. Air conditioner unit 6. Dual pressure switch Table of tightening torque for refrigerant piping adapter Unit: Nm {kgm} Check item Criteria Remedy 12 –...
Page 294 800 Cab and its attachments SEN03832-00 Air conditioner Air conditioner unit A: From receiver Outline B: To compressor The vertical air conditioner unit on which evap- C: Hot water inlet orator (1) and heater core (2) is synchronized D: Hot water outlet with the blower and intake unit to generate cool and hot air.
Page 295 800 Cab and its attachments SEN03832-00 Air conditioner Functions of major components Air mix damper actuator Evaporator It starts the built-in motor receiving signal cur- rent from the air conditioner panel in order to Evaporator fin is cooled by the low-pressure, open or close the air mix damper through the low-temperature refrigerant gas being sent link mechanism.
Page 296 800 Cab and its attachments SEN03832-00 Air conditioner Blower and intake unit 1. Blower motor assembly Functions of major components 2. Internal/external air changeover damper actuator Blower motor assembly 3. Internal/external air changeover damper It suctions air by rotating the fin installed on the blower motor.
Page 297 800 Cab and its attachments SEN03832-00 Air conditioner Compressor A: From air conditioner unit Function B: To condenser Other than circulating the refrigerant, it com- presses the refrigerant gas from the evapora- tor to high-pressure, high-temperature misty refrigerant so that it may be easily regenerated (liquefied) at normal temperature.
Page 298 800 Cab and its attachments SEN03832-00 Air conditioner Condenser A: From compressor Function B: To receiver It cools and liquefies the high-pressure and high-temperature misty refrigerant from the compressor. If the fin crushes or is clogged with dusts, heat exchange efficiency is degraded and complete liquefaction of refrigerant becomes unavail- able.
Page 299 800 Cab and its attachments SEN03832-00 Air conditioner Receiver A: From condenser Function B: To air conditioner unit It is used to store liquefied high-pressure, high- temperature misty refrigerant from the con- 1. Sight glass denser. It is capable of completely liquefying the refrigerant even when bubbles are con- tained in the refrigerant due to the condenser condition in heat dissipation.
Page 300 800 Cab and its attachments SEN03832-00 Air conditioner WA250, 250PZ-6 10-800...
Page 301 800 Cab and its attachments SEN03832-00 Air conditioner Air conditioner panel Display unit Display Display Display items Display range Display method Remarks category color Spurting out All segments below applicable level come See above drawing temperature on (8-step display) Gauge Air blasting All segments below applicable level come See above drawing...
Page 302 800 Cab and its attachments SEN03832-00 Air conditioner Outline CPU (central processing unit) installed on the panel processes input signals from respective sensors and operation signals of the panel switches to display and output them. The self-diagnosis function of CPU makes the troubleshooting easier.
Page 303 SEN03832-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03832-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 10-800...
Page 304: Electrical System, Part
SEN03833-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 910 Electrical system, Part 1 Machine monitor system ..........................2 Machine monitor ............................. 6 WA250, 250PZ-6 10-910...
Page 305: Machine Monitor System
910 Electrical system, Part 1 SEN03833-01 Machine monitor system Machine monitor system Outline In the machine monitor system, each controller In addition to the above, the following display, on the network monitors controls the machine setting and adjustment functions are provided condition with the sensors installed to various using the character display and the machine parts of the machine, and then sends the result...
Page 306 910 Electrical system, Part 1 SEN03833-01 Machine monitor system The service mode function is provided for the Optional device selecting function ease of troubleshooting for the controllers on Verifies the installation of optional devices or the network (including the machine monitor changes their setting.
Page 307 910 Electrical system, Part 1 SEN03833-01 Machine monitor system System circuit diagram a Items marked with "*1" in drawing may or may not installed. 10-910 WA250, 250PZ-6...
Page 308 910 Electrical system, Part 1 SEN03833-01 Machine monitor system WA250, 250PZ-6 10-910...
Page 309: Machine Monitor
910 Electrical system, Part 1 SEN03833-01 Machine monitor Machine monitor HST oil temperature gauge 20. Brake oil temperature caution lamp HST oil temperature caution lamp 21. Quick coupler operation pilot lamp (*2) Engine coolant temperature gauge 22. Cooling fan reverse rotation pilot lamp Engine coolant temperature caution lamp 23.
Page 310: Electrical System, Part
910 Electrical system, Part 1 SEN03833-01 Machine monitor List of items displayed on monitor Condition for judging that the engine is running: If 2 or more are met in the following 3 conditions, the engine is judged running when the abnormality in the CAN communication occurs and the charge level exceeds the specified level.
Page 311 910 Electrical system, Part 1 SEN03833-01 Machine monitor Detecting Operating condition time Engine stopped Engine is running (sec) Category Item Device Operating condition Remarks Operates when charging Service meter normally at 1 : 1 to the — — — — — — Displays various codes and clock time Character...
Page 312 910 Electrical system, Part 1 SEN03833-01 Machine monitor Detecting Operating condition time Engine stopped Engine is running (sec) Category Item Device Operating condition Remarks Operation (OPEN) — Q — — Q — Released (CLOSE) — — — — — — 19 Parking brake Engine is running, parking brake operated and the...
Page 313 910 Electrical system, Part 1 SEN03833-01 Machine monitor Detecting Operating condition time Engine stopped Engine is running (sec) Category Item Device Operating condition Remarks Other than below — — — — — — 30 Preheating When preheater is turned — Q — —...
Page 314 910 Electrical system, Part 1 SEN03833-01 Machine monitor Machine monitor operation switch 1. Machine monitor mode selector switch 1 2. Machine monitor mode selector switch 2 WA250, 250PZ-6 10-910...
Page 315 910 Electrical system, Part 1 SEN03833-01 Machine monitor Setting of machine monitor 1. Spare rotary switch (SW1) 2. Spare rotary switch (SW2) 3. Spare rotary switch (SW3) 4. Spare dip switch (SW5-1) 5. Spare dip switch (SW5-2) 6. Spare dip switch (SW5-3) 7.
Page 316 910 Electrical system, Part 1 SEN03833-01 Machine monitor Character display function Machine monitor display and setting can be changed by using the character display. The range where operator is enabled to operate is within the portion of the "Operator mode" in the figure below.
Page 317 910 Electrical system, Part 1 SEN03833-01 Machine monitor Operator mode functions Self-check screen (0th layer) Self-check is conducted for 3 seconds automatically when starting switch is turned to "ON". During a self-check, entry through the machine monitor operating switch is not accepted. After ending the self-check, the self-check screen automatically moves to 1st layer.
Page 318 910 Electrical system, Part 1 SEN03833-01 Machine monitor Failure code screen (1st layer) Pressing the ">" switch while the Warning screen is on display changes display to the Failure code screen. If multiple failure codes are present, pressing of the ">" switch sequentially displays them from the item of higher priority downward.
Page 319 910 Electrical system, Part 1 SEN03833-01 Machine monitor Display of functions opened to the operator (2nd layer or below) Certain menus are not displayed unless the items in the "Optional device selecting function" of the machine monitor are set. Pressing " "...
Page 320 910 Electrical system, Part 1 SEN03833-01 Machine monitor Service mode functions The machine monitor is provided with service mode function for the ease of troubleshooting for the con- trollers on the network (including the machine monitor itself). Initial setting of the sensors and optional setting can be made in the service mode of the machine moni- tor.
Page 321 910 Electrical system, Part 1 SEN03833-01 Machine monitor Service mode menu a Pressing "<" or ">" switch on the menu screen switches individual menus of the service mode sequen- tially and endlessly. a Pressing " " switch on the target menu screen changes the screen to the detailed screen of the same menu.
Page 322 910 Electrical system, Part 1 SEN03833-01 Machine monitor Electrical system failure history display func- Real-time monitoring function (REAL-TIME tion (ELECTRIC FAULT) MONITOR) a "**" field displays total number of the failure This function is used to check on the input/out- history currently recorded.
Page 323 910 Electrical system, Part 1 SEN03833-01 Machine monitor No injection cranking function (NO INJECTION) Maintenance monitoring function (MAINTE- NANCE MONITOR) Before restarting engine after a long-term stor- ing of the machine, this function is used to This function is used for changing the filter and lubricate the engine internally.
Page 324 910 Electrical system, Part 1 SEN03833-01 Machine monitor Optional device selecting function (OPTIONAL Model selection function (MACHINE) SELECT) This function is used for displaying or changing This function is used for verifying the installed the setting of model information (machine state of optional devices or when changing name).
Page 325 910 Electrical system, Part 1 SEN03833-01 Machine monitor Input and output signals AMP070-20P[CN-L24] Pin No. Specifications Group Form of use Signal name Remarks (NC) — — — — (NC) — — — — (NC) — — — — Constant power NSW power supply (+24 V) —...
Page 326 910 Electrical system, Part 1 SEN03833-01 Machine monitor AMP070-18P(1)[CN-L25] Pin No. Specifications Group Form of use Signal name Remarks D_IN_0 D/I (+24 V) Head lamp (24 V, 5 mA) D_IN_2 D/I (+24 V) Starting switch C signal (24 V, 5 mA) (NC) —...
Page 327 910 Electrical system, Part 1 SEN03833-01 Machine monitor AMP070-18P(2)[CN-L27] Pin No. Specifications Group Form of use Signal name Remarks D_IN_26 D/I (GND) Parking brake (24 V/GND, 5 mA) D_IN_28 Parking brake left-unapplied D/I (GND) (24 V/GND, 5 mA) prevention D_IN_30 D/I (GND) Normal emergency steering If equipped...
Page 328 910 Electrical system, Part 1 SEN03833-01 Machine monitor AMP070-12P(3)[CN-L29] Pin No. Specifications Group Form of use Signal name Remarks (NC) — — — — (NC) — — — — CAN (+) CAN (+) (NC) — — — — (NC) — —...
Page 329 910 Electrical system, Part 1 SEN03833-01 Machine monitor AMP040-8P Pin No. Specifications Group Form of use Signal name Remarks Do not connect (NC) — — — — wiring harness on machine Do not connect (NC) — — — — wiring harness on machine Do not connect (NC)
Page 330 910 Electrical system, Part 1 SEN03833-01 Machine monitor WA250, 250PZ-6 10-910...
Page 331 SEN03833-01 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03833-01 ©2007 KOMATSU All Rights Reserved Printed in Japan 10-07 (01) 10-910...
Page 332: Structure, Function And Maintenance Standard
SEN03834-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 10 Structure, function and maintenance standard 920 Electrical system, Part 2 Electrical system (HST controller system) ...................... 2 HST controller ............................... 18 ECSS system..............................20 KOMTRAX system............................
Page 333: Electrical System (Hst Controller System)
920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Electrical system (HST controller system) a Except where otherwise specified, the displayed travel speed in this document represents the one when 20.5-25 tire is worn. Input and output signals diagram o A HST motor 1 solenoid Travel speed range selector switch o D HST motor 2 solenoid relay...
Page 334 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) HST controller gear shifting control function Gear shifting function Receiving the travel speed range selector signal and the variable shift control signal, this function con- trols HST motor 1, HST motor 2 and transfer clutch in such that the maximum travel speed suited for the given state is produced.
Page 335 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) 1. HST pump 5. Clutch solenoid valve 2. HST motor 1 6. HST motor 1 solenoid valve 3. HST motor 2 7. HST motor 2 solenoid valve 4. Transfer clutch 8.
Page 336 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Traction control function Receiving the traction control signal, this function derates the maximum capacity of HST motor 1 to con- trol the traction force. "Traction level selecting function" of the machine monitor allows selecting a desired traction force out of 3 levels (A, B and C).
Page 337 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) The maximum traction force available when the travel speed range selector switch is set to "1st" and the traction control switch is set to "ON" When the travel speed range selector switch (1) is set to "1st"...
Page 338 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Max. traction function Pressing the max. traction switch while the traction control is "ON" or the S mode is selected cancels the traction control or the S mode temporarily to increase the maximum drawbar pull. If the directional lever or directional selector switch is operated, or the max.
Page 339 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) HST controller protection function HST motor 1 overrun prevention function 1 If the 1st or 2nd speed is selected while the machine is traveling at a high speed with the travel speed range selector switch being set to the 3rd or 4th, the transfer clutch is engaged during the high speed travel, preventing HST motor 1 to overrun beyond the allowable rotating speed.
Page 340 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) HST motor 1 overrun prevention function 2 Downhill travel at 1st or 2nd gear speed tends to allow the machine to increase the travel speed. This function prevents the rotational speed of HST motor 1 goes beyond the allowable rotating speed. In order to restrict the travel speed, the function controls the HST motor 1 capacity to the allowable max- imum if the travel speed goes beyond 14 km/h.
Page 341 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Economy operation pilot lamp function In order to prompt the operator for the low fuel consumption operation, this function lights up the econ- omy operation pilot lamp as long as the low fuel consumption operation is continued. The economy operation pilot lamp lights up as the opening ratio of the accelerator pedal is maintained at less than 75% for 0.5 seconds or longer.
Page 342 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Cooling fan control function 1. HST controller Input and output signals 2. Machine monitor HST controller 3. Engine controller a. CAN signal 4. Cooling fan pump b. Cooling fan motor flow rate control signal 5.
Page 343 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Fan control Employment of the hydraulically driven cooling fan and the control of the flow rate of the hydraulic motor allow reducing the horsepower loss and noises as well as cutting the warm-up operation time in a low temperature environment.
Page 344 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Control at start of engine In order to protect the fan from being stopped by low oil temperature or settled snow or dusts, the fan speed is temporarily increased immediately after the engine is started to aid start of the fan rotation. After the basic control is turned on, normal fan control is carried on based on the procedure described in the section of "Fan speed in accordance with temperature".
Page 345 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Fan reverse rotation function As the fan reverse rotation switch is pressed for cleaning of the radiator core, the cooling fan reverse rotation solenoid valve of the cooling fan motor is activated, reverse rotating the fan. Fan manual reverse rotation function The operator can select the desired fan rotation direction by pressing the fan reverse rotation switch to "MANUAL"...
Page 346 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) Fan automatic reverse rotation function Setting the fan reverse rotation switch to "AUTO" allows changing the fan rotation direction switching cycle and the reverse rotation duration at a specific interval. As long as switching of the fan rotation direction is taking place, the pilot lamps of the machine monitor keeps blinking to inform the operator that the switching is underway.
Page 347 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) System circuit diagram a Items marked with "*1" in drawing may or may not installed. 10-920 WA250, 250PZ-6...
Page 348 920 Electrical system, Part 2 SEN03834-01 Electrical system (HST controller system) WA250, 250PZ-6 10-920...
Page 349: Hst Controller
920 Electrical system, Part 2 SEN03834-01 HST controller HST controller Input and output signals DEUTSCH-40P [CN-HST] Input/Output Input/Output Signal name Signal name signal signal VB (controller power) Input 21 GND (controller GND) — Starting switch ACC signal Input 22 HST sensor power 5V Input Wake up Input...
Page 350 920 Electrical system, Part 2 SEN03834-01 HST controller WA250, 250PZ-6 10-920...
Page 351: Ecss System
920 Electrical system, Part 2 SEN03834-01 ECSS system ECSS system (if equipped) a ECSS: Abbreviation for Electronically Controlled Suspension System 1. HST controller Outline 2. Machine monitor When the machine travels at high speed, the 3. ECSS switch damping effect of the accumulator charged 4.
Page 352 920 Electrical system, Part 2 SEN03834-01 ECSS system The operating condition of PPC oil pressure Operation switch is as follows. The operating condition of ECSS is as follows. ECSS operation ECSS switch Travel speed [km/h] signal 0 – Max. (*2) Max. 4 (*1) Min.
Page 353: Komtrax System
920 Electrical system, Part 2 SEN03834-01 KOMTRAX system KOMTRAX system KOMTRAX terminal transmits various machine information by use of the radio communication. The KOMTRAX operator is allowed to reference these information in the office and offer them to the cus- tomer through various services.
Page 354 920 Electrical system, Part 2 SEN03834-01 KOMTRAX system KOMTRAX terminal 1. Communication antenna connector 2. GPS antenna connector 3. Machine harness connector (DEUTSCH-40P) Input and output signals DEUTSCH-40P [CN-L80] Input/Output Input/Output Pin No. Signal name Pin No. Signal name signal signal —...
Page 355: Engine Starting Circuit
920 Electrical system, Part 2 SEN03834-01 Engine starting circuit Engine starting circuit 1. Battery Function 2. Battery relay The neutral safety circuit is employed to 3. Slow-blow fuse secure safety when the engine is started. 4. Fuse box 1 The engine can not be started while the 5.
Page 356 920 Electrical system, Part 2 SEN03834-01 Engine starting circuit Operation When starting switch is turned "ON" As the starting switch is turned "ON", ter- minals B and BR of the starting switch are closed and the current flows from the bat- tery through the starting switch and bat- tery relay coil to the ground, thereby closing the contact of the battery relay.
Page 357: Engine Stopping Circuit
920 Electrical system, Part 2 SEN03834-01 Engine stopping circuit Engine stopping circuit Operation Setting the starting switch to "OFF" cuts off ACC signal from the starting switch terminal ACC to the engine controller. Although ACC is cut off, the engine controller keeps the engine controller cut-out relay work- ing to maintain the current flow to the engine controller until its internal processing is com-...
Page 358: Preheating Circuit
920 Electrical system, Part 2 SEN03834-01 Preheating circuit Preheating circuit 1. Battery Operation 2. Battery relay Set the starting switch to "ON" to start the 3. Slow-blow fuse engine controller. At this time, if intake air tem- 4. Fuse box 1 perature is -4°C or below, the engine controller 5.
Page 359: Engine Output Derating Function
920 Electrical system, Part 2 SEN03834-01 Engine output derating function Engine output derating function Automatic warm-up function If the engine controller detects a failure, it pro- When starting the engine in a cold district, this tects the engine by derating the engine torque function warms it up by increasing the engine or speed.
Page 360: Parking Brake Circuit
920 Electrical system, Part 2 SEN03834-01 Parking brake circuit Parking brake circuit 1. Parking brake lever intermediate switch 2. Parking brake lever bottom switch 3. HST controller 4. Machine monitor 5. Alarm buzzer 6. HST controller power holding relay 7. HST safety relay 8.
Page 361 920 Electrical system, Part 2 SEN03834-01 Parking brake circuit Operation Starting switch position State of engine Stopped Running Parking brake lever area Free Lock Free Lock Free Lock Parking brake lever Close Open Close Open Close Open intermediate switch (1) Parking brake lever bottom switch (2) Close...
Page 362 920 Electrical system, Part 2 SEN03834-01 Parking brake circuit When the parking brake lever is set to "Lock" position Pulling the parking brake lever fully opens both the intermediate switch (1) and bottom switch (2). The parking brake pilot lamp comes on only when the starting switch is "ON".
Page 363: Coupler Plunger Control System
920 Electrical system, Part 2 SEN03834-01 Coupler plunger control system Coupler plunger control system WA250PZ-6 Outline The coupler plunger is extracted or retracted by operating the quick coupler attachment switch to connect and release each attachment and the coupler. Operation When quick coupler attachment switch is in When quick coupler attachment switch is in "Release"...
Page 364: Multi-Function Knob
920 Electrical system, Part 2 SEN03834-01 Multi-function knob Multi-function knob 1. Directional selector switch Function 2. Max. traction switch Directional selector switch (1) is an alternate 3. Option switch [Reserved] type. Its control signal sent to the HST control- ler causes switching between the forward and reverse travel.
Page 365: Max. Traction Switch
920 Electrical system, Part 2 SEN03834-01 Max. traction switch Max. traction switch 2-lever type (if equipped) 1. Switch A (white wiring harness) Function 2. Switch B (yellow wiring harness) These switches are installed on the knob of the 3. Spring work equipment (lift arm) control lever.
Page 366: Sensor
920 Electrical system, Part 2 SEN03834-01 Sensor Sensor Speed sensor 1. Hall IC 5. Heat shrink tube 2. Circuit board 6. Protective tube 3. O-ring 7. Lead wire 4. Housing 8. Connector Function The speed sensor is installed on the transfer case. It generates two different types of pulses depending on the rotational direction and speed of the gear.
Page 367 920 Electrical system, Part 2 SEN03834-01 Sensor HST oil temperature sensor Brake oil temperature sensor 1. Connector 2. Plug 3. Thermistor Function The HST oil temperature sensor and the brake oil temperature sensor are installed on the motor 2 hydraulic piping and front axle, respectively. They generate the signal for the change in temperature as variation in the resistance of the thermistor.
Page 368 920 Electrical system, Part 2 SEN03834-01 Sensor HST oil filter clogging sensor 1. Terminal 2. Plug Function This sensor is installed on the HST oil filter to monitor the oil pressure before and after the filter. If the pressure goes beyond the specified level, the switch is set to "ON". Coolant level sensor 1.
Page 369 920 Electrical system, Part 2 SEN03834-01 Sensor Fuel level sensor 1. Connector 4. Body 7. Spacer 2. Float 5. Spring 3. Arm 6. Contact Function This sensor is installed on the side face of the fuel tank. The float moves up and down according to the fuel level.
Page 370 920 Electrical system, Part 2 SEN03834-01 Sensor Accelerator pedal sensor 1. Pedal Output characteristics 2. Connector 3. Sensor Function This sensor is installed on the surface of the floor. It outputs the accelerator signal or idle validation signal depending on the accelerator pedal pressing angle.
Page 371 920 Electrical system, Part 2 SEN03834-01 Sensor Water-in-fuel sensor 1. Connector 3. Sensor 2. Tube 4. O-ring Function This sensor is installed in the cup of the fuel pre-filter. It outputs the signal as entrainment of water in fuel is sensed. Boom kick-out proximity switch Bucket positioner proximity switch 1.
Page 372 920 Electrical system, Part 2 SEN03834-01 Sensor WA250, 250PZ-6 10-920...
Page 373 SEN03834-01 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03834-01 ©2007 KOMATSU All Rights Reserved Printed in Japan 10-07 (01) 10-920...
Page 374: 20 Standard Value Table
SEN03835-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 20 Standard value table 100 Standard service value table Standard service value table for engine ......................2 Standard service value table for chassis......................3...
Page 375: Standard Service Value Table For Engine
100 Standard service value table SEN03835-00 Standard service value table for engine Standard service value table Standard service value table for engine Machine model WA250-6 Engine SAA6D107E-1 Standard value for Item Measurement conditions Unit Service limit value new machine High idle (*)
Page 376: Standard Service Value Table For Chassis
100 Standard service value table SEN03835-00 Standard service value table for chassis Standard service value table for chassis Machine model WA250-6 Standard value for Item Measurement conditions Unit Service limit value new machine 5.9 (+5.9/0) N – 13.7 {1.4} FORWARD {0.6 (+0.6/0)}...
Page 377 100 Standard service value table SEN03835-00 Standard service value table for chassis Machine model WA250-6 Standard value for Item Measurement conditions Unit Service limit value new machine • Engine stopped Play 20 ± 20 Max. 60 • Machine facing straight to front •...
Page 378 100 Standard service value table SEN03835-00 Standard service value table for chassis Machine model WA250-6 Standard value for Item Measurement conditions Unit Service limit value new machine 4 ± 0.2 4 ± 0.3 13 ± 0.7 13 ± 0.9 Travel speed...
Page 379 100 Standard service value table SEN03835-00 Standard service value table for chassis Machine model WA250-6 Standard value for Item Measurement conditions Unit Service limit value new machine • Tire inflation pressure: Specified pres- sure • Flat paved road with 1/5 (11°20') grade Performance —...
Page 380 100 Standard service value table SEN03835-00 Standard service value table for chassis Machine posture and procedure for performance measurement Fig. A Fig. D Fig. B Fig. E Fig. C Fig. F WA250, 250PZ-6 20-100...
Page 381 100 Standard service value table SEN03835-00 Standard service value table for chassis Fig. G Fig. H Fig. J 20-100 WA250, 250PZ-6...
Page 382 100 Standard service value table SEN03835-00 Standard service value table for chassis WA250, 250PZ-6 20-100...
Page 383 SEN03835-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03835-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 20-100...
Page 384: Testing And Adjusting 110 Testing And Adjusting, Part
SEN03836-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 30 Testing and adjusting 110 Testing and adjusting, Part 1 Tools for testing, adjusting, and troubleshooting..................... 4 Sketches of special tools ..........................9 Measuring engine speed..........................
Page 385 110 Testing and adjusting, Part 1 SEN03836-01 Replacing alternator belt ..........................36 30-110 WA250, 250PZ-6...
Page 386 110 Testing and adjusting, Part 1 SEN03836-01 30-110 WA250, 250PZ-6...
Page 387: Tools For Testing, Adjusting, And Troubleshooting
110 Testing and adjusting, Part 1 SEN03836-01 Tools for testing, adjusting, and troubleshooting Tools for testing, adjusting, and troubleshooting Testing and Sym- Q'ty Part No. Part Name Remarks adjusting item 799-201-9001 Handy smoke checker Bosch index: Level 0 – 9 Measuring exhaust gas Commercially color...
Page 388 110 Testing and adjusting, Part 1 SEN03836-01 Tools for testing, adjusting, and troubleshooting Testing and Sym- Q'ty Part No. Part Name Remarks adjusting item Pressure gauge: 2.5, 6, 40, 60 MPa 799-101-5002 Analog hydraulic tester {25, 60, 400, 600 kg/cm Testing clutch control 790-261-1204 Digital hydraulic tester Pressure gauge: 60 MPa {600 kg/cm...
Page 389 110 Testing and adjusting, Part 1 SEN03836-01 Tools for testing, adjusting, and troubleshooting Testing and Sym- Q'ty Part No. Part Name Remarks adjusting item 799-601-7400 T-adapter assembly AMP040 Connector 799-601-7500 T-adapter assembly AMP070 Connector 799-601-9000 T-adapter assembly DT, HD30 Connector 799-601-9300 T-adapter assembly DRC26-40 (5 pins) 799-601-7360 Adapter...
Page 390 110 Testing and adjusting, Part 1 SEN03836-01 Tools for testing, adjusting, and troubleshooting Testing and Sym- Q'ty Part No. Part Name Remarks adjusting item 799-601-7060 • Adapter for SWP For SWP8P (Excl. 799-601-8000) For M1P (Excl. 799-601-7000 and 799-601-7080 • Adapter for M 799-601-7100) 799-601-7090 •...
Page 391 110 Testing and adjusting, Part 1 SEN03836-01 Tools for testing, adjusting, and troubleshooting Testing and Sym- Q'ty Part No. Part Name Remarks adjusting item Measuring voltage and Commercially — Tester resistance available Removal and installation Commercially 3.26 mm TORX wrench of boost pressure and —...
Page 392: Sketches Of Special Tools
110 Testing and adjusting, Part 1 SEN03836-01 Sketches of special tools Sketches of special tools Note: Komatsu cannot accept any responsibility for special tools manufactured according to these sketches. Socket WA250, 250PZ-6 30-110...
Page 393: Measuring Engine Speed
110 Testing and adjusting, Part 1 SEN03836-01 Measuring engine speed Measuring engine speed Measuring HST stall speed Referring to “Special function of machine Put chocks under the tires securely. monitor”, select the real time monitoring When measuring, check that there are no function of the service mode.
Page 394 110 Testing and adjusting, Part 1 SEN03836-01 Measuring engine speed Measuring hydraulic stall speed Measuring HST stall and hydraulic stall (full Referring to “Special function of machine stall) speed monitor”, select the real time monitoring Set the machine monitor as in “2. Measur- function of the service mode.
Page 395: Measuring Exhaust Gas Color
110 Testing and adjusting, Part 1 SEN03836-01 Measuring exhaust gas color Measuring exhaust gas color Measuring with smoke meter A2 Insert the probe of smoke meter A2 in the a Necessary tools outlet of the muffler (exhaust pipe) and fix it to the exhaust pipe with a clip.
Page 396 110 Testing and adjusting, Part 1 SEN03836-01 Measuring exhaust gas color Start the engine and keep it running until the engine coolant temperature rises to the operating range. Accelerate the engine suddenly or run it at high idle and press the accelerator pedal o f s m o k e m e t e r A 2 a n d c o l l e c t t h e exhaust gas into the filter paper.
Page 397: Adjusting Valve Clearance
110 Testing and adjusting, Part 1 SEN03836-01 Adjusting valve clearance Adjusting valve clearance Rotate the crankshaft forward (clockwise, see- ing from the fan) with gear B1 and set wide slit a Necessary tools (b) of the rotation sensor ring to projection top (a) of front cover.
Page 398 110 Testing and adjusting, Part 1 SEN03836-01 Adjusting valve clearance Adjust the valve clearance according to the fol- lowing procedure. While fixing adjustment screw (10), loosen locknut (11). Insert clearance gauge clearance between rocker arm (12) and crosshead (13) and adjust the valve clearance with adjustment screw (10).
Page 399: Measuring Compression Pressure
110 Testing and adjusting, Part 1 SEN03836-01 Measuring compression pressure Measuring compression pressure Loosen injector terminal nut (4) and remove the terminal from the injector. a Necessary tools Set the cylinder to be checked to the compres- Symbol Part No. Part Name sion top dead center.
Page 400 110 Testing and adjusting, Part 1 SEN03836-01 Measuring compression pressure 16. Rotate the engine with the starting motor and measure the compression pressure. a Read the gauge when its pointer is stabi- lized. 17. After finishing measurement, remove the mea- suring tools and return the removed parts.
Page 401 110 Testing and adjusting, Part 1 SEN03836-01 Measuring compression pressure Permanently tighten retainer (6) of fuel inlet connector (7). Retainer: 50 ± 5 Nm {5.1 ± 0.51 kgm} Tighten the sleeve nut of the fuel high- pressure tube on the head side and then tighten that on the common rail side.
Page 402: Measuring Blow-By Pressure
110 Testing and adjusting, Part 1 SEN03836-01 Measuring blow-by pressure Measuring blow-by pressure While pressing the brake pedal, set the direc- tional lever or switch to the F (forward) or R a Necessary tools (reverse) position. Keep pressing the brake pedal securely. Symbol Part No.
Page 403: Measuring Engine Oil Pressure
110 Testing and adjusting, Part 1 SEN03836-01 Measuring engine oil pressure Measuring engine oil pressure Start the engine and heighten the coolant tem- perature to the operating range. a Necessary tools While running the engine at low idle and high Symbol Part No.
Page 404: Measuring Intake Air (Boost) Pressure
110 Testing and adjusting, Part 1 SEN03836-01 Measuring intake air (boost) pressure Measuring intake air (boost) Measurement with measuring tool Open the engine right side cover. pressure Remove air boost pressure pickup plug (1) a Necessary tools (R1/8). Symbol Part No. Part Name 799-101-5002 Hydraulic tester 799-201-2202 Boost gauge kit...
Page 405 110 Testing and adjusting, Part 1 SEN03836-01 Measuring intake air (boost) pressure Press the accelerator pedal gradually to the high idle. While running the engine at high idle, stall the HST and hydraulic work equipment and measure the intake air pressure (boost pressure).
Page 406: Handling Fuel System Equipment
Before the fuel circuit is tested and its parts are The fuel filter cartridge used must be a genuine removed, the residual pressure in the fuel cir- Komatsu part. cuit must be released completely. Accordingly, The fuel injection pump and nozzle of the com- observe the following.
Page 407: Measuring Fuel Pressure
110 Testing and adjusting, Part 1 SEN03836-01 Measuring fuel pressure Measuring fuel pressure Install adapter G2 and nipple [1] of hydraulic tester G1 and connect them to a Necessary tools oil pressure gauge [2]. a Use the oil pressure gauge of 2.5 Symbol Part No.
Page 408 110 Testing and adjusting, Part 1 SEN03836-01 Measuring fuel pressure Measuring pressure in fuel return circuit Measuring fuel negative-pressure circuit Remove fuel pressure pickup plug (2) pressure from the fuel return block. Remove joint bolt (2) of fuel hose (1) between the prefilter and supply pump.
Page 409: Measuring Fuel Return Rate And Leakage
110 Testing and adjusting, Part 1 SEN03836-01 Measuring fuel return rate and leakage Measuring fuel return rate and leakage a Necessary tools Symbol Part No. Part name 795-790-4700 Tester kit 795-790-6700 Adapter 6754-71-5340 Connector 6754-71-5350 Washer Commercially Measuring cylinder available Commercially Stopwatch available...
Page 410 110 Testing and adjusting, Part 1 SEN03836-01 Measuring fuel return rate and leakage Measuring return rate from supply pump Run the engine at low idle and measure Open the engine right side cover. the return rate in 25 seconds with measur- Disconnect return hose (1) of the supply ing cylinder H4.
Page 411 110 Testing and adjusting, Part 1 SEN03836-01 Measuring fuel return rate and leakage Measuring leakage from pressure limiter Open the engine right side cover. Disconnect return hose (2) from the pres- sure limiter. a Install the seal washer to the connec- tor bolt.
Page 412 110 Testing and adjusting, Part 1 SEN03836-01 Measuring fuel return rate and leakage Install connector bolt [3] of adapter H2 instead of the removed connector bolt and connect test hose [4]. a Lay the test hose so that it will not slacken and put its end in the receiv- ing pan.
Page 413: Bleeding Air From Fuel Circuit
110 Testing and adjusting, Part 1 SEN03836-01 Bleeding air from fuel circuit Bleeding air from fuel circuit a If fuel is used up or if a fuel circuit part is removed and installed, bleed air from the fuel circuit according to the following procedure. Put chocks under the tires securely.
Page 414: Testing Leakage In Fuel System
110 Testing and adjusting, Part 1 SEN03836-01 Testing leakage in fuel system Testing leakage in fuel system Inspect the fuel piping and devices for fuel leakage. Very high pressure is generated in the high- a Check mainly around the high-pressure pressure circuit of the fuel system.
Page 415: Handling Reduced Cylinder Mode Operation
110 Testing and adjusting, Part 1 SEN03836-01 Handling reduced cylinder mode operation Handling reduced cylinder mode Handling no-injection cranking operation operation a Reduced cylinder mode operation means to a No-injection cranking means to crank the run the engine with the fuel injectors of 1 or engine with the starting motor while all the more cylinders disabled electrically to reduce injections are stopped electrically.
Page 416: Handling Controller Voltage Circuit
110 Testing and adjusting, Part 1 SEN03836-01 Handling controller voltage circuit Handling controller voltage circuit Check of muffler and muffler stack for looseness and damage When disconnecting or connecting a connector between the engine controller and engine, be Check the muffler and muffler stack visually for sure to turn the starting switch OFF.
Page 417: Check Of Muffler Function
110 Testing and adjusting, Part 1 SEN03836-01 Check of muffler function Check of muffler function Check of installed condition of cylinder head and manifolds Check the muffler for abnormal sound and dif- ference in sound from a new machine. If it Check the installed condition of the cylinder head makes abnormal sound, repair it, referring to and air intake manifold and exhaust manifold.
Page 418: Check Of Engine Piping For Damage And Looseness
110 Testing and adjusting, Part 1 SEN03836-01 Check of engine piping for damage and looseness Check of engine piping for Testing and adjusting air condi- damage and looseness tioner compressor belt tension Air intake and exhaust systems: Testing Check the piping for damage, looseness of the Press the middle point between air conditioner mounting bolts and nuts, and suction of air and compressor pulley and drive pulley with a finger...
Page 419: Replacing Alternator Belt
110 Testing and adjusting, Part 1 SEN03836-01 Replacing alternator belt Replacing alternator belt a The auto-tensioner is provided for the alterna- tor belt. Thus, testing and adjustment of the belt is usually no necessary. a Remove air conditioner compressor belt before replacing the alternator belt.
Page 420 110 Testing and adjusting, Part 1 SEN03836-01 Replacing alternator belt WA250, 250PZ-6 30-110...
Page 421 SEN03836-01 WA250-6, WA250PZ-6 Wheel loader Form No. SEN03836-01 ©2009 KOMATSU All Rights Reserved Printed in Japan 06-09 30-110...
Page 422: Testing And Adjusting, Part
SEN03837-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 30 Testing and adjusting 120 Testing and adjusting, Part 2 Checking operating force of accelerator pedal ....................3 Checking directional lever..........................4 Testing and adjusting HST oil pressure ......................5 Testing clutch control pressure ........................
Page 423 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting bucket positioner ......................36 Testing and adjusting of boom kick-out switch ....................37 Checking proximity switch operation pilot lamp .................... 38 Procedure for testing diodes ......................... 39 Preparation work for troubleshooting for electric system ................41 Starting KOMTRAX terminal operations......................
Page 424: Checking Operating Force Of Accelerator Pedal
120 Testing and adjusting, Part 2 SEN03837-01 Checking operating force of accelerator pedal Checking operating force of a After greasing, wipe off grease completely (No grease is adhered on roller surface and roller accelerator pedal sliding surface). Necessary tools Symbol Part No.
Page 425: Checking Directional Lever
120 Testing and adjusting, Part 2 SEN03837-01 Checking directional lever Checking directional lever Necessary tools Symbol Part No. Part Name 79A-264-0021 Push-pull scale Commercially Scale available Stop the machine on a level ground, lower the work equipment to the ground, and set chocks under the tire securely.
Page 426: Testing And Adjusting Hst Oil Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting HST oil pressure Testing and adjusting HST oil pressure Necessary tools Symbol Part No. Part Name 799-101-5002 Analog type hydraulic tester 790-261-1204 Digital type hydraulic tester Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank.
Page 427 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting HST oil pressure Testing low-pressure relief pressure (basic pressure of work equipment PPC circuit) [Testing with monitoring function] See “Testing high-pressure cut-off oil pressure”. [Testing with tools] Remove low-pressure relief pressure mea- surement plug (4) (10 mm, P = 1.25 mm) from under the machine.
Page 428 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting HST oil pressure Testing servo piston actuating pressure Adjusting Remove servo piston actuation pressure mea- surement plug (7) or (8) (G 1/4) (width across a The high-pressure relief pressure is also the flats for hexagonal head wrench: 8 mm).
Page 429 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting HST oil pressure Adjusting low-pressure relief valve Adjusting DA valve a If the low-pressure relief pressure is not cor- a If the servo piston control pressure is not cor- rect, adjust the low-pressure relief valve as fol- rect, adjust the DA valve as follows.
Page 430: Testing Clutch Control Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing clutch control pressure Testing clutch control pressure Necessary tools Symbol Part No. Part Name 799-101-5002 Analog type hydraulic tester 790-261-1204 Digital type hydraulic tester 799-401-3100 Adapter 02896-11008 O-ring When removing the measurement plug and disconnecting the hose, loosen the oil filler cap slowly to release the pressure inside the hydraulic tank.
Page 431: Testing And Adjusting Steering Wheel
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting steering wheel Testing and adjusting steering Measuring operating force of steering wheel wheel a Measurement conditions Necessary tools Road surface: Flat, horizontal, dry paved surface Symbol Part No. Part Name Engine coolant temperature: 79A-264-0021 Push-pull scale...
Page 432 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting steering wheel Measuring operating time for steering wheel a Measurement conditions Road surface: Flat, horizontal, dry paved surface Engine coolant temperature: Within green range on engine coolant temperature gauge Hydraulic oil temperature: 45 –...
Page 433: Testing And Adjusting Steering Oil Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting steering oil pressure Testing and adjusting steering oil Fit a nipple P [3] to the steering circuit pressure measurement plug hole, then install oil pres- pressure sure gauge P [1], P [2] (40 MPa {400 kg/cm Necessary tools Symbol Part No.
Page 434 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting steering oil pressure Adjusting main relief pressure Loosen lock screw (5), and then turn adjust- ment screw (6) to adjust. Stop the engine. a Turn the adjustment screw to adjust as fol- Remove cover (1) at the lower right of the lows.
Page 435: Bleeding Air From Steering Circuit
120 Testing and adjusting, Part 2 SEN03837-01 Bleeding air from steering circuit Bleeding air from steering circuit a Bleed the air from the circuit as follows if the steering valve or steering cylinder have been removed and installed again. Start the engine and run at idle for approx. 5 minutes.
Page 436: Testing Hydraulic Fan
120 Testing and adjusting, Part 2 SEN03837-01 Testing hydraulic fan Testing hydraulic fan Connect the cable of probe [2] to tachometer [4]. Necessary tools Tachometer kit Q1 Symbol Part No. Part Name 799-205-1100 Tachometer KIT 799-101-5002 Analog type hydraulic tester 790-261-1204 Digital type hydraulic tester 799-401-3300...
Page 437 120 Testing and adjusting, Part 2 SEN03837-01 Testing hydraulic fan Testing fan drive oil pressure Open the radiator grill. Disconnect hose (1), install oil pressure gauge Q2 (40 MPa {400 kg/cm }) and adapter Q3 (Hose size: For #04), and connect hose (1) again.
Page 438: Measuring Brake Pedal
120 Testing and adjusting, Part 2 SEN03837-01 Measuring brake pedal Measuring brake pedal a Measurement conditions Engine coolant temperature: Within green range on engine coolant temperature gauge Engine speed: Low idle Install push gauge [1] to the operator's foot. a Set the push gauge at a point 150 mm from the fulcrum of the pedal.
Page 439: Testing And Adjusting Brake Pedal Linkage
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting brake pedal linkage Testing and adjusting brake pedal linkage Testing Check for play in linkage mounting pin (7), pin- hole of lever (6), and lever bushing. Measure length of link (1), and check that it is within the standard value.
Page 440: Measuring Brake Performance
120 Testing and adjusting, Part 2 SEN03837-01 Measuring brake performance Measuring brake performance 9JF01100 a Measurement conditions Road surface: Flat, horizontal, dry paved surface Travel speed: 35 km/h when brakes are applied Tire inflation pressure: Specified pressure Tire size: 20.5 – 25 Delay in applying brakes: 0.1 sec Specified operating force:...
Page 441: Testing And Adjusting Accumulator Charge Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting accumulator charge pressure Testing and adjusting accumulator charge pressure Necessary tools Symbol Part No. Part Name 799-101-5002 Analog type hydraulic tester 790-261-1204 Digital type hydraulic tester Stop the machine on a level ground, lower the work equipment to the ground, and set chocks under the tire securely.
Page 442 120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting accumulator charge pressure Adjusting a When the accumulator charge cut-out pres- sure is adjusted, the cut-in pressure also changes in proportion to the ratio of the valve area. Loosen locknut (4) of unload relief valve (accu- mulator charge cut-out valve) (3), then turn adjustment screw (5) to adjust.
Page 443: Testing Wheel Brake Oil Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing wheel brake oil pressure Testing wheel brake oil pressure Remove brake tube (2) of the measured side. a The right side is shown as an example in a Necessary tools the figure. Symbol Part No.
Page 444 120 Testing and adjusting, Part 2 SEN03837-01 Testing wheel brake oil pressure Composition and connection diagram of brake test kit S WA250, 250PZ-6 30-120...
Page 445 120 Testing and adjusting, Part 2 SEN03837-01 Testing wheel brake oil pressure Tighten bleeder screw (4), operate pump S3 to increase the pressure to 4.1 MPa {42 kg/cm and tighten stop valve [2] (a component part of S1). Leave the brake circuit pressurized for 5 min- utes and check lowering of the pressure.
Page 446: Testing Wear Of Brake Disc
120 Testing and adjusting, Part 2 SEN03837-01 Testing wear of brake disc Testing wear of brake disc While pressing the brake pedal, insert testing gauge U in the inspection plug hole and pinch Necessary tools the inspection projection around piston (2) and plate (3) with the inspection gauge tip.
Page 447: Bleeding Air From Wheel Brake Circuit
120 Testing and adjusting, Part 2 SEN03837-01 Bleeding air from wheel brake circuit Bleeding air from wheel brake Connect hose [1] to bleeder screw (2) and place hose [1] in the oil receive pan. circuit a Work on the rear side similarly from under- Necessary tools side of the machine.
Page 448: Releasing Residual Pressure In Brake Accumulator Circuit
120 Testing and adjusting, Part 2 SEN03837-01 Releasing residual pressure in brake accumulator circuit Releasing residual pressure in brake accumulator circuit Before disconnecting any of the following brake accumulator circuits, release resid- ual pressure in that brake circuits. Piping between accumulator charge valve and brake accumulator Piping between brake accumulator and brake valve on both sides...
Page 449: Testing Parking Brake Performance
120 Testing and adjusting, Part 2 SEN03837-01 Testing parking brake performance Testing parking brake performance a Measurement condition Tire inflation pressure: Specified pressure Road: 1/5 gradient (11° 20'), flat, and dry road Machine: Ready for operation Measuring method Start the engine and set the machine in the straight travel position, and then drive up a slope of 1/5 gradient with no load in the bucket.
Page 450: Testing And Adjusting Parking Brake Control Cable
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting parking brake control cable Testing and adjusting parking Adjusting brake control cable Release the parking brake. a Check that the pawl of the parking brake Necessary tools lever is at the lowest position. Symbol Part No.
Page 451: Measuring And Adjusting Work Equipment Control Lever
120 Testing and adjusting, Part 2 SEN03837-01 Measuring and adjusting work equipment control lever Measuring and adjusting work Measuring travel of work equipment control equipment control lever lever Measure the travel at each position when operating Necessary tools the work equipment control lever. Symbol Part No.
Page 452: Testing And Adjusting Work Equipment Hydraulic Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting work equipment hydraulic pressure Testing and adjusting work Adjusting equipment hydraulic pressure a Always stop the engine before adjusting the oil Necessary tools pressure. When carrying out the operation with the Symbol Part No.
Page 453: Testing Work Equipment Ppc Oil Pressure
120 Testing and adjusting, Part 2 SEN03837-01 Testing work equipment PPC oil pressure Testing work equipment PPC oil pressure Necessary tools Symbol Part No. Part Name 799-101-5002 Analog type hydraulic tester 790-261-1204 Digital type hydraulic tester 793-463-1100 Stopper Loosen the oil filler cap slowly to release the pressure inside the hydraulic tank.
Page 454 120 Testing and adjusting, Part 2 SEN03837-01 Testing work equipment PPC oil pressure Operate the work equipment control lever at high idle and measure the oil pressure. a A: Bucket TILT B: Bucket DUMP C: Lift arm RAISE D: Lift arm LOWER After finishing the work, remove the measuring instruments and return the removed parts.
Page 455: Bleeding Air From Hydraulic Circuit
120 Testing and adjusting, Part 2 SEN03837-01 Bleeding air from hydraulic circuit Bleeding air from hydraulic circuit Bleeding air from work equipment PPC circuit Operate each work equipment lever fully and hold it in position to relieve the circuit for approx.
Page 456: Releasing Remaining Pressure In Hydraulic Circuit
120 Testing and adjusting, Part 2 SEN03837-01 Releasing remaining pressure in hydraulic circuit Releasing remaining pressure in hydraulic circuit Releasing remaining pressure between each hydraulic cylinder and control valve a If the piping between the hydraulic cylinder and the control valve is to be disconnected, release the remaining pressure from the circuit as fol- lows.
Page 457: Testing And Adjusting Bucket Positioner
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting bucket positioner Testing and adjusting bucket Adjust and secure clearance (a) between the sensitive surface of proximity switch positioner (1) and detection bar (2) to the standard a Measuring condition range with the shim and mounting bolt of Engine coolant temperature: White range the proximity switch bracket.
Page 458: Testing And Adjusting Of Boom Kick-Out Switch
120 Testing and adjusting, Part 2 SEN03837-01 Testing and adjusting of boom kick-out switch Testing and adjusting of boom Adjust the switch so that clearance (a) between the sensing surface of the switch and plate (2) kick-out switch is the standard value, then secure in position. Testing Switch mounting nut: 14.7 –...
Page 459: Checking Proximity Switch Operation Pilot Lamp
120 Testing and adjusting, Part 2 SEN03837-01 Checking proximity switch operation pilot lamp Checking proximity switch operation pilot lamp The proximity switch has a pilot lamp to indicate its operating condition. Use this pilot lamp when adjusting the proximity switch. A: Operation pilot lamp (Red) Positional relationship between sensitive surface Proximity switch...
Page 460: Procedure For Testing Diodes
120 Testing and adjusting, Part 2 SEN03837-01 Procedure for testing diodes Procedure for testing diodes When using digital type circuit tester Switch the testing mode to diode range a Check an assembled-type diode (8 pins) and and confirm the indicated value. independent diode (2 pins) in the following a Voltage of the battery inside is dis- manner.
Page 461 120 Testing and adjusting, Part 2 SEN03837-01 Procedure for testing diodes When using analog type circuit tester Switch the testing mode to resistance range. Apply the leads of the tester as explained below and check the movement of the pointer. Put the red probe (+) of the test lead to the anode (P) and the black probe (–) to the cathode (N) of diode.
Page 462: Preparation Work For Troubleshooting For Electric System
120 Testing and adjusting, Part 2 SEN03837-01 Preparation work for troubleshooting for electric system Preparation work for troubleshooting for electric system a When carrying out troubleshooting for an elec- tric circuit related to the machine monitor, transmission controller, work equipment con- troller, or KOMTRAX terminal, expose the related connectors according to the following procedure.
Page 463 120 Testing and adjusting, Part 2 SEN03837-01 Preparation work for troubleshooting for electric system Connect diagnosis T-adapters to connec- KOMTRAX terminal tors L24 to L30 of machine monitor (2). Open right door (1) and remove console cover (2). HST controller Remove cover (1) from the rear of the cab.
Page 464 120 Testing and adjusting, Part 2 SEN03837-01 Preparation work for troubleshooting for electric system Boost pressure and temperature sensor Common rail pressure sensor (FUEL RAIL (BOOST PRESS & IMT) PRESS) a Disconnection and connection of connector a Disconnection and connection of connector The connector of the boost pressure and The connector of the common rail pres- temperature sensor has a special locking...
Page 465 120 Testing and adjusting, Part 2 SEN03837-01 Preparation work for troubleshooting for electric system a Precautions for connecting connector Ambient pressure sensor (AMBAIR PRES- Take care not to connect the connector SURE) reversely. Engine Ne speed sensor (CRANK SENSOR) Engage lock (e) on the wiring harness Engine Bkup speed sensor (CAM SENSOR) side with triangular notch (f) on the sensor Engine oil pressure switch (OIL PRESSURE...
Page 466: Starting Komtrax Terminal Operations
120 Testing and adjusting, Part 2 SEN03837-01 Starting KOMTRAX terminal operations Starting KOMTRAX terminal When about 3 to 5 seconds elapsed after the starting switch was set to ACC, make operations sure that the 7-segment indicator lamp In the case where the KOMTRAX terminal has changes to hyphen “–”...
Page 467 120 Testing and adjusting, Part 2 SEN03837-01 Starting KOMTRAX terminal operations Make sure that the 7-segment indicator a As [Normal] is indicated, proceed to l a m p i s i n d i c a t e d n o r m a l l y o n t h e the next step.
Page 468 120 Testing and adjusting, Part 2 SEN03837-01 Starting KOMTRAX terminal operations a If [Network trouble] is indicated, 10) Turn the starting switch OFF. check the display of [LED-C4] refer- 11) Make sure that the 7-segment indicator ring to “Lamp display of KOMTRAX lamp is displayed normally after 5 seconds terminal”.
Page 469 120 Testing and adjusting, Part 2 SEN03837-01 Starting KOMTRAX terminal operations Application for the start of use a Application for the start of use should be made only after the sign-up test is fin- ished. Notify the KOMTRAX operations adminis- trator of the following information about the machine that completed the station opening check in the machine side.
Page 470: Indicator Lamps Of Komtrax Terminal
120 Testing and adjusting, Part 2 SEN03837-01 Indicator lamps of KOMTRAX terminal Indicator lamps of KOMTRAX terminal LED lamps for CPU 7-segment and dot displays for CPU LED-C1 (State of R or ACC signal) 7 segments (Number of unsent mails) LED-C2 (Starting output state) Dot (GPS positioning state) LED-C3 (State of S-NET or C signal)
Page 471 120 Testing and adjusting, Part 2 SEN03837-01 Indicator lamps of KOMTRAX terminal In the KOMTRAX system, various information and processing details are displayed on the LED on the upper surface of the KOMTRAX terminal. Therefore, if a detect is suspected in the system, perform the following checks.
Page 472 120 Testing and adjusting, Part 2 SEN03837-01 Indicator lamps of KOMTRAX terminal Contents of 7-segment and dot displays for CPU a The LED display should be checked with the starting switch turned ON. Display Name/function Description (*2) The number indicates the number of unsent mails. (10 or more 0 to 9 unsent mails are indicated by “9”.) Light-on indicates that the displayed...
Page 473 SEN03837-01 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03837-01 ©2011 KOMATSU All Rights Reserved Printed in Japan 01-11 30-120...
Page 474: Testing And Adjusting, Part
SEN03838-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 30 Testing and adjusting 130 Testing and adjusting, Part 3 Adjusting machine monitor..........................2 Adjusting replaced, reassembled or added sensor, controller, etc. with machine monitor......3 Special functions of machine monitor (EMMS) ....................
Page 475: Adjusting Machine Monitor
130 Testing and adjusting, Part 3 SEN03838-00 Adjusting machine monitor Adjusting machine monitor Layout of rotary switches (SW1, SW2, and SW3) and DIP switches (SW5 and SW6) Do not change the setting of the rotary switches (SW1, SW2, and SW3) and DIP switches (SW5 and SW6) on the back side of the machine monitor.
Page 476: Adjusting Replaced, Reassembled Or Added Sensor, Controller, Etc. With Machine Monitor
130 Testing and adjusting, Part 3 SEN03838-00 Adjusting replaced, reassembled or added sensor, controller, etc. with machine monitor Adjusting replaced, reassembled or added sensor, controller, etc. with machine monitor Items to be set when sensor or controller is replaced, reassembled or added If any of the following components and parts is replaced or reassembled, initialize the sensors, solenoids, etc.
Page 477 130 Testing and adjusting, Part 3 SEN03838-00 Adjusting replaced, reassembled or added sensor, controller, etc. with machine monitor Adjustment for user's needs If the user makes the following indications or requests, change or adjust the items shown below with the machine monitor.
Page 478 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Special functions of machine monitor (EMMS) EMMS: Equipment Management Monitoring System Machine monitor mode change switch 1 Machine monitor mode change switch 2 Character display WA250, 250PZ-6 30-130...
Page 479: Special Functions Of Machine Monitor (Emms)
130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Normal functions and special functions of machine monitor The machine monitor is equipped with the normal functions and special functions. Various items of data are displayed on the character display in the middle of the machine monitor. Depending on the internal setting of the machine monitor, the display items are divided into automatic dis- play items and items displayed when the machine monitor switches are operated.
Page 480 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Functions and flow of service mode Note: Some items may not be used, depending on the setting and specification, although they are displayed on the monitor. (For details, see the text.) WA250, 250PZ-6 30-130...
Page 481 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 30-130 WA250, 250PZ-6...
Page 482 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) WA250, 250PZ-6 30-130...
Page 483 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Operator mode HST function selection function While the speed range selector switch is in the The operator mode is outlined below. 3rd or 4th gear speed position, the reverse For details of the operator mode, see “Struc- speed range can be set to 2 levels.
Page 484 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Maintenance monitoring function Language selection function Switch operation allows selecting a display lan- Filter, oil replacement time display (auto- matic display) guage of the machine monitor. As the filter or oil replacement time draws Functions of the service mode are con- close, the machine monitor automatically stantly displayed in English since they are...
Page 485 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Monitor brightness adjustment function Travel speed/engine speed display select- Brightness of the machine monitor is adjustable ing function in seven levels through the switch operation. A unit to be used for the machine monitor Adjustment of brightness is available in speed display is selectable from km/h and two approaches –...
Page 486 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 11. Action code display function If a trouble occurs, the machine monitor dis- plays an action code corresponding to the seri- ousness of the trouble to alert the operator for appropriate actions.
Page 487 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 12. Failure code display function The service code display function displays the following information. Pressing [>] switch once while an action is dis- played on the machine monitor displays the A: Failure code (location code + problem failure code corresponding to the failure cur- code)
Page 488 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Service mode (*1): When the cursor is located at the left- most position, pressing the switch Procedure for switching to Service mode restores the normal screen (Operator and screen display mode).
Page 489 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) [4] CYLINDER CUT-OUT: Engine Electrical system fault history display func- tion (ELECTRIC FAULT) reduced-cylinder function [5] NO INJECTION: No injection crank- The machine monitor records the past failures ing function in the electric system as the failure codes.
Page 490 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) For details of a displayed failure code, see 2-6. Deleting all fault history Press [<] or [>] switch while the fault his- “Failure code list” of the failure code dis- play function.
Page 491 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Mechanical system fault history display 3-3. Displayed fault history The mechanical system fault history display function (MACHINE FAULT) The machine monitor records the past failures function displays the following information. in the mechanical system as the failure codes.
Page 492 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Failure codes table Failure Action Category of Troubled part/item Trouble Controller code record code Mechanical 2G40ZG Brake Oil pressure reduction system Mechanical 6091NX HST filter Clogging system Mechanical 989FN1 Travel speed...
Page 493 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Failure Action Category of Troubled part/item Trouble Controller code code record Mechanical CA234 Engine Overspeed system Electrical CA238 Ne speed sensor power supply Abnormality system Electrical CA271 IMV (IMA) Short circuit system...
Page 494 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Failure Action Category of Troubled part/item Trouble Controller code code record Electrical CA553 Common rail pressure Abnormally high pressure 1 system Electrical CA559 Supply pump Low rail pressure 1 system Electrical CA689...
Page 495 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Failure Action Category of Troubled part/item Trouble Controller code code record Electrical DAJ2KK Controller solenoid power supply Low voltage system HST controller load power supply Electrical DAJ2L3 Hot short holding line system...
Page 496 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Failure Action Category of Troubled part/item Trouble Controller code code record Electrical DGR2KB Brake oil temperature sensor Ground fault system Electrical DGR2KZ Brake oil temperature sensor Disconnection/Hot short system Electrical DHH1KX HST oil pressure sensor...
Page 497 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Failure Action Category of Troubled part/item Trouble Controller code code record Electrical DXH8KB Forward solenoid Ground fault system Electrical DXH8KZ Forward solenoid Disconnection/Ground fault system Mechanical J141N1 Steering pump Overrun alarm system...
Page 498 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Real-time monitoring function 4-3. Selecting sub menu Press [<] or [>] switch from the sub menu (REAL-TIME MONITOR) The machine monitor checks state of the screen to display the sub menus endlessly machine on real-time basis referencing signals in the following order.
Page 499 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Press [<] or [>] switch to select a monitor- 4-5. Setting 2 items simultaneous monitoring Select 2 ITEMS from the sub menu ing item. The monitoring items are scrolled accord- screen.
Page 500 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) As both monitoring codes are settled, the 2 ITEMS screen will be turned on. Holding and cancelling the monitoring data: Pressing [U] switch while the monitoring is in progress holds the monitoring data and [U] mark starts flashing.Pressing [U] switch again restores the active state.
Page 501 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Real-time monitoring codes table Use this page in next page and a spread. MONITOR PANEL [Machine monitor system] Monitoring item Displayed item Data display range Monitoring code (*1) (*2) (*3)
Page 502 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in front page and spread. MONITOR PANEL [Machine monitor system] Unit Contents of display in normal state Remarks (*4) Condition As per software No. 3rd –...
Page 503 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in next page and a spread. MONITOR PANEL [Machine monitor system] Monitoring item Displayed item Data display range Monitoring code (*1) (*2) (*3) 40500 Boom head pressure BOOM HEAD PRES -----...
Page 504 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in front page and spread. MONITOR PANEL [Machine monitor system] Unit Contents of display in normal state Remarks (*4) ----- ----- a No use these items. ----- ----- Condition...
Page 505 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) MONITOR PANEL [Machine monitor system] Monitoring Input/Output Displayed item Contents of ON/OFF switch code signal D-IN-0 Headlamp Headlamp lighting = ON (24 V)/OFF (OPEN) D-IN-1 Cooling fan reverse switch Switch = ON (24 V)/OFF (OPEN) D-IN-2 Starting switch C...
Page 506 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) MONITOR PANEL [Machine monitor system] Monitoring Input/Output Displayed item Contents of ON/OFF switch code signal D-IN-32 — — D-IN-33 — — D-IN-34 High beam (Dimmer switch) High beam = ON (GND)/OFF (OPEN) Omission of applying parking brake D-IN-35 Resetting parking brake = ON (GND)/OFF (OPEN)
Page 507 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in next page and a spread. HST [HST controller system] Monitoring Real-time monitoring item Displayed item Data display range code (*1) (*2) (*3) 20201 Software No.
Page 508 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in front page and spread. HST [HST controller system] Unit Contents of display in normal state Remarks (*4) As per software No. Condition display As per software application version No.
Page 509 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in next page and a spread. HST [HST controller system] Monitoring Real-time monitoring item Displayed item Data display range code (*1) (*2) (*3) 99100 Parking brake switch signal PARKING A/B 11/00/10/01...
Page 510 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Use this page in front page and spread. HST [HST controller system] Unit Contents of display in normal state Remarks (*4) Parking brake position (High): 00 (Middle): 10 Condition display (Low): 11 0 –...
Page 511 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) HST [HST controller system] Monitoring Input/Output Displayed item Contents of ON/OFF switch codes signal D-IN-0 FNR (Directional) lever F (Forward) F (Forward) = ON (24 V)/OFF (OPEN) D-IN-1 FNR (Directional) lever N (Neutral) N (Neutral) = ON (24 V)/OFF (OPEN)
Page 512 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) ENG [Engine controller system] Monitoring Monitoring items Displayed items Data display range Unit Remarks code (*1) (*2) (*3) (*4) Status 20400 Hardware serial No. ECM S/N Arabic numerals display 03200 Battery voltage...
Page 513 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Engine reduced-cylinder function (CYLIN- Selecting a cylinder to be reduced Using [<] or [>] switch, select a cylinder to DER CUT-OUT) The engine reduced-cylinder function denotes be reduced from No. 1 – No. 6 cylinders setting the injector of a single cylinder or two or and then settle the selected cylinder using more cylinders to electrically no injection state...
Page 514 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Cancelling a reduced cylinder Pressing [U] switch sets up the no injec- tion cranking. Using [<] or [>] switch, select the currently stop ped cylinde r an d then p re ss [U] If this screen does not appear as [U] switch to cancel the reduced-cylinder switch is hit, a communication error should...
Page 515 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Adjustment function (TUNING) 7-1. Adjustment of interval of fan automatic reverse operation The machine monitor implements initial setting after disassembly or replacement of the trans- This function is used to change the inter- fer, or after replacement or addition of sensor, val of the forward and reverse operations HST pump, HST motor and EPC valve or con-...
Page 516 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) With the [<] and [>] switches, select 03: 7-2. Adjustment of continuance of fan automatic reverse operation FAN REV PD screen. This function is used to change the contin- uance of the reverse operation when the f a n a u t o m a t i c r e v e r s e o p e r a t i o n i s selected.
Page 517 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) With the [<] and [>] switches, select 04: 7-5. Adjustment of ECSS operation travel speed (if equipped) FAN REV PD screen. This function is used to adjust the ECSS operation/reset travel speed.
Page 518 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Select “07: ECSS SPEED” with [<] or [>] Maintenance monitoring function The maintenance function offers the following switch. capabilities in the maintenance of filters and oils. Change of maintenance interval time Selection between enabling or disabling timer by item Setting of a default value...
Page 519 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) List of maintenance items Indication of items on the Replacement Item ID No. character display interval time (H) Engine oil ENG OIL Engine oil filter ENG FILT Fuel pre-filter FUEL P FILT Fuel filter...
Page 520 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Select “YES” or “NO” using [<] or [>] When “Timer by item” is disabled, the order of display becomes OFF o ON. switch. The selected cursor will start flashing. If The default display is ON.
Page 521 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Select “YES” or “NO” using [<] or [>] Press [U] switch from this state. Select “YES” or “NO” using [<] or [>] switch. switch. The selected cursor will start flashing. If The selected cursor will start flashing.
Page 522 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Using [<] or [>] switch, select the ALL Press [U] switch from the ALL ITEMS o OFF screen or the ALL ITEMS o ON ITEMS OFF OR ON screen from the fol- lowing table.
Page 523 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) As the timer stop for all items is executed: Using [<] or [>] switch, select the item to be displayed from 1] – 4] on the fuel con- The timer function for all items is stopped a n d t h e M A I N TE N A N C E M O N I TOR sumption ratio and average fuel consump-...
Page 524 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Cumulative fuel consumption and Deleting display data elapsed time Data on screens 5) – 8) allow deletion. The upper column displays the cumu- Select a desired item and then delete it lative fuel consumption [L] from the using [U] switch.
Page 525 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Pressing [U] switch displays the cor- rection screen. Default value: 0.0% This setting allows correcting the cumulative fuel consumption in the range of –50.0 to +50.0. Move the cursor to [+] or [–]. Pressing [<] or [>] switch alternately displays [+] and [–].
Page 526 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 10. OPTIONAL SELECT function The procedure for setting an option is as follows; Set the option and turn the starting switch OFF. After the power for each controller is turned OFF (about 15 seconds), turn the starting switch ON again, and the option is effective.
Page 527 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) *4: Fixed to speedometer. *5: Setting at previous ADD or initial setting. *6: “Travel speed/rpm on character display: Displayed/Not displayed” is displayed in operator mode. *7: “Travel speed/rpm on character display: Displayed/Not displayed” is not displayed in operator mode. *8: Not displayed.
Page 528 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) Display the OPTIONAL SELECT screen 10-1. Option setting/not setting selection Among the items included in the list of installed from the menu screen of Service mode. optional devices and their setting, the option setting/not setting selection applies to the fol- lowing items.
Page 529 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 10-2. Selection of optional tire type 10-4. Setting tire deflection option Select 9: TIRE SIZE from the list of installed Select “1: TIRE TYPE” from “Optional device installation setting table”.
Page 530 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 10-6. Storing option selection 11. Machine serial number input function Display the MACHINE No. SET screen When the option selection was changed, turn off the starting switch once to stop the from the menu screen of Service mode.
Page 531 130 Testing and adjusting, Part 3 SEN03838-00 Special functions of machine monitor (EMMS) 12. Machine model select function With the [<] and [>] switches, select the machine model. (MACHINE WA***) The setting of the machine model of the Selectable models machine monitor can be changed with the WA100 machine model select function.
Page 532: Pm Clinic Inspection Chart
130 Testing and adjusting, Part 3 SEN03838-00 Pm clinic inspection chart Pm clinic inspection chart WA250-6 Serial No. 75001 and up Machine serial No. Hours inspection Engine serial No. SAA6D107E-1 # Work order No. Date of execution Service Meter Serviceman...
Page 533 130 Testing and adjusting, Part 3 SEN03838-00 Pm clinic inspection chart WA250-6 Serial No. 75001 and up <>: Reference value Standard Service limit Measurement Item Conditions Unit value for new Pass Fail value results machine Engine low idle 3.3 – 4.1 Max.
Page 534 130 Testing and adjusting, Part 3 SEN03838-00 Pm clinic inspection chart WA250, 250PZ-6 30-130...
Page 535 SEN03838-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03838-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 30-130...
Page 536: 40 Troubleshooting
SEN03839-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 100 Failure code table and fuse locations Failure codes table............................2 Fuse locations..............................8 WA250, 250PZ-6 40-100...
Page 537: Failure Codes Table
100 Failure code table and fuse locations SEN03839-00 Failure codes table Failure codes table Failure Action Category of Reference Troubled part Trouble Controller code code record document No. Mechanical 2G40ZG Brake Oil pressure reduction system Mechanical 6091NX HST filter Clogging system Mechanical 989FN1...
Page 538 100 Failure code table and fuse locations SEN03839-00 Failure codes table Failure Action Category of Reference Troubled part Trouble Controller code code record document No. Mechanical CA234 Engine Overspeed system Ne speed sensor power Electrical CA238 Abnormality supply system Electrical CA271 IMV (IMA) Short circuit...
Page 539 100 Failure code table and fuse locations SEN03839-00 Failure codes table Failure Action Category of Reference Troubled part Trouble Controller code code record document No. Abnormally high pressure Electrical CA553 Common rail pressure system Electrical CA559 Supply pump Low rail pressure 1 system Electrical CA689...
Page 540 100 Failure code table and fuse locations SEN03839-00 Failure codes table Failure Action Category of Reference Troubled part Trouble Controller code code record document No. Controller solenoid power Electrical DAJ2KK Low voltage supply system HST controller load power Electrical DAJ2L3 Hot short supply holding line system...
Page 541 100 Failure code table and fuse locations SEN03839-00 Failure codes table Failure Action Category of Reference Troubled part Trouble Controller code code record document No. Travel speed range selec- Disconnection/Ground Electrical DF10KA tor switch fault system Travel speed range selec- Electrical DF10KB Hot short...
Page 542 100 Failure code table and fuse locations SEN03839-00 Failure codes table Failure Action Category of Reference Troubled part Trouble Controller code code record document No. Electrical DX20KB Clutch solenoid Ground fault system Electrical DX20KY Clutch solenoid Hot short system Electrical DXH7KB Reverse solenoid Ground fault system...
Page 543: Fuse Locations
100 Failure code table and fuse locations SEN03839-00 Fuse locations Fuse locations Connection table of fuse box and slow blow fuse This connection table indicates the devices to which the power of the fuse box and slow blow fuse is supplied.
Page 544 100 Failure code table and fuse locations SEN03839-00 Fuse locations Fuse box: FS2 Type of power supply (Power source) Fuse No. Fuse capacity Destination of power (*) 20 A Air conditioner blower Air conditioner compressor Beacon 20 A Working lamp (Front: For addition) Rotary lamp 20 A Glass heater...
Page 545 100 Failure code table and fuse locations SEN03839-00 Fuse locations Slow blow fuse Type of power supply (Power source) Fuse capacity Destination of power Fuse box FS1 No.8 – 15 80 A Fuse box FS2 No.1 – 15 Accessory power supply (Battery) 120A Engine intake air heater relay Unswitched power supply (Battery)
Page 546 100 Failure code table and fuse locations SEN03839-00 Fuse locations WA250, 250PZ-6 40-100...
Page 547 SEN03839-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03839-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-100...
Page 548 SEN03840-01 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 200 General information on troubleshooting Points to remember when troubleshooting ..................... 2 Sequence of events in troubleshooting......................3 Testing before troubleshooting........................4 Classification and procedures of troubleshooting ...................
Page 549: Points To Remember When Troubleshooting
200 General information on troubleshooting SEN03840-01 Points to remember when troubleshooting General information on troubleshooting Points to remember when troubleshooting Stop the machine in a level place, and check that the safety pin, blocks, and parking brake are securely fitted. When carrying out the operation with 2 or more workers, keep strictly to the agreed signals, and do not allow any unauthorized person to come near.
Page 550: Sequence Of Events In Troubleshooting
200 General information on troubleshooting SEN03840-01 Sequence of events in troubleshooting Sequence of events in troubleshooting WA250, 250PZ-6 40-200...
Page 551: Testing Before Troubleshooting
200 General information on troubleshooting SEN03840-01 Testing before troubleshooting Testing before troubleshooting Item Criteria Remedy Check of level and type of fuel — Add fuel Check for foreign matter in fuel — Clean or drain Check fuel filter and fuel pre-filter for clogging Check of fuel filter for clogging —...
Page 552: Classification And Procedures Of Troubleshooting
200 General information on troubleshooting SEN03840-01 Classification and procedures of troubleshooting Classification and procedures of troubleshooting Classification of troubleshooting Mode Contents Display of Troubleshooting by failure code (Display of code) code E-mode Troubleshooting of electrical system H-mode Troubleshooting of hydraulic and mechanical system S-mode Troubleshooting of engine Procedure for troubleshooting...
Page 553 200 General information on troubleshooting SEN03840-01 Classification and procedures of troubleshooting Phenomena looking like troubles and troubleshooting Nos. Troubleshooting Phenomena looking like trouble Code E-mode H-mode S-mode display Phenomena related to action codes and failure codes 1 Action codes are displayed on machine monitor Check failure code 2 If failure code display function is checked, failure codes are displayed Phenomena related to engine...
Page 554 200 General information on troubleshooting SEN03840-01 Classification and procedures of troubleshooting Phenomena related to work equipment 34 The lift arm does not rise or lower H-12 35 The lift arm moves slowly or the lift arm rising force is insufficient H-13 36 When rising, the lift arm comes to move slowly at specific height H-14...
Page 555: Information Contained In Troubleshooting Table
200 General information on troubleshooting SEN03840-01 Information contained in troubleshooting table Information contained in troubleshooting table Action code Failure code Trouble Problem that appears on machine Monitor Monitor display display Contents of State where the monitor panel or controller detects the trouble trouble Action of Action taken by machine monitor or controller to protect system or devices when engine con-...
Page 556 200 General information on troubleshooting SEN03840-01 Information contained in troubleshooting table Related circuit diagram This is the excerpted circuit diagram related to trouble • Connector No.: Indicates (Model – No. of pins) (Color) • “Connector No. and pin No.” from each branching/ merging point: Shows the ends of branch or source of merging within the parts of the same wiring harness.
Page 557: Connection Table For Connector Pin Numbers
200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers Connection table for connector pin numbers (Rev. 2009.04) a The terms of male and female refer to the pins, while the terms of male housing and female housing refer to the mating portion of the housing.
Page 558 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 559 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 560 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 561 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 562 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 563 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 564 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 565 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 566 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 567 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 568 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 569 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 570 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 571 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 572 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 573 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 574 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 575 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 576 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 577 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 578 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 579 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 580 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 581 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 582 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 583 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 584 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 585 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 586 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 587 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 588 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 589 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 590 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 591 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers 40-200 WA250, 250PZ-6...
Page 592 200 General information on troubleshooting SEN03840-01 Connection table for connector pin numbers WA250, 250PZ-6 40-200...
Page 593: T- Branch Box And T- Branch Adapter Table
200 General information on troubleshooting SEN03840-01 T- branch box and T- branch adapter table T- branch box and T- branch adapter table (Rev. 2009.03) a The vertical column indicates a part number of T-branch box or T-branch adapter while the horizontal column indicates a part number of harness checker assembly.
Page 594 200 General information on troubleshooting SEN03840-01 T- branch box and T- branch adapter table T-adapter kit Identification Part No. Part name symbol 799-601-7120 Adapter for M q q q 799-601-7130 Adapter for M q q q 799-601-7340 Adapter for M 799-601-7140 Adapter for S q q q 799-601-7150 Adapter for S (White)
Page 595 200 General information on troubleshooting SEN03840-01 T- branch box and T- branch adapter table T-adapter kit Identification Part No. Part name symbol 799-601-9330 Case 799-601-9340 Case 799-601-9350 Adapter for DRC DRC-40 799-601-9360 Adapter for DRC DRC-24 799-601-9410* Socket for engine (CRI-T2) Adapter for engine (CRI-T2) 799-601-9420 Adapter for engine (CRI-T3) PFUEL...
Page 596 200 General information on troubleshooting SEN03840-01 T- branch box and T- branch adapter table WA250, 250PZ-6 40-200...
Page 597 SEN03840-01 WA250-6, WA250PZ-6 Wheel loader Form No. SEN03840-01 ©2009 KOMATSU All Rights Reserved Printed in Japan 06-09 40-200...
Page 598: Troubleshooting By Failure Code (Display Of Code), Part
SEN03841-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 310 Troubleshooting by failure code (Display of code), Part 1 Failure code [2G40GZ] Brake: Oil pressure reduction ..................2 Failure code [6091NX] HST filter: Clogging ....................4 Failure code [989FN1] Travel speed: Overrun alarm..................
Page 599: Failure Code [2G40Gz] Brake: Oil Pressure Reduction
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [2G40GZ] Brake: Oil pressure reduction Failure code [2G40GZ] Brake: Oil pressure reduction Action code Failure code Brake: Oil pressure reduction Trouble (Machine monitor system) 2G40GZ Contents of •...
Page 600 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [2G40GZ] Brake: Oil pressure reduction Related circuit diagram WA250, 250PZ-6 40-310...
Page 601: Failure Code [6091Nx] Hst Filter: Clogging
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [6091NX] HST filter: Clogging Failure code [6091NX] HST filter: Clogging Action code Failure code HST filter: Clogging Trouble (Machine monitor system) 6091NX Contents of • When HST oil temperature was above 50°C, HST oil filter clogging sensor signal circuit was closed trouble (in contact with GND).
Page 602 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [6091NX] HST filter: Clogging WA250, 250PZ-6 40-310...
Page 603: Failure Code [989Fn1] Travel Speed: Overrun Alarm
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [989FN1] Travel speed: Overrun alarm Failure code [989FN1] Travel speed: Overrun alarm Action code Failure code Travel speed: Overrun alarm Trouble (Machine monitor system) 989FN1 Contents of •...
Page 604 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [989FN1] Travel speed: Overrun alarm WA250, 250PZ-6 40-310...
Page 605: Failure Code [Ab00L6] Alternator R System: Hot Short
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [AB00L6] Alternator R system: Hot short Failure code [AB00L6] Alternator R system: Hot short Action code Failure code Alternator R system: Hot short Trouble (Machine monitor system) AB00L6 Contents of •...
Page 606 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [AB00L6] Alternator R system: Hot short Related circuit diagram WA250, 250PZ-6 40-310...
Page 607: Failure Code [Ab00Ma] Alternator R System: Ground Fault/Disconnection Charge/Low Charge Voltage
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [AB00MA] Alternator R system: Ground fault/Disconnection charge/Low charge voltage Failure code [AB00MA] Alternator R system: Ground fault/Disconnection charge/Low charge voltage Action code Failure code Alternator R system: Ground fault/Disconnection charge/Low Trouble charge voltage AB00MA...
Page 608 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [AB00MA] Alternator R system: Ground fault/Disconnection charge/Low charge voltage Related circuit diagram WA250, 250PZ-6 40-310...
Page 609: Failure Code [B@Bazg] Engine: Oil Pressure Reduction
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [B@BAZG] Engine: Oil pressure reduction Failure code [B@BAZG] Engine: Oil pressure reduction Action code Failure code Engine: Oil pressure reduction Trouble (Engine controller system) B@BAZG Contents of •...
Page 610: Failure Code [B@Bcns] Engine: Overheat
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [B@BCNS] Engine: Overheat Failure code [B@BCNS] Engine: Overheat Action code Failure code Engine: Overheat Trouble (Engine controller system) B@BCNS Contents of • While engine was running, engine coolant temperature sensor signal circuit detected engine coolant trouble overheat.
Page 611: Failure Code [B@Bczk] Engine: Low Coolant Level
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [B@BCZK] Engine: Low coolant level Failure code [B@BCZK] Engine: Low coolant level Action code Failure code Engine: Low coolant level Trouble (Machine monitor system) B@BCZK Contents of •...
Page 612 310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [B@BCZK] Engine: Low coolant level Related circuit diagram WA250, 250PZ-6 40-310...
Page 613: Failure Code [B@C6Ns] Front Brake: High Oil Temperature
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [B@C6NS] Front brake: High oil temperature Failure code [B@C6NS] Front brake: High oil temperature Action code Failure code Front brake: High oil temperature Trouble (Machine monitor system) B@C6NS •...
Page 614: Failure Code [B@Crns] Hst: High Oil Temperature
310 Troubleshooting by failure code (Display of code), Part 1 SEN03841-00 Failure code [B@CRNS] HST: High oil temperature Failure code [B@CRNS] HST: High oil temperature Action code Failure code HST: High oil temperature Trouble (Machine monitor system) B@CRNS Contents of •...
Page 615 SEN03841-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03841-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-310...
Page 616: Troubleshooting By Failure Code (Display Of Code), Part
SEN03842-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 320 Troubleshooting by failure code (Display of code), Part 2 Failure code [CA111] Abnormality in engine controller ................... 3 Failure code [CA115] Engine Ne or Bkup speed sensor error ................ 4 Failure code [CA122] Charge pressure sensor high error ................
Page 617 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA324] Injector #3 open/short error ..................40 Failure code [CA325] Injector #6 open/short error ..................42 Failure code [CA331] Injector #2 open/short error ..................44 Failure code [CA332] Injector #4 open/short error ..................46 Failure code [CA342] Calibration code inconsistency...................
Page 618: Failure Code [Ca111] Abnormality In Engine Controller
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA111] Abnormality in engine controller Failure code [CA111] Abnormality in engine controller Action code Failure code Abnormality in engine controller Trouble (Engine controller system) CA111 Contents of •...
Page 619: Failure Code [Ca115] Engine Ne Or Bkup Speed Sensor Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA115] Engine Ne or Bkup speed sensor error Failure code [CA115] Engine Ne or Bkup speed sensor error Action code Failure code Engine Ne or Bkup speed sensor error Trouble (Engine controller system) CA115...
Page 620 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA115] Engine Ne or Bkup speed sensor error WA250, 250PZ-6 40-320...
Page 621: Failure Code [Ca122] Charge Pressure Sensor High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA122] Charge pressure sensor high error Failure code [CA122] Charge pressure sensor high error Action code Failure code Charge pressure sensor high error Trouble (Engine controller system) CA122 Contents of •...
Page 622 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA122] Charge pressure sensor high error Related circuit diagram WA250, 250PZ-6 40-320...
Page 623: Failure Code [Ca123] Charge Pressure Sensor Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA123] Charge pressure sensor low error Failure code [CA123] Charge pressure sensor low error Action code Failure code Charge pressure sensor low error Trouble (Engine controller system) CA123 Contents of •...
Page 624 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA123] Charge pressure sensor low error Related circuit diagram WA250, 250PZ-6 40-320...
Page 625: Failure Code [Ca131] Throttle Sensor High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA131] Throttle sensor high error Failure code [CA131] Throttle sensor high error Action code Failure code Throttle sensor high error Trouble (Engine controller system) CA131 Contents of •...
Page 626 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA131] Throttle sensor high error Related circuit diagram WA250, 250PZ-6 40-320...
Page 627: Failure Code [Ca132] Throttle Sensor Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA132] Throttle sensor low error Failure code [CA132] Throttle sensor low error Action code Failure code Throttle sensor low error Trouble (Engine controller system) CA132 Contents of •...
Page 628 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA132] Throttle sensor low error Related circuit diagram WA250, 250PZ-6 40-320...
Page 629: Failure Code [Ca144] Coolant Sensor High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA144] Coolant sensor high error Failure code [CA144] Coolant sensor high error Action code Failure code Coolant sensor high error Trouble (Engine controller system) CA144 Contents of •...
Page 630 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA144] Coolant sensor high error Related circuit diagram WA250, 250PZ-6 40-320...
Page 631: Failure Code [Ca145] Coolant Sensor Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA145] Coolant sensor low error Failure code [CA145] Coolant sensor low error Action code Failure code Coolant sensor low error Trouble (Engine controller system) CA145 Contents of •...
Page 632 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA145] Coolant sensor low error Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. EC1 (male) Coolant temperature Resistance...
Page 633: Failure Code [Ca153] Charge Temperature Sensor High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA153] Charge temperature sensor high error Failure code [CA153] Charge temperature sensor high error Action code Failure code Charge temperature sensor high error Trouble (Engine controller system) CA153 Contents of •...
Page 634 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA153] Charge temperature sensor high error Related circuit diagram WA250, 250PZ-6 40-320...
Page 635: Failure Code [Ca154] Charge Temperature Sensor Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA154] Charge temperature sensor low error Failure code [CA154] Charge temperature sensor low error Action code Failure code Charge temperature sensor low error Trouble (Engine controller system) CA154 Contents of •...
Page 636 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA154] Charge temperature sensor low error Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. EC1 (female) Charge temperature Resistance...
Page 637: Failure Code [Ca155] Derating Of Speed By Abnormally High Charge Temperature
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA155] Derating of speed by abnormally high charge temperature Failure code [CA155] Derating of speed by abnormally high charge temperature Action code Failure code Derating of speed by abnormally high charge temperature Trouble (Engine controller system) CA155...
Page 638 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA155] Derating of speed by abnormally high charge temperature WA250, 250PZ-6 40-320...
Page 639: Failure Code [Ca187] Sensor Power Supply 2 Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA187] Sensor power supply 2 low error Failure code [CA187] Sensor power supply 2 low error Action code Failure code Sensor power supply 2 low error Trouble (Engine controller system) CA187 Contents of...
Page 640 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA187] Sensor power supply 2 low error Related circuit diagram WA250, 250PZ-6 40-320...
Page 641: Failure Code [Ca221] Atmospheric Pressure Sensor High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA221] Atmospheric pressure sensor high error Failure code [CA221] Atmospheric pressure sensor high error Action code Failure code Ambient pressure sensor high error Trouble (Engine controller system) CA221 Contents of •...
Page 642 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA221] Atmospheric pressure sensor high error Related circuit diagram WA250, 250PZ-6 40-320...
Page 643: Failure Code [Ca222] Atmospheric Sensor Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA222] Atmospheric sensor low error Failure code [CA222] Atmospheric sensor low error Action code Failure code Atmospheric sensor low error Trouble (Engine controller system) CA222 Contents of •...
Page 644 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA222] Atmospheric sensor low error Related circuit diagram WA250, 250PZ-6 40-320...
Page 645: Failure Code [Ca227] Sensor Power Supply 2 High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA227] Sensor power supply 2 high error Failure code [CA227] Sensor power supply 2 high error Action code Failure code Sensor power supply 2 high error Trouble (Engine controller system) CA227 Contents of...
Page 646: Failure Code [Ca234] Engine Overspeed
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA234] Engine overspeed Failure code [CA234] Engine overspeed Action code Failure code Engine Overspeed Trouble (Engine controller system) CA234 Contents of • Engine speed is above upper control limit. trouble Action of •...
Page 647: Failure Code [Ca238] Ne Speed Sensor Power Supply Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA238] Ne speed sensor power supply error Failure code [CA238] Ne speed sensor power supply error Action code Failure code Ne speed sensor supply power error Trouble (Engine controller system) CA238 Contents of...
Page 648: Failure Code [Ca271] Imv (Ima) Short Circuit
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA271] IMV (IMA) Short circuit Failure code [CA271] IMV (IMA) Short circuit Action code Failure code IMV (IMA) Short circuit Trouble (Engine controller system) CA271 Contents of •...
Page 649: Failure Code [Ca272] Imv (Ima) Disconnection
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA272] IMV (IMA) Disconnection Failure code [CA272] IMV (IMA) Disconnection Action code Failure code IMV (IMA) Disconnection Trouble (Engine controller system) CA272 Contents of • There is disconnection in supply pump actuator drive circuit. trouble Action of •...
Page 650 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA272] IMV (IMA) Disconnection Related circuit diagram WA250, 250PZ-6 40-320...
Page 651: Failure Code [Ca322] Injector #1 Open/Short Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA322] Injector #1 open/short error Failure code [CA322] Injector #1 open/short error Action code Failure code Injector #1 open/short error Trouble (Engine controller system) CA322 Contents of •...
Page 652 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA322] Injector #1 open/short error Related circuit diagram WA250, 250PZ-6 40-320...
Page 653: Failure Code [Ca323] Injector #5 Open/Short Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA323] Injector #5 open/short error Failure code [CA323] Injector #5 open/short error Action code Failure code Injector #5 open/short error Trouble (Engine controller system) CA323 Contents of •...
Page 654 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA323] Injector #5 open/short error Related circuit diagram WA250, 250PZ-6 40-320...
Page 655: Failure Code [Ca324] Injector #3 Open/Short Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA324] Injector #3 open/short error Failure code [CA324] Injector #3 open/short error Action code Failure code Injector #3 open/short error Trouble (Engine controller system) CA324 Contents of •...
Page 656 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA324] Injector #3 open/short error Related circuit diagram WA250, 250PZ-6 40-320...
Page 657: Failure Code [Ca325] Injector #6 Open/Short Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA325] Injector #6 open/short error Failure code [CA325] Injector #6 open/short error Action code Failure code Injector #6 open/short error Trouble (Engine controller system) CA325 Contents of •...
Page 658 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA325] Injector #6 open/short error Related circuit diagram WA250, 250PZ-6 40-320...
Page 659: Failure Code [Ca331] Injector #2 Open/Short Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA331] Injector #2 open/short error Failure code [CA331] Injector #2 open/short error Action code Failure code Injector #2 open/short error Trouble (Engine controller system) CA331 Contents of •...
Page 660 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA331] Injector #2 open/short error Related circuit diagram WA250, 250PZ-6 40-320...
Page 661: Failure Code [Ca332] Injector #4 Open/Short Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA332] Injector #4 open/short error Failure code [CA332] Injector #4 open/short error Action code Failure code Injector #4 open/short error Trouble (Engine controller system) CA332 Contents of •...
Page 662 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA332] Injector #4 open/short error Related circuit diagram WA250, 250PZ-6 40-320...
Page 663: Failure Code [Ca342] Calibration Code Inconsistency
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA342] Calibration code inconsistency Failure code [CA342] Calibration code inconsistency Action code Failure code Calibration code inconsistency Trouble (Engine controller system) CA342 Contents of • Matching error occurred in engine controller data. trouble Action of •...
Page 664 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA342] Calibration code inconsistency WA250, 250PZ-6 40-320...
Page 665: Failure Code [Ca351] Injectors Drive Circuit Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA351] Injectors drive circuit error Failure code [CA351] Injectors drive circuit error Action code Failure code Injectors drive circuit error Trouble (Engine controller system) CA351 Contents of •...
Page 666 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA351] Injectors drive circuit error Related circuit diagram WA250, 250PZ-6 40-320...
Page 667: Failure Code [Ca352] Sensor Power Supply 1 Low Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA352] Sensor power supply 1 low error Failure code [CA352] Sensor power supply 1 low error Action code Failure code Sensor power supply 1 low error Trouble (Engine controller system) CA352 Contents of...
Page 668 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA352] Sensor power supply 1 low error Related circuit diagram WA250, 250PZ-6 40-320...
Page 669: Failure Code [Ca386] Sensor Power Supply 1 High Error
320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA386] Sensor power supply 1 high error Failure code [CA386] Sensor power supply 1 high error Action code Failure code Sensor power supply 1 high error Trouble (Engine controller system) CA386 Contents of...
Page 670 320 Troubleshooting by failure code (Display of code), Part 2 SEN03842-00 Failure code [CA386] Sensor power supply 1 high error WA250, 250PZ-6 40-320...
Page 671 SEN03842-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03842-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-320...
Page 672: Troubleshooting By Failure Code (Display Of Code), Part
SEN03843-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 330 Troubleshooting by failure code (Display of code), Part 3 Failure code [CA428] Abnormally high level in water sensor................4 Failure code [CA429] Abnormally low level in water sensor ................6 Failure code [CA431] Idle validation switch error....................
Page 673 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2311] Abnormality in IMV (IMA) solenoid ................50 Failure code [CA2555] Intake heater relay disconnection error ..............52 Failure code [CA2556] Intake heater relay short circuit error................ 54 40-330 WA250, 250PZ-6...
Page 674 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 WA250, 250PZ-6 40-330...
Page 675: Failure Code [Ca428] Abnormally High Level In Water Sensor
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA428] Abnormally high level in water sensor Failure code [CA428] Abnormally high level in water sensor Action code Failure code Abnormally high level in water sensor Trouble (Engine controller system) CA428 Contents of...
Page 676 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA428] Abnormally high level in water sensor Related circuit diagram WA250, 250PZ-6 40-330...
Page 677: Failure Code [Ca429] Abnormally Low Level In Water Sensor
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA429] Abnormally low level in water sensor Failure code [CA429] Abnormally low level in water sensor Action code Failure code Abnormally low level in water sensor Trouble (Engine controller system) CA429 Contents of...
Page 678 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA429] Abnormally low level in water sensor Related circuit diagram WA250, 250PZ-6 40-330...
Page 679: Failure Code [Ca431] Idle Validation Switch Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA431] Idle validation switch error Failure code [CA431] Idle validation switch error Action code Failure code Idle validation switch error Trouble (Engine controller system) CA431 Contents of •...
Page 680 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA431] Idle validation switch error Causes Standard value in normal state/Remarks on troubleshooting Possible causes Connecting parts among accelerator pedal, engine unit wiring har- and standard ness, and engine controller are suspected. Inspect them directly. Defective wiring harness value in normal •...
Page 681 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA431] Idle validation switch error Fig. 1 Throttle: Throttle sensor signal voltage Idle validation: Idle validation switch signal voltage A: Voltage when pedal opened + 0.03 x (Voltage when pedal pressed Voltage –...
Page 682 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA431] Idle validation switch error WA250, 250PZ-6 40-330...
Page 683: Failure Code [Ca432] Idle Validation Action Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA432] Idle validation action error Failure code [CA432] Idle validation action error Action code Failure code Idle validation action error Trouble (Engine controller system) CA432 Contents of •...
Page 684 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA432] Idle validation action error Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness among all pins between EC2 Resis- Min.
Page 685 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA432] Idle validation action error Related circuit diagram 40-330 WA250, 250PZ-6...
Page 686 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA432] Idle validation action error Fig. 1 Throttle: Throttle sensor signal voltage Idle validation: Idle validation switch signal voltage A: Voltage when pedal opened + 0.03 x (Voltage when pedal pressed Voltage –...
Page 687: Failure Code [Ca435] Engine Oil Pressure Switch Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA435] Engine oil pressure switch error Failure code [CA435] Engine oil pressure switch error Action code Failure code Engine oil pressure switch error Trouble (Engine controller system) CA435 Contents of •...
Page 688: Failure Code [Ca441] Battery Voltage Low Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA441] Battery voltage low error Failure code [CA441] Battery voltage low error Action code Failure code Battery voltage low error Trouble (Engine controller system) CA441 Contents of •...
Page 689 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA441] Battery voltage low error Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Ground fault in wiring har- Wiring harness between fuse No.
Page 690 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA441] Battery voltage low error Related circuit diagram WA250, 250PZ-6 40-330...
Page 691: Failure Code [Ca442] Battery Voltage High Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA442] Battery voltage high error Failure code [CA442] Battery voltage high error Action code Failure code Battery voltage high error Trouble (Engine controller system) CA442 Contents of •...
Page 692 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA442] Battery voltage high error Related circuit diagram WA250, 250PZ-6 40-330...
Page 693: Failure Code [Ca449] Common Rail Pressure High Error 2
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA449] Common rail pressure high error 2 Failure code [CA449] Common rail pressure high error 2 Action code Failure code Common rail pressure high error 2 Trouble (Engine controller system) CA449 Contents of...
Page 694 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA449] Common rail pressure high error 2 WA250, 250PZ-6 40-330...
Page 695: Failure Code [Ca451] Common Rail Pressure Sensor High Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA451] Common rail pressure sensor high error Failure code [CA451] Common rail pressure sensor high error Action code Failure code Common rail pressure sensor high error Trouble (Engine controller system) CA451 Contents of...
Page 696 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA451] Common rail pressure sensor high error Related circuit diagram WA250, 250PZ-6 40-330...
Page 697: Failure Code [Ca452] Common Rail Pressure Sensor Low Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA452] Common rail pressure sensor low error Failure code [CA452] Common rail pressure sensor low error Action code Failure code Common rail pressure sensor low error Trouble (Engine controller system) CA452 Contents of...
Page 698 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA452] Common rail pressure sensor low error Related circuit diagram WA250, 250PZ-6 40-330...
Page 699: Failure Code [Ca488] Derating Of Torque By Abnormally High Charge Temperature
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA488] Derating of torque by abnormally high charge temperature Failure code [CA488] Derating of torque by abnormally high charge temperature Action code Failure code Derating of torque by abnormally high charge temperature Trouble (Engine controller system) CA488...
Page 700: Failure Code [Ca553] Common Rail Pressure High Error 1
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA553] Common rail pressure high error 1 Failure code [CA553] Common rail pressure high error 1 Action code Failure code Common rail pressure high error 1 Trouble (Engine controller system) CA553 Contents of...
Page 701: Failure Code [Ca559] Supply Pump Pressure Very Low Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA559] Supply pump pressure very low error Failure code [CA559] Supply pump pressure very low error Action code Failure code Supply pump pressure very low error Trouble (Engine controller system) CA559 Contents of...
Page 702 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA559] Supply pump pressure very low error WA250, 250PZ-6 40-330...
Page 703: Failure Code [Ca689] Engine Ne Speed Sensor Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA689] Engine Ne speed sensor error Failure code [CA689] Engine Ne speed sensor error Action code Failure code Engine Ne speed sensor error Trouble (Engine controller system) CA689 Contents of •...
Page 704 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA689] Engine Ne speed sensor error Causes Standard value in normal state/Remarks on troubleshooting Connecting parts among engine Ne speed sensor, engine wiring harness, and engine controller are suspected. Inspect them directly. Defective wiring harness •...
Page 705: Failure Code [Ca731] Engine Bkup Speed Sensor Phase Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA731] Engine Bkup speed sensor phase error Failure code [CA731] Engine Bkup speed sensor phase error Action code Failure code Engine Bkup speed sensor phase error Trouble (Engine controller system) CA731 Contents of...
Page 706: Failure Code [Ca757] All Continuous Data Lost Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA757] All continuous data lost error Failure code [CA757] All continuous data lost error Action code Failure code All continuous data lost error Trouble (Engine controller system) CA757 Contents of •...
Page 707 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA757] All continuous data lost error Causes Standard value in normal state/Remarks on troubleshooting Connecting parts among fuse No. 4 of fuse box FS1, engine unit wiring harness, and engine controller are suspected. Inspect them directly.
Page 708 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA757] All continuous data lost error Related circuit diagram WA250, 250PZ-6 40-330...
Page 709: Failure Code [Ca778] Engine Bkup Speed Sensor Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA778] Engine Bkup speed sensor error Failure code [CA778] Engine Bkup speed sensor error Action code Failure code Engine Bkup speed sensor error Trouble (Engine controller system) CA778 Contents of •...
Page 710 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA778] Engine Bkup speed sensor error Causes Standard value in normal state/Remarks on troubleshooting Connecting parts among engine Bkup speed sensor, engine wiring harness, and engine controller are suspected. Inspect them directly. Defective wiring harness •...
Page 711: Failure Code [Ca1633] Komnet Datalink Timeout Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA1633] KOMNET datalink timeout error Failure code [CA1633] KOMNET datalink timeout error Action code Failure code KOMNET datalink timeout error Trouble (Engine controller system) CA1633 Contents of •...
Page 712 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA1633] KOMNET datalink timeout error Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between EC2 (female) (46), Resis- Min.
Page 713 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA1633] KOMNET datalink timeout error Related circuit diagram 40-330 WA250, 250PZ-6...
Page 714 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA1633] KOMNET datalink timeout error WA250, 250PZ-6 40-330...
Page 715: Failure Code [Ca2185] Throttle Sensor Supply Voltage High Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2185] Throttle sensor supply voltage high error Failure code [CA2185] Throttle sensor supply voltage high error Action code Failure code Throttle sensor supply voltage high error Trouble (Engine controller system) CA2185 Contents of...
Page 716 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2185] Throttle sensor supply voltage high error Related circuit diagram WA250, 250PZ-6 40-330...
Page 717: Failure Code [Ca2186] Throttle Sensor Power Supply Low Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2186] Throttle sensor power supply low error Failure code [CA2186] Throttle sensor power supply low error Action code Failure code Throttle sensor power supply voltage low error Trouble (Engine controller system) CA2186...
Page 718 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2186] Throttle sensor power supply low error Related circuit diagram WA250, 250PZ-6 40-330...
Page 719: Failure Code [Ca2249] Supply Pump Pressure Very Low Error 2
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2249] Supply pump pressure very low error 2 Failure code [CA2249] Supply pump pressure very low error 2 Action code Failure code Supply pump pressure very low error 2 Trouble (Engine controller system) CA2249...
Page 720 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2249] Supply pump pressure very low error 2 WA250, 250PZ-6 40-330...
Page 721: Failure Code [Ca2311] Abnormality In Imv (Ima) Solenoid
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2311] Abnormality in IMV (IMA) solenoid Failure code [CA2311] Abnormality in IMV (IMA) solenoid Action code Failure code Abnormality in IMV (IMA) solenoid Trouble (Engine controller system) CA2311 Contents of •...
Page 722 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2311] Abnormality in IMV (IMA) solenoid Related circuit diagram WA250, 250PZ-6 40-330...
Page 723: Failure Code [Ca2555] Intake Heater Relay Disconnection Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2555] Intake heater relay disconnection error Failure code [CA2555] Intake heater relay disconnection error Action code Failure code Intake heater relay disconnection error Trouble (Engine controller system) CA2555 Contents of •...
Page 724 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2555] Intake heater relay disconnection error Related circuit diagram WA250, 250PZ-6 40-330...
Page 725: Failure Code [Ca2556] Intake Heater Relay Short Circuit Error
330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2556] Intake heater relay short circuit error Failure code [CA2556] Intake heater relay short circuit error Action code Failure code Intake heater relay short circuit error Trouble (Engine controller system) CA2556 Contents of...
Page 726 330 Troubleshooting by failure code (Display of code), Part 3 SEN03843-00 Failure code [CA2556] Intake heater relay short circuit error Related circuit diagram WA250, 250PZ-6 40-330...
Page 727 SEN03843-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03843-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-330...
Page 728: Troubleshooting By Failure Code (Display Of Code), Part
SEN03844-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 340 Troubleshooting by failure code (Display of code), Part 4 Failure code [D160KY] Backup alarm/lamp relay 1 circuit: Hot short ............. 2 Failure code [D192KY] ECSS solenoid relay: Hot short .................
Page 729: Failure Code [D160Ky] Backup Alarm/Lamp Relay 1 Circuit: Hot Short
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D160KY] Backup alarm/lamp relay 1 circuit: Hot short Failure code [D160KY] Backup alarm/lamp relay 1 circuit: Hot short Action code Failure code Backup alarm/lamp relay 1 circuit: Hot short Trouble (Machine monitor system) D160KY...
Page 730 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D160KY] Backup alarm/lamp relay 1 circuit: Hot short Related circuit diagram WA250, 250PZ-6 40-340...
Page 731: Failure Code [D192Ky] Ecss Solenoid Relay: Hot Short
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D192KY] ECSS solenoid relay: Hot short Failure code [D192KY] ECSS solenoid relay: Hot short Action code Failure code ECSS solenoid relay: Hot short Trouble (Machine monitor system) D192KY Contents of •...
Page 732 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D192KY] ECSS solenoid relay: Hot short Related circuit diagram WA250, 250PZ-6 40-340...
Page 733: Failure Code [D1B0Ka] Hst Safety Relay: Disconnection
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D1B0KA] HST safety relay: Disconnection Failure code [D1B0KA] HST safety relay: Disconnection Action code Failure code HST safety relay: Disconnection Trouble (HST controller system) D1B0KA Contents of •...
Page 734 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D1B0KA] HST safety relay: Disconnection Related circuit diagram WA250, 250PZ-6 40-340...
Page 735: Failure Code [D1B0Kb] Hst Safety Relay: Ground Fault
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D1B0KB] HST safety relay: Ground fault Failure code [D1B0KB] HST safety relay: Ground fault Action code Failure code HST safety relay: Ground fault Trouble (HST controller system) D1B0KB Contents of •...
Page 736 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D1B0KB] HST safety relay: Ground fault Related circuit diagram WA250, 250PZ-6 40-340...
Page 737: Failure Code [D1B0Ky] Hst Safety Relay: Hot Short
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D1B0KY] HST safety relay: Hot short Failure code [D1B0KY] HST safety relay: Hot short Action code Failure code HST safety relay: Hot short Trouble (HST controller system) D1B0KY Contents of •...
Page 738 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D1B0KY] HST safety relay: Hot short Related circuit diagram WA250, 250PZ-6 40-340...
Page 739: Failure Code [D5Zhl6] Ign C System: Ground Fault/Disconnection
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D5ZHL6] IGN C system: Ground fault/Disconnection Failure code [D5ZHL6] IGN C system: Ground fault/Disconnection Action code Failure code IGN C system: Ground fault/Disconnection Trouble (Machine monitor system) D5ZHL6 •...
Page 740 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [D5ZHL6] IGN C system: Ground fault/Disconnection Related circuit diagram WA250, 250PZ-6 40-340...
Page 741: Failure Code [Daf3Kk] Unsw Power Supply: Ground Fault/Disconnection
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAF3KK] UNSW power supply: Ground fault/Disconnection Failure code [DAF3KK] UNSW power supply: Ground fault/ Disconnection Action code Failure code UNSW power supply: Ground fault/Disconnection Trouble (Machine monitor system) DAF3KK Contents of •...
Page 742 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAF3KK] UNSW power supply: Ground fault/Disconnection Related circuit diagram WA250, 250PZ-6 40-340...
Page 743: Failure Code [Dafrkr] Machine Monitor Can-Net Signal: Disconnection
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAFRKR] Machine monitor CAN-NET Signal: Disconnection Failure code [DAFRKR] Machine monitor CAN-NET Signal: Disconnection Action code Failure code Machine monitor CAN-NET Signal: Disconnection Trouble (HST controller system) DAFRKR Contents of •...
Page 744 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAFRKR] Machine monitor CAN-NET Signal: Disconnection Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between HST (female) (28), Resis- Min.
Page 745 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAFRKR] Machine monitor CAN-NET Signal: Disconnection Related circuit diagram 40-340 WA250, 250PZ-6...
Page 746 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAFRKR] Machine monitor CAN-NET Signal: Disconnection WA250, 250PZ-6 40-340...
Page 747: Failure Code [Daj0Kk] Hst Controller Power Supply: Low Voltage
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ0KK] HST controller power supply: Low voltage Failure code [DAJ0KK] HST controller power supply: Low voltage Action code Failure code HST controller power supply: Low voltage Trouble (HST controller system) DAJ0KK •...
Page 748 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ0KK] HST controller power supply: Low voltage Related circuit diagram WA250, 250PZ-6 40-340...
Page 749: Failure Code [Daj0Kt] Hst Controller Memory (Eeprom): Abnormality
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ0KT] HST controller memory (EEPROM): Abnormality Failure code [DAJ0KT] HST controller memory (EEPROM): Abnormality Action code Failure code HST controller memory (EEPROM): Abnormality Trouble (HST controller system) DAJ0KT Contents of •...
Page 750 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ0KT] HST controller memory (EEPROM): Abnormality WA250, 250PZ-6 40-340...
Page 751: Failure Code [Daj1L4] Hst Controller Main Power Line: Disconnection/Ground Fault
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ1L4] HST controller main power line: Disconnection/Ground fault Failure code [DAJ1L4] HST controller main power line: Disconnection/ Ground fault Action code Failure code HST controller main power line: Disconnection/Ground fault Trouble (HST controller system) DAJ1L4...
Page 752 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ1L4] HST controller main power line: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-340...
Page 753: Failure Code [Daj1L6] Hst Controller Main Power Line: Hot Short
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ1L6] HST controller main power line: Hot short Failure code [DAJ1L6] HST controller main power line: Hot short Action code Failure code HST controller main power line: Hot short Trouble (HST controller system) DAJ1L6...
Page 754 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ1L6] HST controller main power line: Hot short Related circuit diagram WA250, 250PZ-6 40-340...
Page 755: Failure Code [Daj2Kk] Controller Solenoid Power Supply: Low Voltage
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ2KK] Controller solenoid power supply: Low voltage Failure code [DAJ2KK] Controller solenoid power supply: Low voltage Action code Failure code Controller solenoid power supply: Low voltage Trouble (HST controller system) DAJ2KK •...
Page 756 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ2KK] Controller solenoid power supply: Low voltage Related circuit diagram WA250, 250PZ-6 40-340...
Page 757: Failure Code [Daj2L3] Hst Controller Load Power Supply Holding Line: Hot Short In Wiring Harness
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ2L3] HST controller load power supply holding line: Hot short in wiring harness Failure code [DAJ2L3] HST controller load power supply holding line: Hot short in wiring harness Action code Failure code HST controller load power supply holding line: Hot short in wiring...
Page 758 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ2L3] HST controller load power supply holding line: Hot short in wiring harness Related circuit diagram WA250, 250PZ-6 40-340...
Page 759: Failure Code [Daj2L4] Hst Controller Load Power Supply Holding Line: Disconnection/Ground Fault
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ2L4] HST controller load power supply holding line: Disconnection/Ground fault Failure code [DAJ2L4] HST controller load power supply holding line: Disconnection/Ground fault Action code Failure code HST controller load power supply holding line: Disconnection/ Trouble Ground fault DAJ2L4...
Page 760 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ2L4] HST controller load power supply holding line: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-340...
Page 761: Failure Code [Daj5Kx] Sensor 5V Power Supply: Out Of Output Range
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ5KX] Sensor 5V power supply: Out of output range Failure code [DAJ5KX] Sensor 5V power supply: Out of output range Action code Failure code Sensor 5V power supply: Out of output range Trouble (HST controller system) DAJ5KX...
Page 762 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ5KX] Sensor 5V power supply: Out of output range Related circuit diagram WA250, 250PZ-6 40-340...
Page 763: Failure Code [Daj9Kq] Hst Controller Model Selection: Disagreement Of Model Selection Signals
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJ9KQ] HST controller model selection: Disagreement of model selection signals Failure code [DAJ9KQ] HST controller model selection: Disagreement of model selection signals Action code Failure code HST controller model selection: Disagreement of model selection Trouble signals (Machine monitor system) DAJ9KQ...
Page 764: Failure Code [Dajrkr] Hst Controller Can-Net Signal: Disconnection
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection Action code Failure code HST controller CAN-NET signal: Disconnection Trouble (Machine monitor system) DAJRKR Contents of •...
Page 765 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between HST (female) (28), Resis- Min.
Page 766 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection Related circuit diagram WA250, 250PZ-6 40-340...
Page 767 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection When HST controller power supply circuit is defective Causes Standard value in normal state/Remarks on troubleshooting Broken fuse box FS1 fuse If fuse is broken, circuit probably has ground fault etc.
Page 768 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. L126 (male) Resistance Between (1) –...
Page 769 340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRKR] HST controller CAN-NET signal: Disconnection Related circuit diagram (When HST controller power supply circuit is defective) 40-340 WA250, 250PZ-6...
Page 770: Failure Code [Dajrma] Hst Controller: Disagreement In Option Selection
340 Troubleshooting by failure code (Display of code), Part 4 SEN03844-00 Failure code [DAJRMA] HST controller: Disagreement in option selection Failure code [DAJRMA] HST controller: Disagreement in option selection Action code Failure code HST controller: Disagreement in option selection Trouble (Machine monitor system) DAJRMA Contents of...
Page 771 SEN03844-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03844-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-340...
Page 772: Troubleshooting By Failure Code (Display Of Code), Part
SEN03845-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 350 Troubleshooting by failure code (Display of code), Part 5 Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line......... 3 Failure code [DD1NL4] Fan automatic reverse switch signal: Abnormality ............
Page 773 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 40-350 WA250, 250PZ-6...
Page 774: Failure Code [Db2Rkr] Engine Controller Can-Net: Disconnection In Signal Line
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line Action code Failure code Engine controller CAN-NET: Disconnection in signal line Trouble (HST controller system) DB2RKR...
Page 775 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between EC2 (female) (46), Resis- Min.
Page 776 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line Related circuit diagram WA250, 250PZ-6 40-350...
Page 777 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line When engine controller power supply circuit is defective Causes Standard value in normal state/Remarks on troubleshooting Defective fuse No. 4 in fuse If fuse box is damaged, circuit probably has ground fault etc.
Page 778 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DB2RKR] Engine controller CAN-NET: Disconnection in signal line Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting.
Page 779: Failure Code [Dd1Nl4] Fan Automatic Reverse Switch Signal: Abnormality
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DD1NL4] Fan automatic reverse switch signal: Abnormality Failure code [DD1NL4] Fan automatic reverse switch signal: Abnormality Action code Failure code Fan automatic reverse switch signal: Abnormality Trouble (HST controller system) DD1NL4 Contents of...
Page 780 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DD1NL4] Fan automatic reverse switch signal: Abnormality Related circuit diagram WA250, 250PZ-6 40-350...
Page 781: Failure Code [Dd1Nld] Fan Reverse Switch Signal: Abnormality
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DD1NLD] Fan reverse switch signal: Abnormality Failure code [DD1NLD] Fan reverse switch signal: Abnormality Action code Failure code Fan reverse switch signal: Abnormality Trouble (HST controller system) DD1NLD Contents of •...
Page 782 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DD1NLD] Fan reverse switch signal: Abnormality Related circuit diagram WA250, 250PZ-6 40-350...
Page 783: Failure Code [Ddb6Ka] Parking Brake Switch A: Disconnection/Hot Short
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6KA] Parking brake switch A: Disconnection/Hot short Failure code [DDB6KA] Parking brake switch A: Disconnection/Hot short Action code Failure code Parking brake switch A: Disconnection/Hot short Trouble (HST controller system) DDB6KA •...
Page 784 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6KA] Parking brake switch A: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-350...
Page 785: Failure Code [Ddb6Kb] Parking Brake Switch B: Ground Fault
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6KB] Parking brake switch B: Ground fault Failure code [DDB6KB] Parking brake switch B: Ground fault Action code Failure code Parking brake switch B: Ground fault Trouble (HST controller system) DDB6KB Contents of...
Page 786 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6KB] Parking brake switch B: Ground fault Related circuit diagram WA250, 250PZ-6 40-350...
Page 787: Failure Code [Ddb6Kz] Parking Brake Switch (Bottom Switch) Or Parking Brake Reminder Switch (Intermediate Switch): Trouble
350 Troubleshooting by failure code (Display of code), Part 5 Failure code [DDB6KZ] Parking brake switch (bottom switch) or parking brake reminder switch SEN03845-00 (intermediate switch): Trouble Failure code [DDB6KZ] Parking brake switch (bottom switch) or parking brake reminder switch (intermediate switch): Trouble Action code Failure code Parking brake switch (bottom switch) or parking brake reminder...
Page 788 350 Troubleshooting by failure code (Display of code), Part 5 Failure code [DDB6KZ] Parking brake switch (bottom switch) or parking brake reminder switch SEN03845-00 (intermediate switch): Trouble Related circuit diagram WA250, 250PZ-6 40-350...
Page 789: Failure Code [Ddb6L0] Parking Brake Switch A: Ground Fault
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6L0] Parking brake switch A: Ground fault Failure code [DDB6L0] Parking brake switch A: Ground fault Action code Failure code Parking brake switch A: Ground fault Trouble (HST controller system) DDB6L0 Contents of...
Page 790 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6L0] Parking brake switch A: Ground fault Related circuit diagram WA250, 250PZ-6 40-350...
Page 791: Failure Code [Ddb6L4] Parking Brake Switch B: Disconnection/Hot Short
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6L4] Parking brake switch B: Disconnection/Hot short Failure code [DDB6L4] Parking brake switch B: Disconnection/Hot short Action code Failure code Parking brake switch B: Disconnection/Hot short Trouble (HST controller system) DDB6L4 Contents of...
Page 792 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDB6L4] Parking brake switch B: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-350...
Page 793: Failure Code [Ddd7Kx] Travel Speed Control Dial Signal: Disconnection/Ground Fault
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDD7KX] Travel speed control dial signal: Disconnection/Ground fault Failure code [DDD7KX] Travel speed control dial signal: Disconnection/ Ground fault Action code Failure code Travel speed control dial signal: Disconnection/Ground fault Trouble (HST controller system) DDD7KX...
Page 794 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDD7KX] Travel speed control dial signal: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-350...
Page 795: Failure Code [Ddd7Ky] Travel Speed Control Dial Signal: Hot Short
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDD7KY] Travel speed control dial signal: Hot short Failure code [DDD7KY] Travel speed control dial signal: Hot short Action code Failure code Travel speed control dial signal: Hot short Trouble (HST controller system) DDD7KY...
Page 796 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDD7KY] Travel speed control dial signal: Hot short Related circuit diagram WA250, 250PZ-6 40-350...
Page 797: Failure Code [Dde5Ma] Emergency Steering Operation Switch: Disconnection
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDE5MA] Emergency steering operation switch: Disconnection Failure code [DDE5MA] Emergency steering operation switch: Disconnection Action code Failure code Emergency steering operation switch: Disconnection Trouble (Machine monitor system) DDE5MA Contents of •...
Page 798 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDE5MA] Emergency steering operation switch: Disconnection Related circuit diagram WA250, 250PZ-6 40-350...
Page 799: Failure Code [Ddk3Ka] Directional Selector Switch: Disconnection/Hot Short
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK3KA] Directional selector switch: Disconnection/Hot short Failure code [DDK3KA] Directional selector switch: Disconnection/Hot short Action code Failure code Directional selector switch: Disconnection/Hot short Trouble (HST controller system) DDK3KA Contents of •...
Page 800 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK3KA] Directional selector switch: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-350...
Page 801: Failure Code [Ddk3Kb] Directional Selector Switch: Ground Fault
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK3KB] Directional selector switch: Ground fault Failure code [DDK3KB] Directional selector switch: Ground fault Action code Failure code Directional selector switch: Ground fault Trouble (HST controller system) DDK3KB Contents of •...
Page 802 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK3KB] Directional selector switch: Ground fault Related circuit diagram WA250, 250PZ-6 40-350...
Page 803: Failure Code [Ddk6Ka] Fnr Lever: Disconnection/Ground Fault
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK6KA] FNR lever: Disconnection/Ground fault Failure code [DDK6KA] FNR lever: Disconnection/Ground fault Action code Failure code FNR lever: Disconnection/Ground fault Trouble (HST controller system) DDK6KA Contents of •...
Page 804 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK6KA] FNR lever: Disconnection/Ground fault Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then start engine and carry out troubleshooting. Condition becomes Relay (L106) is Replace neutral normal...
Page 805 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK6KA] FNR lever: Disconnection/Ground fault Related circuit diagram 40-350 WA250, 250PZ-6...
Page 806 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK6KA] FNR lever: Disconnection/Ground fault WA250, 250PZ-6 40-350...
Page 807: Failure Code [Ddk6Ky] Fnr Lever: Hot Short
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK6KY] FNR lever: Hot short Failure code [DDK6KY] FNR lever: Hot short Action code Failure code FNR lever: Hot short Trouble (HST controller system) DDK6KY Contents of •...
Page 808 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDK6KY] FNR lever: Hot short Related circuit diagram WA250, 250PZ-6 40-350...
Page 809: Failure Code [Dds5L6] Steering: Low Oil Pressure (Operation Of Emergency Steering)
350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDS5L6] Steering: Low oil pressure (Operation of emergency steering) Failure code [DDS5L6] Steering: Low oil pressure (Operation of emergency steering) Action code Failure code Steering: Low oil pressure (Operation of emergency steering) Trouble (Machine monitor system) DDS5L6...
Page 810 350 Troubleshooting by failure code (Display of code), Part 5 SEN03845-00 Failure code [DDS5L6] Steering: Low oil pressure (Operation of emergency steering) Related circuit diagram WA250, 250PZ-6 40-350...
Page 811 SEN03845-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03845-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-350...
Page 812: Troubleshooting By Failure Code (Display Of Code), Part
SEN03846-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 360 Troubleshooting by failure code (Display of code), Part 6 Failure code [DF10KA] Travel speed range selector switch: Disconnection/Ground fault......3 Failure code [DF10KB] Travel speed range selector switch: Hot short............
Page 813 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 40-360 WA250, 250PZ-6...
Page 814: Failure Code [Df10Ka] Travel Speed Range Selector Switch: Disconnection/Ground Fault
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DF10KA] Travel speed range selector switch: Disconnection/Ground fault Failure code [DF10KA] Travel speed range selector switch: Disconnection/Ground fault Action code Failure code Travel speed range selector switch: Disconnection/Ground fault Trouble (HST controller system) DF10KA...
Page 815 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DF10KA] Travel speed range selector switch: Disconnection/Ground fault Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between HST (female) (32) –...
Page 816 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DF10KA] Travel speed range selector switch: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-360...
Page 817: Failure Code [Df10Kb] Travel Speed Range Selector Switch: Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DF10KB] Travel speed range selector switch: Hot short Failure code [DF10KB] Travel speed range selector switch: Hot short Action code Failure code Travel speed range selector switch: Hot short Trouble (HST controller system) DF10KB...
Page 818 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DF10KB] Travel speed range selector switch: Hot short Causes Standard value in normal state/Remarks on troubleshooting Between wiring harness L03 (female) (2) – Voltage Max. 1 V L70 (female) (1) and ground Hot short (Contact with 24V Between wiring harness L03 (female) (4) –...
Page 819: Failure Code [Dgh1Kx] Hst Oil Temperature Sensor: Ground Fault
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DGH1KX] HST oil temperature sensor: Ground fault Failure code [DGH1KX] HST oil temperature sensor: Ground fault Action code Failure code HST oil temperature sensor: Ground fault Trouble (Machine monitor system) DGH1KX Contents of...
Page 820: Failure Code [Dgr2Kb] Brake Oil Temperature Sensor: Ground Fault
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DGR2KB] Brake oil temperature sensor: Ground fault Failure code [DGR2KB] Brake oil temperature sensor: Ground fault Action code Failure code Brake oil temperature sensor: Ground fault Trouble (Machine monitor system) DGR2KB Contents of...
Page 821: Failure Code [Dgr2Kz] Brake Oil Temperature Sensor: Disconnection/Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DGR2KZ] Brake oil temperature sensor: Disconnection/Hot short Failure code [DGR2KZ] Brake oil temperature sensor: Disconnection/ Hot short Action code Failure code Brake oil temperature sensor: Disconnection/Hot short Trouble (Machine monitor system) DGR2KZ...
Page 822 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DGR2KZ] Brake oil temperature sensor: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-360...
Page 823: Failure Code [Dhh1Kx] Hst Oil Pressure Sensor: Disconnection/Ground Fault
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DHH1KX] HST oil pressure sensor: Disconnection/Ground fault Failure code [DHH1KX] HST oil pressure sensor: Disconnection/Ground fault Action code Failure code HST oil pressure sensor: Disconnection/Ground fault Trouble (HST controller system) DHH1KX Contents of...
Page 824 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DHH1KX] HST oil pressure sensor: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-360...
Page 825: Failure Code [Dhh1Ky] Hst Oil Pressure Sensor: Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DHH1KY] HST oil pressure sensor: Hot short Failure code [DHH1KY] HST oil pressure sensor: Hot short Action code Failure code HST oil pressure sensor: Hot short Trouble (HST controller system) DHH1KY Contents of...
Page 826 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DHH1KY] HST oil pressure sensor: Hot short Related circuit diagram WA250, 250PZ-6 40-360...
Page 827: Failure Code [Dhtcl6] Hst Filter Clogging Sensor: Functional Defect
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DHTCL6] HST filter clogging sensor: Functional defect Failure code [DHTCL6] HST filter clogging sensor: Functional defect Action code Failure code HST filter clogging sensor: Functional defect Trouble (Machine monitor system) DHTCL6 Contents of...
Page 828 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DHTCL6] HST filter clogging sensor: Functional defect WA250, 250PZ-6 40-360...
Page 829: Failure Code [Djf1Ka] Fuel Level Sensor: Disconnection/Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DJF1KA] Fuel level sensor: Disconnection/Hot short Failure code [DJF1KA] Fuel level sensor: Disconnection/Hot short Action code Failure code Fuel level sensor: Disconnection/Hot short Trouble (Machine monitor system) DJF1KA Contents of •...
Page 830 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DJF1KA] Fuel level sensor: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-360...
Page 831: Failure Code [Dlt3Kx] Travel Speed Sensor B: Abnormality
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT3KX] Travel speed sensor B: Abnormality Failure code [DLT3KX] Travel speed sensor B: Abnormality Action code Failure code Travel speed sensor B: Abnormality Trouble (HST controller system) DLT3KX Contents of •...
Page 832 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT3KX] Travel speed sensor B: Abnormality Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then start engine and carry out troubleshooting without traveling. Voltage Possible causes Between (22) –...
Page 833 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT3KX] Travel speed sensor B: Abnormality When [DLT3KX] and [DLT4KX] (Travel speed sensor A: Abnormality) are turned ON simultaneously Contents of • While machine was traveling at speed above about 4 km/h, input signals of travel speed sensors A trouble and B were lost.
Page 834 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT3KX] Travel speed sensor B: Abnormality Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then start engine and carry out troubleshooting without traveling. Voltage Between (22) –...
Page 835: Failure Code [Dlt4Kx] Travel Speed Sensor A: Abnormality
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT4KX] Travel speed sensor A: Abnormality Failure code [DLT4KX] Travel speed sensor A: Abnormality Action code Failure code Travel speed sensor A: Abnormality Trouble (HST controller system) DLT4KX Contents of •...
Page 836 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT4KX] Travel speed sensor A: Abnormality Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then start engine and carry out troubleshooting without traveling. Voltage Possible causes Between (22) –...
Page 837: Failure Code [Dlt4Lc] Travel Speed Sensor A & B: Abnormality
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT4LC] Travel speed sensor A & B: Abnormality Failure code [DLT4LC] Travel speed sensor A & B: Abnormality Action code Failure code Travel speed sensor A & B: Abnormality Trouble (HST controller system) DLT4LC...
Page 838 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DLT4LC] Travel speed sensor A & B: Abnormality Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then start engine and carry out troubleshooting without traveling.
Page 839: Failure Code [Dv00Ky] Alarm Buzzer: Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DV00KY] Alarm buzzer: Hot short Failure code [DV00KY] Alarm buzzer: Hot short Action code Failure code Alarm buzzer: Hot short Trouble (Machine monitor system) DV00KY Contents of •...
Page 840 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DV00KY] Alarm buzzer: Hot short Related circuit diagram WA250, 250PZ-6 40-360...
Page 841: Failure Code [Dw26Ka] Motor 2 Solenoid: Disconnection/Ground Fault
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW26KA] Motor 2 solenoid: Disconnection/Ground fault Failure code [DW26KA] Motor 2 solenoid: Disconnection/Ground fault Action code Failure code Motor 2 solenoid: Disconnection/Ground fault Trouble (HST controller system) DW26KA Contents of •...
Page 842 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW26KA] Motor 2 solenoid: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-360...
Page 843: Failure Code [Dw26Ky] Motor 2 Solenoid: Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW26KY] Motor 2 solenoid: Hot short Failure code [DW26KY] Motor 2 solenoid: Hot short Action code Failure code Motor 2 solenoid: Hot short Trouble (HST controller system) DW26KY Contents of •...
Page 844 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW26KY] Motor 2 solenoid: Hot short Related circuit diagram WA250, 250PZ-6 40-360...
Page 845: Failure Code [Dw7Bky] Fan Reverse Solenoid Circuit: Hot Short
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW7BKY] Fan reverse solenoid circuit: Hot short Failure code [DW7BKY] Fan reverse solenoid circuit: Hot short Action code Failure code Fan reverse solenoid circuit: Hot short Trouble (HST controller system) DW7BKY Contents of...
Page 846 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW7BKY] Fan reverse solenoid circuit: Hot short Related circuit diagram WA250, 250PZ-6 40-360...
Page 847: Failure Code [Dw7Bkz] Fan Reverse Solenoid Circuit: Disconnection/Ground Fault
360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW7BKZ] Fan reverse solenoid circuit: Disconnection/Ground fault Failure code [DW7BKZ] Fan reverse solenoid circuit: Disconnection/ Ground fault Action code Failure code Fan reverse solenoid circuit: Disconnection/Ground fault Trouble (HST controller system) DW7BKZ...
Page 848 360 Troubleshooting by failure code (Display of code), Part 6 SEN03846-00 Failure code [DW7BKZ] Fan reverse solenoid circuit: Disconnection/Ground fault Related circuit diagram WA250, 250PZ-6 40-360...
Page 849 SEN03846-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03846-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-360...
Page 850: Troubleshooting By Failure Code (Display Of Code), Part
SEN03847-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 370 Troubleshooting by failure code (Display of code), Part 7 Failure code [DX16KA] Fan EPC solenoid: Disconnection ................2 Failure code [DX16KB] Fan EPC solenoid: Ground fault................3 Failure code [DX16KY] Fan EPC solenoid: Hot short ..................
Page 851: Failure Code [Dx16Ka] Fan Epc Solenoid: Disconnection
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX16KA] Fan EPC solenoid: Disconnection Failure code [DX16KA] Fan EPC solenoid: Disconnection Action code Failure code Fan EPC solenoid: Disconnection Trouble (HST controller system) DX16KA Contents of •...
Page 852: Failure Code [Dx16Kb] Fan Epc Solenoid: Ground Fault
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX16KB] Fan EPC solenoid: Ground fault Failure code [DX16KB] Fan EPC solenoid: Ground fault Action code Failure code Fan EPC solenoid: Ground fault Trouble (HST controller system) DX16KB Contents of •...
Page 853: Failure Code [Dx16Ky] Fan Epc Solenoid: Hot Short
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX16KY] Fan EPC solenoid: Hot short Failure code [DX16KY] Fan EPC solenoid: Hot short Action code Failure code Fan EPC solenoid: Hot short Trouble (HST controller system) DX16KY Contents of •...
Page 854 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX16KY] Fan EPC solenoid: Hot short WA250, 250PZ-6 40-370...
Page 855: Failure Code [Dx19Ka] Motor 1 Solenoid: Disconnection
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX19KA] Motor 1 solenoid: Disconnection Failure code [DX19KA] Motor 1 solenoid: Disconnection Action code Failure code Motor 1 solenoid: Disconnection Trouble (HST controller system) DX19KA Contents of •...
Page 856 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX19KA] Motor 1 solenoid: Disconnection Related circuit diagram WA250, 250PZ-6 40-370...
Page 857: Failure Code [Dx19Kb] Motor 1 Solenoid: Ground Fault
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX19KB] Motor 1 solenoid: Ground fault Failure code [DX19KB] Motor 1 solenoid: Ground fault Action code Failure code Motor 1 solenoid: Ground fault Trouble (HST controller system) DX19KB Contents of •...
Page 858 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX19KB] Motor 1 solenoid: Ground fault Related circuit diagram WA250, 250PZ-6 40-370...
Page 859: Failure Code [Dx19Ky] Motor 1 Solenoid: Hot Short
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX19KY] Motor 1 solenoid: Hot short Failure code [DX19KY] Motor 1 solenoid: Hot short Action code Failure code Motor 1 solenoid: Hot short Trouble (HST controller system) DX19KY Contents of •...
Page 860 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX19KY] Motor 1 solenoid: Hot short Related circuit diagram WA250, 250PZ-6 40-370...
Page 861: Failure Code [Dx20Ka] Clutch Epc Solenoid: Disconnection
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX20KA] Clutch EPC solenoid: Disconnection Failure code [DX20KA] Clutch EPC solenoid: Disconnection Action code Failure code Clutch EPC solenoid: Disconnection Trouble (HST controller system) DX20KA • Disconnection was detected in clutch EPC solenoid circuit. Contents of (When output command was above 250 mA, difference between command value and sensed cur- trouble...
Page 862 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX20KA] Clutch EPC solenoid: Disconnection Related circuit diagram WA250, 250PZ-6 40-370...
Page 863: Failure Code [Dx20Kb] Clutch Epc Solenoid: Ground Fault
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX20KB] Clutch EPC solenoid: Ground fault Failure code [DX20KB] Clutch EPC solenoid: Ground fault Action code Failure code Clutch EPC solenoid: Ground fault Trouble (HST controller system) DX20KB Contents of •...
Page 864 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX20KB] Clutch EPC solenoid: Ground fault Related circuit diagram WA250, 250PZ-6 40-370...
Page 865: Failure Code [Dx20Ky] Clutch Epc Solenoid: Hot Short
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX20KY] Clutch EPC solenoid: Hot short Failure code [DX20KY] Clutch EPC solenoid: Hot short Action code Failure code Clutch EPC solenoid: Hot short Trouble (HST controller system) DX20KY Contents of •...
Page 866 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DX20KY] Clutch EPC solenoid: Hot short Related circuit diagram WA250, 250PZ-6 40-370...
Page 867: Failure Code [Dxh7Kb] Reverse Solenoid: Ground Fault
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH7KB] Reverse solenoid: Ground fault Failure code [DXH7KB] Reverse solenoid: Ground fault Action code Failure code Reverse solenoid: Ground fault Trouble (HST controller system) DXH7KB Contents of •...
Page 868 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH7KB] Reverse solenoid: Ground fault Related circuit diagram WA250, 250PZ-6 40-370...
Page 869: Failure Code [Dxh7Kz] Reverse Solenoid: Disconnection/Hot Short
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH7KZ] Reverse solenoid: Disconnection/Hot short Failure code [DXH7KZ] Reverse solenoid: Disconnection/Hot short Action code Failure code Reverse solenoid: Disconnection/Hot short Trouble (HST controller system) DXH7KZ • Reverse solenoid is not turned ON (HST pressure selector relay does not operate) (when there is Contents of disconnection).
Page 870 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH7KZ] Reverse solenoid: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-370...
Page 871: Failure Code [Dxh8Kb] Forward Solenoid: Ground Fault
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH8KB] Forward solenoid: Ground fault Failure code [DXH8KB] Forward solenoid: Ground fault Action code Failure code Forward solenoid: Ground fault Trouble (HST controller system) DXH8KB Contents of •...
Page 872 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH8KB] Forward solenoid: Ground fault Related circuit diagram WA250, 250PZ-6 40-370...
Page 873: Failure Code [Dxh8Kz] Forward Solenoid: Disconnection/Hot Short
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH8KZ] Forward solenoid: Disconnection/Hot short Failure code [DXH8KZ] Forward solenoid: Disconnection/Hot short Action code Failure code Forward solenoid: Disconnection/Hot short Trouble (HST controller system) DXH8KZ • Forward solenoid is not turned ON (HST pressure selector relay does not operate) (when there is Contents of disconnection).
Page 874 370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [DXH8KZ] Forward solenoid: Disconnection/Hot short Related circuit diagram WA250, 250PZ-6 40-370...
Page 875: Failure Code [J141N1] Steering Pump: Overrun Alarm
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [J141N1] Steering pump: Overrun alarm Failure code [J141N1] Steering pump: Overrun alarm Action code Failure code Steering pump: Overrun alarm Trouble (HST controller system) J141N1 Contents of •...
Page 876: Failure Code [M400N1] Motor 1: Overrun Alarm
370 Troubleshooting by failure code (Display of code), Part 7 SEN03847-00 Failure code [M400N1] Motor 1: Overrun alarm Failure code [M400N1] Motor 1: Overrun alarm Action code Failure code Motor 1: Overrun alarm Trouble (HST controller system) M400N1 Contents of •...
Page 877 SEN03847-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03847-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-370...
Page 878 SEN03848-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 400 Troubleshooting of electrical system (E-mode) E-1 Engine does not start ..........................3 E-2. Preheater does not operate normally ....................10 E-3 Defective boom kick-out function and cancellation ................
Page 879 400 Troubleshooting of electrical system (E-mode) SEN03848-00 40-400 WA250, 250PZ-6...
Page 880: E-1 Engine Does Not Start
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start E-1 Engine does not start Contents of • The engine does not start. trouble • Before starting troubleshooting, check the following. a. Directional lever is not in N (Neutral). b.
Page 881 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting with- out turning starting switch ON. Defective directional L62 (male) Switch position Resistance switch (Internal defect)
Page 882 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF (with wiring harness connected), then carry out troubleshooting without turning starting switch ON. Starting motor safety relay Voltage Between B-terminal Power supply input...
Page 883 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting with- out turning starting switch ON. L79 (male) Resistance Between (1) and (2) 200 –...
Page 884 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start Causes Standard value in normal state/Remarks on troubleshooting Wiring harness between L107 (female) (2), L108 Resis- Max. 1 z (female) (2) – EC2 (female) (33) tance Disconnection in wiring Wiring harness between fuse No.
Page 885 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start Related circuit diagram 40-400 WA250, 250PZ-6...
Page 886 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-1 Engine does not start WA250, 250PZ-6 40-400...
Page 887: E-2. Preheater Does Not Operate Normally
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-2. Preheater does not operate normally E-2. Preheater does not operate normally a) Preheater does not operate Contents of • When temperature is low (engine boost air temperature is below –4°C), preheater does not operate. trouble •...
Page 888 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-2. Preheater does not operate normally Related circuit diagram WA250, 250PZ-6 40-400...
Page 889 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-2. Preheater does not operate normally b) Preheater operates constantly Contents of • Preheater operates constantly. trouble • If failure code [CA144] or [CA145] is displayed, carry out troubleshooting for it first. Related •...
Page 890 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-2. Preheater does not operate normally WA250, 250PZ-6 40-400...
Page 891: E-3 Defective Boom Kick-Out Function And Cancellation
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-3 Defective boom kick-out function and cancellation E-3 Defective boom kick-out function and cancellation Contents of • Boom kick-out does not function or cannot be cancelled due to defective boom kick-out proximity trouble switch system, lift arm PPC detent system and lift arm detent relay system.
Page 892 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-3 Defective boom kick-out function and cancellation Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between F04 (female) (A) Resis- Max.
Page 893 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-3 Defective boom kick-out function and cancellation Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON, raise lift arm to the highest position (kick-out operated), and carry Possible out troubleshooting.
Page 894 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-3 Defective boom kick-out function and cancellation Related circuit diagram WA250, 250PZ-6 40-400...
Page 895: E-4 Defective Bucket Positioner Function And Cancellation
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-4 Defective bucket positioner function and cancellation E-4 Defective bucket positioner function and cancellation Contents of • Bucket positioner does not function or cannot be cancelled due to defective bucket positioner proxim- trouble ity switch system, bucket PPC detent system and bucket detent relay system.
Page 896 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-4 Defective bucket positioner function and cancellation Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF. a Interchange bucket positioner proximity switch (F03) with lift arm positioner proximity switch (F04). a Operate bucket positioner with engine started.
Page 897 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-4 Defective bucket positioner function and cancellation Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between F03 (female) (B) – Resis- Min.
Page 898 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-4 Defective bucket positioner function and cancellation Related circuit diagram WA250, 250PZ-6 40-400...
Page 899: E-5 Defective Lift Arm Floating Holding Function And Cancellation
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-5 Defective lift arm FLOATING holding function and cancellation E-5 Defective lift arm FLOATING holding function and cancellation Contents of • Lift arm FLOATING holding does not function or cannot be cancelled due to defective lift arm FLOAT- trouble ING PPC detent system.
Page 900 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-5 Defective lift arm FLOATING holding function and cancellation Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between F04 (female) (A) Resis- Max.
Page 901 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-5 Defective lift arm FLOATING holding function and cancellation Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON, Possible operate lift arm FLOATING, and carry out troubleshooting. causes and Hot short-circuiting between Wiring harness between F04 (female) (B) –...
Page 902 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-5 Defective lift arm FLOATING holding function and cancellation Related circuit diagram WA250, 250PZ-6 40-400...
Page 903: E-6 Travel Direction Selection System Does Not Function
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-6 Travel direction selection system does not function E-6 Travel direction selection system does not function a) When parking brake is released, parking brake indicator of machine monitor keeps lighting. Contents of • Machine does not travel forward because of trouble in parking brake system, forward solenoid valve trouble system or directional lever system.
Page 904 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-6 Travel direction selection system does not function Related circuit diagram WA250, 250PZ-6 40-400...
Page 905 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-6 Travel direction selection system does not function b) When parking brake is released, parking brake indicator of machine monitor goes off but machine does not travel forward Contents of • Machine does not travel forward because of trouble in parking brake system, forward solenoid valve trouble system or directional lever system.
Page 906 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-6 Travel direction selection system does not function Related circuit diagram WA250, 250PZ-6 40-400...
Page 907: E-7 Wiper Does Not Operate
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-7 Wiper does not operate E-7 Wiper does not operate Contents of (1) Front wiper does not operate. trouble Related • The front wiper does not operate due to the defective front wiper switch, timer, or wiring harness. information Causes Standard value in normal state/Remarks on troubleshooting...
Page 908 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-7 Wiper does not operate Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between L05 (female) (3) – Resis- Max.
Page 909 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-7 Wiper does not operate Contents of (2) Rear wiper does not operate. trouble Related • Since the rear wiper switch or wiring harness is defective, the rear wiper does not operate. information Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON...
Page 910 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-7 Wiper does not operate Related circuit diagram WA250, 250PZ-6 40-400...
Page 911: E-8 Windshield Washer Does Not Operate
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-8 Windshield washer does not operate E-8 Windshield washer does not operate Contents of Windshield washer does not operate. trouble • Since the windshield washer motor, switch, timer (for only front), or wiring harness is defective, the Related windshield washer does not operate.
Page 912 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-8 Windshield washer does not operate Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Washer switch for Voltage front wiper Defective wiper timer (relay) Between (3) and...
Page 913 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-8 Windshield washer does not operate Related circuit diagram 40-400 WA250, 250PZ-6...
Page 914 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-8 Windshield washer does not operate WA250, 250PZ-6 40-400...
Page 915: E-9 Headlamp, Clearance Lamp And Tail Lamp Do Not Light Up Or Go Off
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Contents of (1) Headlamp, clearance lamp and tail lamp do not light up or go off. trouble •...
Page 916 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Contents of (2) Either of headlamp (low and high beams) does not light up or go off. trouble • The switch, lamp, or wiring harness of the headlamp (low and high beams) is defective. •...
Page 917 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between L04 (female) (2) –...
Page 918 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Contents of (3) Headlamp (low beam) does not light up or go off. trouble • The switch, lamp, or wiring harness of the headlamp (low beam) is disconnected or shorted with the ground.
Page 919 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Contents of (4) Headlamp (high beam) does not light up or go off. trouble • The switch, lamp, or wiring harness of the headlamp (high beam) is disconnected or shorted with the ground.
Page 920 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Contents of (5) Clearance lamp does not light up or go off. trouble (6) Tail lamp does not light up or go off. •...
Page 921 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between L04 (female) (1) –...
Page 922 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-9 Headlamp, clearance lamp and tail lamp do not light up or go off Related circuit diagram WA250, 250PZ-6 40-400...
Page 923: E-10 Working Lamp Does Not Light Up Or Go Off
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-10 Working lamp does not light up or go off E-10 Working lamp does not light up or go off Contents of (1) Front working lamp does not light up or go off. trouble •...
Page 924 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-10 Working lamp does not light up or go off Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between L07 (female) (5) –...
Page 925 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-10 Working lamp does not light up or go off Contents of (2) Rear working lamp does not light up or go off. trouble • The switch, lamp, or wiring harness of the rear working lamp system is defective. Related •...
Page 926 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-10 Working lamp does not light up or go off Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between L08 (female) (5) –...
Page 927 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-10 Working lamp does not light up or go off Related circuit diagram 40-400 WA250, 250PZ-6...
Page 928: E-11 Turn Signal Lamp And Hazard Lamp Do Not Light Up Or Go Off
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off E-11 Turn signal lamp and hazard lamp do not light up or go off Contents of (1) Either of turn signal lamp and hazard lamp does not light up or go off. trouble •...
Page 929 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between L125 (female) (3) –...
Page 930 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off Contents of (2) Turn signal lamp does not light up or go off. trouble • The switch, lamp, or wiring harness of the turn signal lamp system is defective. •...
Page 931 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off Contents of (3) Hazard lamp does not light up or go off. trouble Related • The switch or lamp of the hazard lamp is defective. information •...
Page 932 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between fuse No.
Page 933 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off Related circuit diagram 40-400 WA250, 250PZ-6...
Page 934 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-11 Turn signal lamp and hazard lamp do not light up or go off WA250, 250PZ-6 40-400...
Page 935: E-12 Brake Lamp Does Not Light Or It Keeps Lighting Up
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-12 Brake lamp does not light or it keeps lighting up E-12 Brake lamp does not light or it keeps lighting up Contents of Brake lamp does not light or it keeps lighting up. trouble Related •...
Page 936 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-12 Brake lamp does not light or it keeps lighting up Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Possible causes and Wiring harness between L34 (female) (2) –...
Page 937: E-13 Backup Lamp Does Not Light Or It Keeps Lighting Up
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-13 Backup lamp does not light or it keeps lighting up E-13 Backup lamp does not light or it keeps lighting up Contents of Backup lamp does not light or it keeps lighting up. trouble •...
Page 938 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-13 Backup lamp does not light or it keeps lighting up Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between fuse No.
Page 939 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-13 Backup lamp does not light or it keeps lighting up Related circuit diagram 40-400 WA250, 250PZ-6...
Page 940: E-14 Backup Alarm Does Not Sound Or It Keeps Sounding
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-14 Backup alarm does not sound or it keeps sounding E-14 Backup alarm does not sound or it keeps sounding Contents of Backup alarm does not sound or it keeps sounding. trouble • The machine monitor monitors the primary circuit of the backup lamp relay for a trouble. Related (If hot short occurs in the primary side of the back lamp relay, failure code [D160KY] is indicated.
Page 941 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-14 Backup alarm does not sound or it keeps sounding Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between fuse No.
Page 942 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-14 Backup alarm does not sound or it keeps sounding Related circuit diagram WA250, 250PZ-6 40-400...
Page 943: E-15 Horn Does Not Sound Or It Keeps Sounding
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-15 Horn does not sound or it keeps sounding E-15 Horn does not sound or it keeps sounding Contents of Horn does not sound or it keeps sounding. trouble Related — information Causes Standard value in normal state/Remarks on troubleshooting Defective fuse No.9 of fuse If the fuse is burn, the circuit probably has a grounding fault, etc.
Page 944 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-15 Horn does not sound or it keeps sounding Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then carry out troubleshooting without turning starting switch ON. Wiring harness between fuse No. 9 of fuse Resis- box (FS2) –...
Page 945: E-16 Alarm Buzzer Does Not Sound Or It Keeps Sounding
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-16 Alarm buzzer does not sound or it keeps sounding E-16 Alarm buzzer does not sound or it keeps sounding Contents of • Alarm buzzer does not sound or it keeps sounding. trouble •...
Page 946 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-16 Alarm buzzer does not sound or it keeps sounding Related circuit diagram WA250, 250PZ-6 40-400...
Page 947: E-17 Air Conditioner Does Not Operate Or Stop
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-17 Air conditioner does not operate or stop E-17 Air conditioner does not operate or stop Contents of Air conditioner does not operate or stop. trouble • The following is troubleshooting applicable only to the power supply and GND circuit between the air Related conditioner and operator's cab.
Page 948 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-17 Air conditioner does not operate or stop Causes Standard value in normal state/Remarks on troubleshooting a Prepare with starting switch OFF, then turn starting switch ON and carry out troubleshooting. Blower OFF relay, Starting switch Voltage pressure switch...
Page 949 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-17 Air conditioner does not operate or stop Related circuit diagram 40-400 WA250, 250PZ-6...
Page 950: E-18 The Komtrax System Does Not Work Properly
400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-18 The KOMTRAX system does not work properly E-18 The KOMTRAX system does not work properly Trouble • The KOMTRAX system does not work properly. • If the KOMTRAX system administrator asks you to check whether any defect occurs in the machine Related system, carry out the following troubleshooting.
Page 951 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-18 The KOMTRAX system does not work properly Cause Standard value in normal state/Remarks on troubleshooting a Turn the starting switch ON, and carry out troubleshooting. 6 Number of unsent mails LED (12) Normal state 7 segments 0 –...
Page 952 400 Troubleshooting of electrical system (E-mode) SEN03848-00 E-18 The KOMTRAX system does not work properly LED display L80 connector LED for communication module LED-A1 (power indicator lamp) LED-A2 (within communication range lamp) LED-A3 (on communicating lamp) LED-A4 (internal transmission lamp) LED-A5 (internal reception lamp) CPU LED LED-C1 (R signal and ACC signal status)
Page 953 SEN03848-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03848-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-400...
Page 954 SEN03849-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 500 Troubleshooting of hydraulic and mechanical system (H-mode) Method of using troubleshooting chart......................3 Failure code and cause table .......................... 6 H-1 The machine does not start........................
Page 955 500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-20 The bucket moves slowly or the tilting-back force is insufficient ............23 H-21 The bucket comes to operate slowly in the midst of tilting-back ............24 H-22 The bucket cylinder cannot hold down the bucket ................24 H-23 Hydraulic drifts of the bucket occur often .....................
Page 956: Method Of Using Troubleshooting Chart
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 Method of using troubleshooting chart Method of using troubleshooting chart This troubleshooting chart determines the location from the problem occurring on the machine and catego- rizes the problem under one of the main components, such as the steering system or work equipment hydraulic system.
Page 957 500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 Method of using troubleshooting chart Operate the machine and carry out trouble- Repeat the operation in Steps 3, 4, and 5 until the cause is narrowed down to 1 item (1 com- shooting of the items not checked in Step 1.
Page 958 500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 Method of using troubleshooting chart WA250, 250PZ-6 40-500...
Page 959: Failure Code And Cause Table
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 Failure code and cause table Failure code and cause table Part causing problem HST pump motor 2 motor 1 Failure Code Does not travel forward or in reverse Does not travel forward (reverse is normal) The machine does not start at reverse (Forward is normal) Speed is slow in both forward and reverse The travel speed is slow at forward (Reverse is normal)
Page 960 Clutch solenoid Clutch Transfer Work equipment and steering pump Brake pump Orbit-roll Priority valve Relief valve Safety valve Steering cylinder Tire inflation pressure Accumulator charge valve Brake valve Slack adjuster Brake disc and plate Brake piston Wheel brake linkage Main relief valve Lift arm spool Bucket spool Suction and safety valve...
Page 961: H-1 The Machine Does Not Start
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-1 The machine does not start H-1 The machine does not start Ask the operator about the following: Cause Has the machine come not start suddenly? Breakage of HST pump and motor related equipment Was there any problem of not traveling before? Internal wear of HST pump and motor related...
Page 962: H-2 The Travel Speed Is Slow
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-2 The travel speed is slow H-2 The travel speed is slow Ask the operator about the following: Cause Did the travel speed suddenly become HST pump HST motor 2 Others motor 1 slower? Breakage of HST pump and motor...
Page 963: H-3 The Traction Force Is Weak
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-3 The traction force is weak H-3 The traction force is weak When the travel speed is slow, carry out troubleshooting for Cause H-2 first. Others pump motor 2 motor 1 Remedy Diagnosis The traction force is weak in both forward and reverse...
Page 964: H-4 Engine Stalls When Traveling Or Engine Speed Drops Excessively
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-4 Engine stalls when traveling or engine speed drops excessively H-4 Engine stalls when traveling or engine speed drops excessively Ask the operator about the following: Cause Was there any problem before? Others Dirt in HST pump, motor related equipment pump...
Page 965: H-5 The Gear Is Not Shifted
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-5 The gear is not shifted H-5 The gear is not shifted If the speed range switch and the monitor display do not match, check Cause the electrical wiring. Others When the travel speed is slow, carry out troubleshooting for H-2 first. motor 2 motor 1 Remedy...
Page 966: H-6 The Steering Wheel Does Not Turn
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-6 The steering wheel does not turn H-6 The steering wheel does not turn Ask the operator about the following: Cause Did the problem suddenly start? Hydraulic Others Breakage of steering related equipment pump Was there previously any symptom, such as heavy steering? Internal wear of steering related equipment, defective seal...
Page 967: H-7 The Steering Wheel Is Heavy
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-7 The steering wheel is heavy H-7 The steering wheel is heavy Ask the operator about the following: Cause Did the problem suddenly start? Hydraulic Valve Others Breakage of steering related equipment pump Was there previously any symptom, such as heavy steering? Internal wear of steering related equipment, defective...
Page 968: H-8 Steering Wheel Shakes Or Jerks
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-8 Steering wheel shakes or jerks H-8 Steering wheel shakes or jerks Checks before troubleshooting Cause Is the hydraulic oil level correct? Is the type of oil correct? Valves Cylinder Valves Is there any play in the center hinge pin bearing or steering cylinder pin or bushing? Is there any variation in the tire inflation pressure?
Page 969: H-10 The Brake Does Not Work Or Does Not Work Well
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-10 The brake does not work or does not work well H-10 The brake does not work or does not work well Ask the operator about the following: Cause Has the brake come not to work suddenly? Breakage of brake equipment Has the brake come not to work gradually? Wear of lining and disc, defective seal...
Page 970: H-11 The Brake Is Not Released Or Is Dragged
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-11 The brake is not released or is dragged H-11 The brake is not released or is dragged Ask the operator about the following: Cause Has the brake pedal returned completely? Is the parking brake released completely? Check abnormality Abnormal heat of brake.
Page 971: H-12 The Lift Arm Does Not Rise Or Lower
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-12 The lift arm does not rise or lower H-12 The lift arm does not rise or lower Ask the operator about the following: Cause Has the lift arm come not to work suddenly? Work Priority Seizure or breakage of each equipment...
Page 972: H-13 The Lift Arm Moves Slowly Or The Lift Arm Rising Force Is Insufficient
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-13 The lift arm moves slowly or the lift arm rising force is insufficient H-13 The lift arm moves slowly or the lift arm rising force is insufficient Inspection before diagnosis Cause Is the stroke of the lift arm control lever appropri- Tank to...
Page 973: H-14 When Rising, The Lift Arm Comes To Move Slowly At Specific Height
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-14 When rising, the lift arm comes to move slowly at specific height H-14 When rising, the lift arm comes to move slowly at specific height Inspection before diagnosis Deformation of lift arm cylinder in appearance Cause Expansion of lift arm cylinder tube or damage inside For other abnormal phenomena during lift arm rise, see “H-13.
Page 974: When The Control Lever Is Switched From "Hold" To "Raise," The Lift Arm Falls Temporarily
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-18 When the control lever is switched from “HOLD” to “RAISE,” the lift arm falls temporarily H-18 When the control lever is switched from “HOLD” to “RAISE,” the lift arm falls temporarily Check of Phenomenon When the control lever is switched from “HOLD”...
Page 975: H-19 The Bucket Does Not Tilt Back
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-19 The bucket does not tilt back H-19 The bucket does not tilt back Ask the operator about the following: Cause Has the bucket come not to work suddenly Priority Work equip- Cylin- Tank to Pump Seizure or breakage of each equip-...
Page 976: H-20 The Bucket Moves Slowly Or The Tilting-Back Force Is Insufficient
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-20 The bucket moves slowly or the tilting-back force is insufficient H-20 The bucket moves slowly or the tilting-back force is insufficient Inspection before diagnosis Cause Is the stroke of the bucket control lever Tank to Priority Work equipment valve Cylinder...
Page 977: H-21 The Bucket Comes To Operate Slowly In The Midst Of Tilting-Back
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-21 The bucket comes to operate slowly in the midst of tilting-back H-21 The bucket comes to operate slowly in the midst of tilting-back Inspection before diagnosis Deformation of bucket cylinder in appearance Cause Expansion of bucket cylinder tube or damage inside For other abnormal phenomena during bucket operation, see “H-20.
Page 978: When The Control Lever Is Switched From "Hold" To "Tilt," The Bucket Falls Temporarily
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-25 When the control lever is switched from “HOLD” to “TILT,” the bucket falls temporarily H-25 When the control lever is switched from “HOLD” to “TILT,” the bucket falls temporarily Check of Phenomenon When the control lever is switched from “HOLD”...
Page 979: H-27 The Ecss Does Not Operate And Machine Pitches And Bounces
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-27 The ECSS does not operate and machine pitches and bounces H-27 The ECSS does not operate and machine pitches and bounces Check the following points with the operator. Cause Did the machine starts pitching and bouncing sud- Solenoid Accumulator Controller...
Page 980: Fan Revolution Is Abnormal (Fan Sound/Vibration Is Abnormally Large Or Engine Overheats)
500 Troubleshooting of hydraulic and mechanical system (H-mode) SEN03849-00 H-28 Fan revolution is abnormal (Fan sound/vibration is abnormally large or engine overheats) H-28 Fan revolution is abnormal (Fan sound/vibration is abnormally large or engine overheats) Check the following with the operator. Cause Did the fan start making the abnormal sound sud- Tank to...
Page 981 SEN03849-00 WA250-6, WA250PZ-6 GALEO Wheel loader Form No. SEN03849-00 ©2007 KOMATSU All Rights Reserved Printed in Japan 09-07 (01) 40-500...
Page 982 SEN03850-00 WHEEL LOADER WA250-6 WA250PZ-6 Machine model Serial number WA250-6 75001 and up WA250PZ-6 75001 and up 40 Troubleshooting 600 Troubleshooting of engine (S-mode) Method of using troubleshooting charts ......................2 S-1 Starting performance is poor ........................6 S-2 Engine does not start ..........................7 S-3 Engine does not pick up smoothly......................
Page 983: Method Of Using Troubleshooting Charts
600 Troubleshooting of engine (S-mode) SEN03850-00 Method of using troubleshooting charts Method of using troubleshooting charts The troubleshooting chart consists of the “ques- tions”, “check items”, “causes”, and “troubleshoot- ing” blocks. The questions and check items are used to pinpoint high probability causes by simple inspection or from phenomena without using troubleshooting tools.
Page 984 600 Troubleshooting of engine (S-mode) SEN03850-00 Method of using troubleshooting charts Items listed in the [Questions] and [Check items] and related to the [Causes] are marked with E, Q, or w. E : Causes to be referred to for questions and check items Q : Causes related to questions and check items w : Causes highly probable among ones marked with Q When narrowing the “causes“, apply the items marked with w before those marked with Q.
Page 985 600 Troubleshooting of engine (S-mode) SEN03850-00 Method of using troubleshooting charts <Example of troubleshooting> Exhaust gas is black Let us assume that [Clogged air cleaner] is taken to be the cause of black exhaust gas. 3 symptoms have causal relationship with this problem: [Color of exhaust gas gradually became black], [Power was lost gradu- ally], and [Air cleaner clogging caution lamp is flashing].
Page 986 600 Troubleshooting of engine (S-mode) SEN03850-00 Method of using troubleshooting charts If we look from these 3 symptoms to find the causes, we find that there is a relationship with 5 causes. Let us explain here the method of using this causal relationship to pinpoint the most probable cause. WA250, 250PZ-6 40-600...
Page 987: S-1 Starting Performance Is Poor
600 Troubleshooting of engine (S-mode) SEN03850-00 S-1 Starting performance is poor S-1 Starting performance is poor General causes why starting performance is poor Causes Defective electrical system Insufficient supply of fuel Insufficient intake of air Improper selection of fuel The common rail fuel injection system (CRI) controls the fuel injection timing electrically.
Page 988: S-2 Engine Does Not Start
600 Troubleshooting of engine (S-mode) SEN03850-00 S-2 Engine does not start S-2 Engine does not start a) Engine does not turn Causes General causes why engine does not turn Seized parts inside engine o See “S-4 Engine stops during operations” Defective electrical system Problem in drive devices on applicable machine side o Carry out troubleshooting for devices on applicable machine...
Page 989 600 Troubleshooting of engine (S-mode) SEN03850-00 S-2 Engine does not start b) Engine turns but no exhaust smoke comes out Causes General causes why engine turns but no exhaust smoke comes Fuel is not being supplied Supply of fuel is extremely small Improper selection of fuel (particularly in winter) Confirm recent repair history Degree of use of machine...
Page 990 600 Troubleshooting of engine (S-mode) SEN03850-00 S-2 Engine does not start c) Exhaust smoke comes out but engine does not start Causes (fuel is being injected) General causes why exhaust smoke comes out but engine does not start Lack of rotating force due to defective electrical system Insufficient supply of fuel Insufficient intake of air Improper selection of fuel...
Page 991: S-3 Engine Does Not Pick Up Smoothly
600 Troubleshooting of engine (S-mode) SEN03850-00 S-3 Engine does not pick up smoothly S-3 Engine does not pick up smoothly General causes why engine does not pick up smoothly Causes Insufficient intake of air Insufficient supply of fuel Defective condition of fuel injection Improper selection of fuel Controller is controlling in derate mode (limiting injection rate (output) because of an error in electrical system)
Page 992: S-4 Engine Stops During Operations
600 Troubleshooting of engine (S-mode) SEN03850-00 S-4 Engine stops during operations S-4 Engine stops during operations General causes why engine stops during operations Causes Internal parts of engine seized Insufficient supply of fuel There is overheating Problem in hydraulic pump Confirm recent repair history Degree of use of machine Operated for long period...
Page 993: S-5 Engine Does Not Rotate Smoothly
600 Troubleshooting of engine (S-mode) SEN03850-00 S-5 Engine does not rotate smoothly S-5 Engine does not rotate smoothly General causes why engine does not rotate smoothly Causes Air in fuel system Defective speed sensor (Error at degree that it is not indicated) Confirm recent repair history Degree of use of machine Operated for long period...
Page 994: Engine Lacks Output (Or Lacks Power)
600 Troubleshooting of engine (S-mode) SEN03850-00 S-6 Engine lacks output (or lacks power) S-6 Engine lacks output (or lacks power) General causes why engine lacks output Causes Insufficient intake of air Insufficient supply of fuel Defective condition of fuel injection Improper selection of fuel There is overheating o See “S-14 Coolant temperature becomes too...
Page 995: Exhaust Smoke Is Black (Incomplete Combustion)
600 Troubleshooting of engine (S-mode) SEN03850-00 S-7 Exhaust smoke is black (incomplete combustion) S-7 Exhaust smoke is black (incomplete combustion) General causes why exhaust smoke is black Causes Insufficient intake of air Defective condition of fuel injection Improper selection of fuel There is overheating o See “S-14 Coolant temperature becomes too high (Overheating)“...
Page 996: Oil Consumption Is Excessive (Or Exhaust Smoke Is Blue)
600 Troubleshooting of engine (S-mode) SEN03850-00 S-8 Oil consumption is excessive (or exhaust smoke is blue) S-8 Oil consumption is excessive (or exhaust smoke is blue) General causes why oil consumption is excessive Causes Abnormal consumption of oil Long-time operation of engine at low idle or high idle (Do not run engine at idle for more than 20 minutes continuously) External leakage of oil...
Page 997: S-9 Oil Becomes Contaminated Quickly
600 Troubleshooting of engine (S-mode) SEN03850-00 S-9 Oil becomes contaminated quickly S-9 Oil becomes contaminated quickly General causes why oil becomes contaminated quickly Causes Entry of exhaust gas into oil due to internal wear Clogging of lubrication passage Use of improper fuel Use of improper oil Operation under excessive load Confirm recent repair history...
Page 998: S-10 Fuel Consumption Is Excessive
600 Troubleshooting of engine (S-mode) SEN03850-00 S-10 Fuel consumption is excessive S-10 Fuel consumption is excessive General causes why fuel consumption is excessive Causes Leakage of fuel Defective condition of fuel injection (fuel pressure, injection timing) Excessive injection of fuel Confirm recent repair history Degree of use of machine Operated for long period...
Page 999: Oil Is In Coolant (Or Coolant Spurts Back Or Coolant Level Goes Down)
600 Troubleshooting of engine (S-mode) SEN03850-00 S-11 Oil is in coolant (or coolant spurts back or coolant level goes down) S-11 Oil is in coolant (or coolant spurts back or coolant level goes down) General causes why oil is in coolant Causes Internal leakage in lubrication system Internal leakage in cooling system...
Page 1000: S-12 Oil Pressure Drops
600 Troubleshooting of engine (S-mode) SEN03850-00 S-12 Oil pressure drops S-12 Oil pressure drops General causes why oil pressure drops Causes Leakage, clogging, wear of lubrication system Defective oil pressure control Improper selection of oil (improper viscosity) Deterioration of oil due to overheating Confirm recent repair history Degree of use of machine Operated for long period...

This manual is also suitable for:

Wa250pz-6 75001

Save PDF