Kohler Command PRO EFI Series Service Manual
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Kohler Command PRO EFI Series Service Manual

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ECV940 & ECV980
Service Manual
IMPORTANT:
Read all safety precautions and instructions carefully before operating equipment. Refer to operating
instruction of equipment that this engine powers.
Ensure engine is stopped and level before performing any maintenance or service.
2
Safety
3
5
Specifi cations
17
20
Troubleshooting
24
25
Electronic Fuel Injection (EFI) System
54
Governor System
80
82
87
91
112
Reassembly
62 690 05 Rev. E
KohlerEngines.com
1

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Summary of Contents for Kohler Command PRO EFI Series

  • Page 1 ECV940 & ECV980 Service Manual IMPORTANT: Read all safety precautions and instructions carefully before operating equipment. Refer to operating instruction of equipment that this engine powers. Ensure engine is stopped and level before performing any maintenance or service. Safety Maintenance Specifi...
  • Page 2 Safety SAFETY PRECAUTIONS WARNING: A hazard that could result in death, serious injury, or substantial property damage. CAUTION: A hazard that could result in minor personal injury or property damage. NOTE: is used to notify people of important installation, operation, or maintenance information. CAUTION WARNING WARNING...
  • Page 3 Perform these procedures more frequently under severe, dusty, dirty conditions. REPAIRS/SERVICE PARTS Kohler genuine service parts can be purchased from Kohler authorized dealers. To fi nd a local Kohler authorized dealer visit KohlerEngines.com or call 1-800-544-2444 (U.S. and Canada). 62 690 05 Rev. E...
  • Page 4 OIL RECOMMENDATIONS STORAGE If engine will be out of service for 2 months or more We recommend use of Kohler oils for best performance. follow procedure below. Other high-quality detergent oils (including synthetic) of API (American Petroleum Institute) service class SJ 1.
  • Page 5 Specifi cations Engine Dimensions - Flywheel Side 503.4 mm (19.82 in.) 484.6 mm (19.08 in.) Air Filter Element 267.4 mm (10.53 in.) 152.5 mm (6.00 in.) Removal 30.0 mm (1.18 in.) 17.3 mm (0.68 in.) 99.6 mm (3.92 in.) Cylinder #1 Shroud Cylinder #1 Shroud Spark Plug Lead Removal...
  • Page 6 Specifi cations Engine Dimensions - PTO Side (Earlier Design) 428.1 mm (16.86 in.) 45° 55° 35° 2X Ø 35 mm (1.38 in.) 60 mm (2.36 in.) M8 X 1.25 mm Ø 254.0 mm (10.0 in.) Muffl er Gasket Exhaust Port #2 4 Studs M8 X 1.25-6H 25 mm (0.98 in.) Deep 7...
  • Page 7 Specifi cations Engine Dimensions - PTO Side (Later Design) 2X Ø 35 mm (1.38 in.) 428.1 mm (16.86 in.) 45° 35° Muffl er Gasket 3/8-16 UNF-2B Inch 60 mm (2.36 in.) M8 X 1.25 mm Ø 254.0 mm (10.0 30 mm (1.18 in.) Exhaust Port #2 4 Studs in.)
  • Page 8 Specifi cations Engine Dimensions - Starter Side 93.5 mm (3.68 in.) Engine Mounting 680.8 mm (26.80 in.) Oil Pressure Switch Exhaust Port #1 Surface 7/16-20 UNF-2B Inch 6.4 mm (0.25 in.) 80.2 mm (3.16 in.) 38.1 mm (1.50 in.) Ø 28.6 mm (1.13 in.) Square Keyway Deep 156.2 mm (6.15 in.)
  • Page 9 Specifi cations Engine Dimensions - Opposite Starter Side 156.2 mm (6.15 in.) Lifting Point Cylinder #2 Shroud Access to Oil Cooler Cylinder #2 Shroud Removal Fuel Filter 70.5 mm (2.78 in.) Lifting Point Fits 6.4 mm (0.25 in.) Mounting Hole "A" Exhaust Port #2 Fuel Line Oil Drain Plug...
  • Page 10 Lubricate threads with engine oil prior to assembly. Any and all horsepower (hp) references by Kohler are Certifi ed Power Ratings and per SAE J1940 & J1995 hp standards. Details on Certifi ed Power Ratings can be found at KohlerEngines.com.
  • Page 11 Specifi cations TORQUE SPECIFICATIONS ECV940 ECV980 Connecting Rod Cap Fastener (torque in increments) 11.6 N·m (103 in. lb.) Crankcase Breather Cover Fastener 12.4 N·m (110 in. lb.) Oil Drain Plug 21.4 N·m (16 ft. lb.) Oil Temperature Sensor 7.3 N·m (65 in. lb.) Dipstick Tube Screw 7.7 N·m (68 in.
  • Page 12 Specifi cations TORQUE SPECIFICATIONS ECV940 ECV980 Igniton Continued Crankshaft Position Sensor Earlier Design Bracket Crankshaft Position Sensor to Bracket Screw 11.3 N·m (100 in. lb.) Crankshaft Position Sensor Bracket to Crankcase Screw 9.7 N·m (86 in. lb.) Crankshaft Position Sensor Later Design Bracket Crankshaft Position Sensor to Bracket Screw 6.8 N·m (60 in.
  • Page 13 Specifi cations TORQUE SPECIFICATIONS ECV940 ECV980 Starter Assembly Thru Bolt 5.6-9.0 N·m (49-79 in. lb.) Mounting Screw 16 N·m (142 in. lb.) Brush Holder Mounting Screw 2.5-3.3 N·m (22-29 in. lb.) Stator Mounting Screw 9.3 N·m (82 in. lb.) Throttle Control Bracket Fastener 9.9 N·m (88 in.
  • Page 14 Specifi cations CLEARANCE SPECIFICATIONS ECV940 ECV980 Crankshaft Continued Bore (in crankcase) 45.043/45.068 mm (1.7733/1.7743 in.) Crankshaft Bore (in crankcase)-to-Crankshaft Running Clearance 0.043/0.090 mm (0.0017/0.0035 in.) Bore (in oil pan) New, Without Bearing 50.025/50.00 mm (1.9694/1.9685 in.) Crankshaft to Sleeve Bearing (in oil pan) Running Clearance 0.040/0.167 mm (0.0015/0.0065 in.) Oil Pan End Main Bearing Journal O.D.
  • Page 15 Specifi cations CLEARANCE SPECIFICATIONS ECV940 ECV980 Ignition Spark Plug Gap 0.76 mm (0.030 in.) Crankshaft Position Sensor Air Gap (only on earlier design sensor 0.2/0.7 mm (0.008/0.027 in.) bracket) Crankshaft Position Sensor Max. Air Gap (only on later design 2.794 mm (0.110 in.) sensor bracket) Piston, Piston Rings, and Piston Pin Piston-to-Piston Pin Running Clearance...
  • Page 16 Specifi cations GENERAL TORQUE VALUES English Fastener Torque Recommendations for Standard Applications Bolts, Screws, Nuts and Fasteners Assembled Into Cast Iron or Steel Grade 2 or 5 Fasteners Into Aluminum Size Grade 2 Grade 5 Grade 8 Tightening Torque: N·m (in. lb.) ± 20% 8-32 2.3 (20) 2.8 (25)
  • Page 17 Shrader Valve Adapter Hose DTI-037 Wire Probe Set (2 pieces regular wire with clip; 1 piece fused wire) DTI-031 Hose Removal Tool, Dual Size/End (also sold as individual Kohler tool) DTI-033 K-Line Adapter Jumper Lead Wiring Harness Kohler 25 176 23-S Kohler Wireless Diagnostic System Module (Bluetooth®)
  • Page 18 For reaming worn valve guides to accept replacement oversize valves. Can be used in low-speed drill press or with handle below for hand reaming. Reamer Handle Design Technology Inc. For hand reaming using Kohler 25 455 12-S reamer. DTI-K830 KohlerEngines.com 62 690 05 Rev. E...
  • Page 19 Dielectric Grease (GE/Novaguard G661) Kohler 25 357 11-S Dielectric Grease Loctite ® 51360 Kohler Electric Starter Drive Lubricant (Inertia Drive) Kohler 52 357 01-S Kohler Electric Starter Drive Lubricant (Solenoid Shift) Kohler 52 357 02-S RTV Silicone Sealant Loctite ®...

  • Page 20: Troubleshooting

    Troubleshooting TROUBLESHOOTING GUIDE When troubles occur, be sure to check simple causes which, at fi rst, may seem too obvious to be considered. For example, a starting problem could be caused by an empty fuel tank. Some general common causes of EFI engine troubles are listed below and vary by engine specifi cation. Use these to locate causing factors.
  • Page 21 Troubleshooting EXTERNAL ENGINE INSPECTION Engine Loses Power NOTE: It is good practice to drain oil at a location away ● Dirty air cleaner element. from workbench. Be sure to allow ample time for ● Engine overheated. complete drainage. ● Excessive engine load. ●...
  • Page 22 Troubleshooting CRANKCASE VACUUM TEST WARNING WARNING Carbon Monoxide can cause severe nausea, Rotating Parts can cause severe injury. fainting or death. Stay away while engine is in operation. Avoid inhaling exhaust fumes. Never run engine indoors or in enclosed spaces. Keep hands, feet, hair, and clothing away from all Engine exhaust gases contain poisonous carbon moving parts to prevent injury.
  • Page 23 Troubleshooting COMPRESSION TEST A compression test is best performed on a warm engine. Clean any dirt or debris away from base of spark plug before removing it. Be sure battery is fully charged, unplug ECU, and throttle is wide open during test. Compression should be at least 160 psi and should not vary more than 15% between cylinders.
  • Page 24 Air Cleaner/Intake AIR CLEANER BREATHER TUBE These systems are CARB/EPA certifi ed and components Ensure both ends of breather tube are properly should not be altered or modifi ed in any way. connected. AIR COOLING WARNING Hot Parts can cause severe burns. Do not touch engine while operating or just after stopping.
  • Page 25 FUEL LINE ratio is required and system operates in an open loop Low permeation fuel line must be installed on all Kohler mode. In open loop operation oxygen sensor output is Co. engines to maintain EPA and CARB regulatory used to ensure engine is running rich, and controlling compliance.
  • Page 26 EFI SYSTEM ECU compares input signals to programmed maps in Crankshaft Position Sensor Bracket its memory to determine appropriate fuel and spark requirements for immediate operating conditions. ECU then sends output signals to set injector duration and ignition timing. ECU continually performs a diagnostic check of itself, each of sensors, and system performance.
  • Page 27 EFI SYSTEM Earlier engines have a separate intake air temperature Fuel injectors mount into intake manifold, and high (IAT) sensor (located in throttle body) and a manifold pressure fuel line attaches to them at top end. absolute pressure (MAP) sensor. Later engines have Replaceable O-rings on both ends of injector prevent a combined temperature/manifold absolute pressure external fuel leakage and also insulate it from heat and...
  • Page 28 EFI SYSTEM When key switch is turned ON and all safety switch For starting and warm up, ECU will adjust fuel and requirements are met, ECU activates fuel pump module ignition timing, based upon ambient temperature, engine for about six seconds, which pressurizes system for temperature, and loads present.
  • Page 29 EFI SYSTEM ELECTRICAL COMPONENTS Grey Connector Side Electronic Control Unit (ECU) Pin # Description Pinout of ECU Not Used Black Connector Side Not Used Pin # Function Malfunction Indicator Light (MIL) Ground Ignition Coil #1 Ground Not Used Battery Ground Not Used Diagnostic Communication Line GCU Tach Output (Electronic Governor)
  • Page 30 ECU Reset Procedure 1. Turn key/ignition OFF. 2. Install Red wire jumper from Kohler EFI service kit on to service port (connect white wire to black wire in 4 way diagnostic port). 3. Turn key/ignition ON, then OFF and count 10 seconds.
  • Page 31 EFI SYSTEM 62 690 05 Rev. E KohlerEngines.com...
  • Page 32 EFI SYSTEM KohlerEngines.com 62 690 05 Rev. E...
  • Page 33 EFI SYSTEM 62 690 05 Rev. E KohlerEngines.com...
  • Page 34 EFI SYSTEM Contacting (Brush) Type TPS Crankshaft Position Sensor Resistance Table Throttle Between Resistance Continuity Position Terminal Value (Ω) Closed A & C 1400-1800 Full with A & C 3200-4100 Stop Pin Full without A & C 4600-5200 Stop Pin A &...
  • Page 35 EFI SYSTEM Contactless (Magnet) Type TPS Replace magnet assembly TPS is a sealed, non-serviceable assembly. If diagnosis indicates a bad sensor, complete replacement is necessary. Magnet that sensor detects is separate, and can be replaced or reused. If a blink code indicates a problem with TPS, it can be tested as follows: Diagnostics of sensor: ECU will still have electrical faults captured in fault codes: P0122 &...
  • Page 36 EFI SYSTEM Engine (Oil) Temperature Sensor Manifold Absolute Pressure Sensor (MAP) A sealed, non-serviceable assembly. A faulty sensor A sealed, non-serviceable assembly. A faulty sensor must be replaced. If a blink code indicates a problem must be replaced. If a blink code indicates a problem with temperature sensor, it can be tested as follows: with manifold absolute pressure sensor, it can be tested as follows:...
  • Page 37 EFI SYSTEM 6. Check circuits (input, ground), from main harness Cutaway Oxygen Sensor Components (02) connector to sensor plug for continuity, damage, etc. Connect one ohmmeter lead to Black pin 8 in main harness connector (as in step 4). Connect other lead to terminal #3 in sensor plug.
  • Page 38 EFI SYSTEM Visual Inspection Sensor Signal Observation Engine Harness O2 Sensor Connector Plug Detail Sensor Wire Detail Red w/Black Stripe Dark Green Purple Black A Keep a minimum of 25 mm (1.0 in.) radius at NOTE: Do not cut into or pierce sensor or engine grommet.
  • Page 39 EFI SYSTEM Removal Inspection NOTE: Apply anti-seize compound only to threads. Anti-seize compound will aff ect sensor performance if it gets into lower shield of sensor. 1. If sensor has heavy deposits on lower shield, engine, oil, or fuel may be source. 2.
  • Page 40 EFI SYSTEM 1. With engine running at idle, listen for a buzzing or Fuel Injectors clicking sound. 2. Disconnect electrical connector from an injector and WARNING listen for a change in idle performance (only running Explosive Fuel can cause fi res and severe on one cylinder) or a change in injector noise or burns.
  • Page 41 NOTE: If ignition coil(s) are disabled and an ignition pump module and insert pressure test jumper (from fault is registered, system will automatically Kohler EFI Service Kit) between high pressure fuel disable corresponding fuel injector drive line and fuel pump module.
  • Page 42 Please note vent hose routing and replicate after service or component replacement to prevent pinching or abrasion of vent hoses. Only Kohler replacement parts can be used because fi tting is specifi c to system and must be maintained. Visit KohlerEngines.com for recommended Kohler replacement parts.
  • Page 43 EFI SYSTEM Troubleshooting Guide Condition Possible Cause Faulty spark plugs. Fuel pump not running. Fuel pressure low. Insuffi cient fuel delivery. Engine Starts Hard or Fails to Start TPS set incorrect (ECU Reset and TPS Initialization). When Hot. Crankshaft position sensor loose or faulty. TPS faulty.
  • Page 44 EFI SYSTEM Function Test Fault Codes Example of Diagnostic Display WARNING High Pressure Fluids can puncture skin and cause severe injury or death. One second pause Do not work on fuel system without proper Fault training or safety equipment. Code One second pause Fluid puncture injuries are highly toxic and hazardous.
  • Page 45 EFI SYSTEM Fault Code Connection or Failure Description 0230 Fuel Pump Module Circuit Low Voltage or Open 0232 Fuel Pump Module Circuit High Voltage 0336 Crankshaft Position Sensor Noisy Signal 0337 Crankshaft Position Sensor No Signal 0351 Cylinder 1 Ignition Coil Malfunction 0352 Cylinder 2 Ignition Coil Malfunction 0562...
  • Page 46 EFI SYSTEM Code 0032 Code 0108 NOTE: Codes 0031 and 0032 may have been Component: Manifold Absolute Pressure (MAP or mistakenly activated by turning key ON with TMAP) Sensor oxygen sensor disconnected. If either code Fault: MAP or TMAP Circuit High Voltage status is historic, that code may have set during assembly or a previous repair and may not be Condition:...
  • Page 47 EFI SYSTEM Code 0117 Code 0122 Component: Coolant/Oil Sensor Component: Throttle Position Sensor (TPS) Fault: Coolant/Oil Temperature Sensor Circuit Fault: TPS Circuit Low Voltage or Open Low Voltage Condition: Open connection, broken wire or faulty Condition: Shorted connection, faulty sensor or sensor.
  • Page 48 EFI SYSTEM Code 0131 Code 0171 Component: Oxygen Sensor Component: Fuel System Fault: O2S 1 Circuit Low Voltage Fault: Maximum adaptation limit exceeded Condition: Open connection, broken wire or faulty Condition: Fuel inlet screen/fi lter plugged, low sensor. pressure at high pressure fuel line, TPS malfunction, shorted connection, faulty Conclusion: Oxygen Sensor Related sensor, low fuel or wrong fuel type.
  • Page 49 EFI SYSTEM Code 0172 Code 0174 Component: Fuel System Component: Fuel System Fault: Minimum adaptation limit exceeded Fault: Lean fuel condition Condition: Too high pressure at high pressure fuel Condition: Fuel inlet screen/fi lter plugged, low line, TPS malfunction, shorted pressure at high pressure fuel line, TPS connection, faulty sensor or fuel pump malfunction, shorted connection or faulty...
  • Page 50 EFI SYSTEM Code 0202 Code 0336 Component: Fuel Injector Component: Crankshaft Position Sensor Fault: Injector 2 Circuit Malfunction Fault: Crankshaft Position Sensor Noisy Signal Condition: Injector damaged or faulty, shorted or Condition: Air gap incorrect, loose sensor, faulty/bad open connection. battery, shorted or faulty connection, faulty sensor or faulty sensor grounding.
  • Page 51 EFI SYSTEM Code 0351 Code 1693 Component: Ignition Coil Component: Tach Output (ECU) Fault: Cylinder 1 Ignition Coil Malfunction Fault: Tach Circuit Low Condition: Broken wire in harness (may not be Condition: Tachometer output circuit short to ground. visible), shorted connection or faulty Conclusion: Bad Tach Wire (grounded).
  • Page 52 EFI SYSTEM EFI Diagnostic Flow Diagram START OF TEST PROCEED TO START OF TEST FOR RETEST KEY ON MALFUNCTION REFER TO DIAGNOSTIC AID #1 INDICATOR LIGHT SYSTEM POWER REFER TO ARE FAULT CODES DIAGNOSTIC FAULT CODE SUMMARY PRESENT? CLEAR CODES REFER TO DIAGNOSTIC AID #3 DOES ENGINE START? MIL GOES OFF?
  • Page 53 ● Plug wire supply to bulb will be part of vehicle wire ● Coil harness. Kohler key switch model will have MIL ● Coil circuit(s), pin circuits Grey 10 and Black 1. on engine with 12V supply to bulb. ● ECU grounds ●...

  • Page 54: Governor System

    Governor System GOVERNOR These engines are equipped with an electronic governor or a mechanical governor. ELECTRONIC GOVERNOR NOTE: Actual speeds depend on application. Refer to equipment manufacturer’s recommendations. Electronic Governor System Designs Potentiometer Specifi cations As of this revision, there is an original design, a fi eld Speed Input Voltage Engine Speed (RPM) installed updated design, and a new updated design.
  • Page 55 Governor System Proper link/spring assembly is critical. Insert spring Operation of Electronic Governor System hook tab of spring through DLA clevis hole until it exits 1. Key is turned ON, providing power to GCU (red lead opposite side, and tab of spring is allowed to snap into from engine harness to GCU harness).
  • Page 56 Governor System Electronic Governor System Designs Field Installed Updated Design As of this revision, there is an original design, a fi eld installed updated design, and a new updated design. All designs function in same manner, and both updated designs have a non-serviceable electrical connection with a sealed (bonded) GCU module wiring harness assembly.
  • Page 57 Governor System New Updated Design New Sealed (Bonded) GCU Module New Updated Design Wiring Harness Assembly 4 Pin GCU to Main Speed Control Input Engine Harness New Updated Design features a sealed (bonded) GCU module wiring harness assembly that must NOT be separated.
  • Page 58 Governor System ORIGINAL DESIGN GCU/Harness Diagnostics and Troubleshooting NOTE: It is important to use proper sized probes to perform these tests. Probes that are incorrect size can damage connector or harness plug. Original design features a separate GCU and wiring harness that can be separated and tested for power and ground.
  • Page 59 Governor System ORIGINAL DESIGN Speed Control Input ORIGINAL DESIGN GCU Blink Code Tests Green LED Light Yellow LED Light Speed control issues can also be diagnosed utilizing on-board Blink Code diagnostic lights equipped in GCU. These GCUs store blink codes/trouble codes, that can be quickly diagnosed using blink code charts.
  • Page 60 Governor System ORIGINAL DESIGN GCU Blink Codes for Software Running Codes - Activated when engine is running. Response LED Diagnostics Failure Condition Possible Causes Response Time Yellow LED Green LED Running Normally None BLINKS BLINKS RPM Too High Mechanical bindage None BLINKS RPM Too Low...
  • Page 61 Governor System ORIGINAL DESIGN Troubleshooting Electronic Governor Failure Condition Possible Causes Equipment Observations Inspection/Testing Target/Selected Loss of GCU power When connection is lost, no DLA Test GCU power (red/B+) Speed not (B+ or Ground). movement will be seen. When wire for supply voltage and Maintained (Potentially connection is restored, GCU will...
  • Page 62 Governor System ORIGINAL DESIGN Electronic Governor Troubleshooting Flow Chart Turn off key switch. Do Not Touch Digital Linear Actuator (DLA) NOTE: DLA is not a solenoid. It is a precision electronic motor. Do not exert force to center clevis shaft! Visually inspect DLA and Linkage.
  • Page 63 Engine speed increases Operation Input Voltage: (if it was at low speed). 0-1 Volts at Idle/9+ Volts at High Speed. Kohler electronic governor system tests OK. Test Fail Pass control system of equipment. Refer to Equipment Manufacturer’s diagnostic procedures for control system.
  • Page 64 Governor System ORIGINAL DESIGN Electronic Governor Troubleshooting Flow Chart Continued Turn key switch to ON position. Test supply voltage to GCU using volt meter. Refer to page 58 (battery voltage +/- 1 volt) Note: Prevent Damage to Connector. Do Not Use Oversized Probe Tips. Proceed to DLA Circuit Test.
  • Page 65 Governor System FIELD INSTALLED UPDATED DESIGN GCU/Harness Diagnostics and Troubleshooting This updated design was fi rst released as a fi eld installed kit with a sealed GCU/wiring harness module assembly and separate red wire w/yellow tracer speed control input. Ground and Power Test NOTE: This updated design features a sealed GCU module wiring harness assembly that is serviced as an assembly and must NOT be separated.
  • Page 66 Governor System FIELD INSTALLED UPDATED DESIGN GCU Blink Speed control issues can also be diagnosed utilizing Code Tests on-board Blink Code diagnostic lights equipped in GCU. These GCUs store blink codes/trouble codes, that can be quickly diagnosed using blink code charts. Green LED Light Yellow LED Light FIELD INSTALLED UPDATED DESIGN GCU Blink Codes for Software Stored Codes - Activated when key...
  • Page 67 Governor System FIELD INSTALLED UPDATED DESIGN GCU Blink Codes for Software Running Codes - Activated when engine is running. Response LED Diagnostics Failure Condition Possible Causes Response Time Yellow LED Green LED Running Normally None BLINKS BLINKS RPM Too High Mechanical bindage None BLINKS...
  • Page 68 Governor System FIELD INSTALLED UPDATED DESIGN Troubleshooting Electronic Governor Failure Condition Possible Causes Equipment Observations Inspection/Testing Target/Selected Loss of GCU power When connection is lost, no DLA Test GCU power (red/B+) Speed not (B+ or Ground). movement will be seen. When wire for supply voltage and Maintained (Potentially...
  • Page 69 Governor System FIELD INSTALLED UPDATED DESIGN Electronic Governor Troubleshooting Flow Chart Turn off key switch. Do Not Touch Digital Linear Actuator (DLA) NOTE: DLA is not a solenoid. It is a precision electronic motor. Do not exert force to center clevis shaft! Visually inspect DLA and Linkage.
  • Page 70 Operation Input Voltage: Engine speed increases 0-1 Volts at Idle/9+ Volts at High Speed. (if it was at low speed). Kohler electronic governor system tests OK. Test Fail Pass control system of equipment. Refer to Equipment Manufacturer’s diagnostic procedures for control system.
  • Page 71 Governor System FIELD INSTALLED UPDATED DESIGN Electronic Governor Troubleshooting Flow Chart Continued Turn key switch to ON position. Test supply voltage to GCU using volt meter. Refer to page 65. (Battery voltage +/- 1 volt) DLA function can be tested and confi rmed using a stepper motor controller tool. Refer to Tools and Aids. Testing instructions are included with tool.
  • Page 72 Governor System 6. With tool installed, start engine. Connect a jumper NEW UPDATED DESIGN GCU/Harness Diagnostics wire (technician supplied) to red w/yellow tracer and Troubleshooting bullet of tool. Connect other end of jumper wire to A new updated design has been released with a sealed battery 12 volt +.
  • Page 73 Governor System NEW UPDATED DESIGN GCU Blink Code Tests Speed control issues can also be diagnosed utilizing on-board Blink Code diagnostic lights equipped in GCU. These GCUs store blink codes/trouble codes, that can be quickly diagnosed using blink code charts. Green LED Light Yellow LED Light NEW UPDATED DESIGN GCU Blink Codes for Software Stored Codes - Activated when key is turned to ON...
  • Page 74 Governor System NEW UPDATED DESIGN GCU Blink Codes for Software Running Codes - Activated when engine is running. Response LED Diagnostics Failure Condition Possible Causes Response Time Yellow LED Green LED Running Normally None BLINKS BLINKS RPM Too High Mechanical bindage None BLINKS RPM Too Low...
  • Page 75 Governor System NEW INSTALLED UPDATED DESIGN Troubleshooting Electronic Governor Failure Condition Possible Causes Equipment Observations Inspection/Testing Target/Selected Loss of GCU power When connection is lost, no DLA Test GCU power (red/B+) Speed not (B+ or Ground). movement will be seen. When wire for supply voltage and Maintained (Potentially...
  • Page 76 Governor System NEW UPDATED DESIGN Electronic Governor Troubleshooting Flow Chart Turn off key switch. Do Not Touch Digital Linear Actuator (DLA) NOTE: DLA is not a solenoid. It is a precision electronic motor. Do not exert force to center clevis shaft! Visually inspect DLA and Linkage.
  • Page 77 Operation Input Voltage: Engine speed increases 0-1 Volts at Idle/9+ Volts at High Speed. (if it was at low speed). Kohler electronic governor system tests OK. Test Fail Pass control system of equipment. Refer to Equipment Manufacturer’s diagnostic procedures for control system.
  • Page 78 Governor System Basic Electrical Diagram of Electronic Governor System ECU Speed Output (speed signal) Power Speed Signal Green LED Light Device Yellow LED Light Ground DLA Driver Controls Application Supplied Speed Control Input Operation Input Voltage: 0-1 Volts at Idle/9+ Volts at High Speed KohlerEngines.com 62 690 05 Rev.
  • Page 79 Governor System MECHANICAL GOVERNOR Governed speed setting is determined by position of throttle control. It can be variable or constant, depending on engine application. Governor is designed to hold engine speed constant under changing load conditions. Governor gear/fl yweight mechanism is mounted inside crankcase and is driven off gear on camshaft. Components Inside Engine Throttle Lever...

  • Page 80: Lubrication System

    Lubrication System This engine uses a full pressure lubrication system which delivers oil under pressure to crankshaft, camshaft, connecting rod bearing surfaces, and hydraulic valve lifters. A high-effi ciency gerotor oil pump maintains high oil fl ow and oil pressure, even at low speeds and high operating temperatures.
  • Page 81 Lubrication System OIL COOLER Installation NOTE: Oil cooler is mounted under cylinder shroud. 1. Apply pipe sealant with Tefl on (Loctite 592™ ® ® ® Removal of cylinder shroud is necessary to Thread Sealant or equivalent) to threads of switch. access oil cooler.

  • Page 82: Electrical System

    Electrical System BATTERY CHARGING SYSTEM ● Disconnect rectifi er-regulator plug and/or wiring harness plug before doing any electric welding on equipment powered by engine. Also, disconnect all CAUTION other electrical accessories in common ground with Electrical Shock can cause injury. engine.
  • Page 83 Electrical System FUSES b. Run engine at high speed no load (greater than 3000 RPM). After running 1 minute, measure This engine has 3 blade type automotive fuses. voltage at battery. Replacement fuses must have same rating as blown fuse. Use fuse chart below to determine correct fuse. i.
  • Page 84 Electrical System IGNITION SYSTEM Inspection Spark Plug Inspect each spark plug as it is removed from cylinder Spark Plug Component and Details head. Deposits on tip are an indication of general condition of piston rings, valves, and fuel mixture. Normal and fouled plugs are shown in following photos: Normal Plug taken from an engine operating under normal conditions will have light tan or gray colored deposits.
  • Page 85 Isolate and verify trouble is within engine. 1. If Kohler diagnostic software is available, review "Safety System Active" status in Data Display screen. If yes is displayed, equipment safety circuit is active (seat switch/PTO switch/Safety interlocks, etc.). This must be corrected prior to continuing testing.
  • Page 86 Electrical System Test for Spark NOTE: If 2 ignition system testers are available, testing can be performed simultaneously for both cylinders. However, if only 1 tester is available, 2 individual tests must be performed. Side not being tested must have spark plug lead connected or grounded.

  • Page 87: Starter System

    Starter System NOTE: Do not crank engine continuously for more than 10 seconds. Allow a 60 second cool down period between starting attempts. Failure to follow these guidelines can burn out starter motor. NOTE: If starter is engaged while fl ywheel is rotating, starter pinion and fl ywheel ring gear may clash and damage starter.
  • Page 88 Starter System SOLENOID SHIFT STARTERS Starter Disassembly When power is applied to starter electric solenoid moves NOTE: Do not reuse old retainer. drive pinion out onto drive shaft and into mesh with NOTE: Do not soak armature or use solvent when fl...
  • Page 89 4 brushes and springs are serviced as a set. Use a new holes in metal clips must be up/out. Slide brush Kohler brush and spring kit if replacement is necessary. holder assembly down into place around 1. Perform steps 1-5 in Starter Disassembly.
  • Page 90 Starter System c. Install brush springs and snap on retainer caps. d. Hold starter assembly vertically on end housing, and carefully place tool (with extension) and assembled original brush holder assembly onto end of armature shaft. Slide brush holder assembly down into place around commutator, install positive (+) brush lead grommet in cutout of frame.
  • Page 91 Disassembly/Inspection and Service WARNING Before working on engine or equipment, disable engine as Accidental Starts can cause severe injury or follows: 1) Disconnect spark plug lead(s). 2) Disconnect death. negative (–) battery cable from battery. Disconnect and ground spark plug lead(s) before servicing.
  • Page 92 Disassembly/Inspection and Service Clean all parts thoroughly as engine is disassembled. Remove Fuel Pump Module/Fuel Pump Assembly Only clean parts can be accurately inspected and gauged for wear or damage. There are many WARNING commercially available cleaners that will quickly remove grease, oil and grime from engine parts.
  • Page 93 Disassembly/Inspection and Service 3. Remove screws and #2 side valley baffl e. Remove #2 Barrel and Valley Baffl es 4. If necessary, carefully depress clip & remove coil 1. Disconnect wiring harness lead from coil (#2 oil from barrel baffl e. cooler side).
  • Page 94 fl ywheel, crankshaft, and key if fl ywheel key is sheared or keyway is damaged. Inspect ring gear for cracks or damage. Kohler does not provide ring gear as a serviceable part. Replace fl ywheel if ring gear is damaged.
  • Page 95 Disassembly/Inspection and Service NOTE: Further disassembly of oil fi lter housing Remove Oil Filter Housing assembly is not required unless being serviced Oil Filter Housing Components individually. Follow substeps a, b, and c. 1. Remove screw securing oil fi lter housing and individual O-rings to crankcase.
  • Page 96 Disassembly/Inspection and Service Cylinder Head Components Style B Style A Gasket Valve Cylinder Head Pipe Plug Guide Plate Spacer Washer Spark Plug Valve Stem Seal Valve Spring Valve Spring Retainer Hydraulic Lifter Valve Spring Keeper Push Rod Rocker Arm Rocker Arm Pivots Rocker Stud Valve Cover Seal Valve Cover...
  • Page 97 If lifters need to be replaced, apply a liberal 2. Remove valve cover and seal from each cylinder coating of Kohler lubricant to base of each new lifter head. Note locations of individual valve covers if before it is installed.
  • Page 98 Disassembly/Inspection and Service Inspection and Service Valve Details EXHAUST VALVE INTAKE VALVE Dimension Intake Exhaust Seat Angle 44.5° 44.5° Seat Taper 30° 30° Guide Depth 8.5 mm (0.334 in.) 8.5 mm (0.334 in.) Guide I.D. 7.038/7.058 mm (0.2771/0.2779 in.) 7.038/7.058 mm (0.2771/0.2779 in.) Valve Head Diameter 38.625/38.685 mm (1.5206/1.5230 in.) 31.625/31.825 mm (1.2450/1.2549 in.)
  • Page 99 Disassembly/Inspection and Service Recondition valve seat inserts following instructions of grinding compound, then rotate valve on its seat with provided with valve seat cutter being used. Final cut grinder. Continue grinding until a smooth surface is should be made with an 44.5° cutter as specifi ed for obtained on seat and on valve face.
  • Page 100 Disassembly/Inspection and Service Reassembly Remove Breather Assembly Torque Sequence 1. Carefully remove harness clip from #1 valley baffl e (if not already removed). 2. Remove fasteners securing breather assembly and gasket to crankcase. 3. Carefully break gasket seal and remove breather and fi...
  • Page 101 Disassembly/Inspection and Service Crankcase Components Camshaft Locking Tab* Regulating Pin* Governor Gear* Lifter Feed Cross Shaft* Lifter Feed Cover Governor Yoke* Gasket Cover Connecting Rod Crankshaft Connecting Rod Piston Pin End Cap Piston Pin Retainer Piston Piston Ring Set Oil Seal *Mechanical Governor only.
  • Page 102 Disassembly/Inspection and Service Scuffi ng and scoring of pistons and cylinder walls occurs Remove Camshaft when internal engine temperatures approach welding Remove camshaft and shim (if used). point of piston. Temperatures high enough to do this are created by friction, which is usually attributed to improper Inspection lubrication and/or overheating of engine.
  • Page 103 Disassembly/Inspection and Service 5. After installing new compression (top and middle) Inspection and Service rings on piston, make sure ring-to-groove side Crankshaft Components and Details clearance is 0.04/0.08 mm (0.0015/0.0031 in.). If side clearance is greater than specifi ed, a new piston must be used.
  • Page 104 Governor gear is located within crankcase. Inspect governor gear teeth. Replace gear if it is worn, chipped, NOTE: Kohler pistons are custom-machined to exacting or if any teeth are missing. Inspect governor weights. tolerances. When oversizing a cylinder, it should They should move freely in governor gear.
  • Page 105 Disassembly/Inspection and Service 1. Lower hone into bore and after centering, adjust so Measuring Piston-to-Bore Clearance stones are in contact with cylinder wall. Use of a Piston Detail commercial cutting-cooling agent is recommended. 2. With lower edge of each stone positioned even with lowest edge of bore, start drill and honing process.
  • Page 106 Disassembly/Inspection and Service ORIGINAL DESIGN Electronic Governor Intake and Throttle Body Assembly Components Elbow Elbow O-ring Throttle Body Intake Manifold Fuel Rail Assembly Breather Hose Injector MAP Sensor Air Cleaner Bracket Intake Air Lifting Bracket Assembly Temperature Sensor Throttle Body Lever Linkage &...
  • Page 107 Disassembly/Inspection and Service FIELD INSTALLED UPDATED DESIGN Electronic Governor Intake and Throttle Body Assembly Components Elbow Elbow O-ring Throttle Body Intake Manifold Fuel Rail Assembly Breather Hose Injector TMAP Sensor Air Cleaner Bracket Throttle Body Lever Lifting Bracket Assembly Adapter Sealed (Bonded) GCU Module Linkage &...
  • Page 108 Disassembly/Inspection and Service Remove Sealed (Bonded) GCU Module Wiring Harness Assembly (FIELD INSTALLED UPDATED DESIGN Electronic Governor) 1. Remove screws securing sealed (bonded) GCU module wiring harness assembly to GCU bracket. 2. Disconnect DLA wire. 3. Cut nylon tie straps retaining GCU wiring harness to GCU wire tie-down bracket. 4.
  • Page 109 Disassembly/Inspection and Service Remove Throttle Body (NEW UPDATED DESIGN Electronic Governor) 1. Disconnect TPS wire. 2. Loosen 2 screws securing lifting bracket and air cleaner bracket to intake manifold. 3. Remove nuts securing elbow and throttle body. 4. Cut nylon tie strap retaining GCU wiring harness to GCU wire tie-down bracket. 5.
  • Page 110 Disassembly/Inspection and Service Mechanical Governor Intake and Throttle Body Assembly Components Elbow Elbow O-ring Throttle Body Intake Manifold Fuel Rail Assembly Breather Hose Injector MAP Sensor Air Cleaner Bracket Intake Air Speed Control Assembly Temperature Sensor Bracket Throttle Linkage Linkage Spring TMAP Sensor Remove Throttle Body (Mechanical Governor) 1.
  • Page 111 Disassembly/Inspection and Service Remove ECU Fuel Pump Module/Pump Assembly Components 1. Remove screws securing ECU to bracket. 2. Disconnect black and grey electrical connectors from ECU. 3. Reverse procedure to install. Torque screws to 6.2 N·m (55 in. lb.). Remove Fuel Injectors 1.
  • Page 112 Reassembly Crankcase Components Camshaft Locking Tab* Regulating Pin* Governor Gear* Lifter Feed Cross Shaft* Lifter Feed Cover Governor Yoke* Gasket Cover Connecting Rod Crankshaft Connecting Rod Piston Pin End Cap Piston Pin Retainer Piston Piston Ring Set Oil Seal * Mechanical Governor only. KohlerEngines.com 62 690 05 Rev.
  • Page 113 Reassembly NOTE: Make sure engine is assembled using all Install Governor Shafts, Seal, and Governor Gear specifi ed torque values, torque sequences, and (Mechanical Governor only) clearances. Failure to observe specifi cations Governor Components and Details could cause severe engine wear or damage. Always use new gaskets.
  • Page 114 Reassembly Install Crankshaft Install Camshaft Carefully slide fl ywheel end of crankshaft through oil seal 1. Liberally apply camshaft lubricant to each cam lobe. in crankcase. Lubricate camshaft bearing surfaces of crankcase and camshaft with engine oil. Install Connecting Rods with Pistons and Rings 2.
  • Page 115 Reassembly Breather/Oil Pan Components Oil Pan Gerotor Gears Oil Pump O-Ring Oil Pump Housing Pickup Tube Inlet Seal Pickup Screen Drain Plug Crankshaft Thrust Bearing Oil Pan Gasket Breather Filter Breather Gasket (Flange PTO) Crankshaft Non- Breather Assembly Oil Seal Thrust Bearing Check Ball Kit (PTO)
  • Page 116 Reassembly PTO Oil Seal Install Oil Pan Assembly Details Torque Sequence 3.0 mm (0.118 in.) Oil Seal 1. Check to make sure there are no nicks or burrs in crankshaft seal bore of oil pan. 2. Lightly oil outside diameter of oil seal. 3.
  • Page 117 Reassembly Cylinder Head Components Style B Style A Gasket Valve Cylinder Head Pipe Plug Guide Plate Spacer Washer Spark Plug Valve Stem Seal Valve Spring Valve Spring Retainer Hydraulic Lifter Valve Spring Keeper Push Rod Rocker Arm Rocker Arm Pivots Rocker Stud Valve Cover Seal Valve Cover...
  • Page 118 Reassembly Install Hydraulic Lifters Install Cylinder Heads NOTE: Hydraulic lifters should always be installed in Torque Sequence same position as they were disassembled. Exhaust lifters are located on output shaft side of engine while intake lifters are located on fan side of engine.
  • Page 119 Reassembly b. Insert a 0.406/0.483 mm (0.016/0.019 in.) feeler Install Guide Plate, Pivot Studs, Push Rods and gauge between end of one valve and rocker arm. Rocker Arms Turn adjuster until a slight drag is felt. Hold NOTE: Install push rod guide plate so fl ange is down adjuster in this position and tighten locking (towards cylinder) on side 1, and up (away from setscrew.
  • Page 120 Reassembly Oil Cooler/Filter Components Oil Filter Oil Filter Nipple Valve Spring Cup Spring Oil Filter Valve Screw Oil Filter Housing O-Ring Install Oil Filter Housing Assembly Reassemble oil fi lter housing if disassembled previously. Reassembly 1. Install small spring onto rubber valve, and insert small end through corresponding hole in cup until properly seated.
  • Page 121 Reassembly Backing Shroud/Intake Manifold/Throttle Body/Air Cleaner/Flywheel/Fan Assembly Components Special Washer Debris Screen Stiff ener Flywheel Screw (Style A) (Style A) (Style A) Flywheel/Fan/Hex Backing Shroud/ Crankshaft Position Washer Stud Assembly Intake Manifold/ Sensor (Style A) Air Cleaner Rectifi er-Regulator MAP or TMAP Stator Ground Lead Connector...
  • Page 122 Reassembly Install Intake Manifold/Throttle Body//Air Cleaner/ Install Ground Lead and Rectifi er-Regulator Backing Shroud Assembly Connector Intake Manifold Torque Sequence 1. Attach ground lead to outer rectifi er-regulator mounting screw and washer, then torque mounting screw to 2.5 N·m (22 in. lb.). 2.
  • Page 123 Reassembly Install Crankshaft Position Sensor Install Metal Debris Screen (Style B) NOTE: Ensure all parts are clean, undamaged, and free Spring Washer Details of debris; make sure electrical connectors have seal in place. NOTE: On engines with earlier design bracket, an air gap must be set when installing.
  • Page 124 Reassembly External Engine Components Dipstick Oil Drain Plug Oil Fill Tube Valley Baffl e Spark Plug Lead Barrel Baffl e Starter Assembly Ignition Coil Fuel Pump Module Fuel Filter Fuel Pump Module Fuel Pump Baffl e High Pressure Fuel Electrical Connector Evap Line Oil Cooler Line Connector...
  • Page 125 Reassembly Install Valley and Cylinder Barrel Baffl es Install Electric Starter 1. Install #1 side valley baffl e and secure with 3 1. Install electric starter motor using screws. screws. Reinstall clip securing harness to baffl e. 2. Torque screws to 16 N·m (142 in. lb.). Install #2 side valley baffl...
  • Page 126 Reassembly Mechanical Governor Control Bracket Components Throttle Lever Control Bracket Throttle Linkage Linkage Spring Cross Shaft Governor Lever Governor Spring Idle Spring Install Governor Lever (Mechanical Governor Only) Install Muffl er Install governor lever onto governor shaft and connect Oxygen Sensor Wire Detail throttle linkage with black clip.
  • Page 127 Reassembly 4. Install oxygen sensor, torque to 50.1 N·m (37 ft. lb.) Testing Engine and connect to wire harness. It is recommended engine be operated on a test stand or 5. Install spark arrestor (if used). bench prior to installation in equipment. 1.
  • Page 128 1P62 690 05 85612 22194 © 2018 by Kohler Co. All rights reserved. KohlerEngines.com 62 690 05 Rev. E...

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