TroubleshootNg Chart - Mec 34-J Diesel Service & Parts Manual

Secton 19 - Troubleshootng
The following chart describes the possible causes for inoperation of the different functions of this
machine. The Causes and Solutions columns list various points of references that can be found in the
Hydraulic, Electrical, Schematics and Troubleshooting sections of this manual.
The majority of electrical troubleshooting on this model will require the use of the onboard EZ-Cal
scan tool, located inside the lower control box door. Please refer to "EZ-Cal Scan Tools" on page 98
for further instructions on the use of the EZ-Cal scan tool.
Perform a full assessment of machine operations prior to troubleshooting this model and using this
chart. This model is operated by a Microprocessor Control System equipped with a variety of built-
in safety interlocks to prevent continued operation in the event of a failure or misoperation. Some
interlocks may only be detected through the use of the EZ-Cal.
Problem
General Power Issue
Emergency stop switch pushed in
or ignition switch turned off or faulty
switches
Battery discharged or faulty cables
No operation from upper
or lower control station.
Circuit breaker tripped
No LEDs on modules.
Faulty Terminal Block Module
(TBM)
Flash codes are the GP500's
No operation from upper
indication of a fault in the system.
or lower control station
Module LEDs on or
flashing
Starter Relay or Starter failure
Base/Platform select switch not
in Platform position or switch
malfunction
Operates from lower
Damaged or loose harness
controls but not from
connections to upper control box
upper controls. No LEDs
when in Upper control
Malfunctioning GP440 Module
position.
(Module inside the upper control
box)
System interlock
Problem
Engine Related Issues
Battery discharged or faulty cables
Malfunctioning start relay or fuse
Starter will not crank from
upper or lower stations Malfunctioning starter
Faulty start switch either location
Starter interrupt system initiated
Page 109
Troubleshooting Chart
Possible Cause
Lower E-stop switch and ignition switch will cut all power.
Upper E-stop will cut only upper power as will the ignition switch in
platform control box.
Will receive 4-4 or 7-7 flash on GP500. Clean, service and charge battery.
Repair cables.
Located in lower control box. Look for short circuit and/or damage in wiring
or high amperage draw at valve coils or engine actuators.
Located inside the lower control box. Initiates all power when signaled by
the key switch. Check for loose terminals.
Terminal 4 is Common power from Circuit breaker.
Terminals 1 and 2 are signals to close the relay.
Refer to flash code designation in this section of the manual or plug in an
EZ-Cal scan for more relevant information relating to the failure. See EZ-
Cal Instructions for more information.
Test for signal and Common power to Starter Relay. Check fuse for
Common power to relay. Test Starter.
Ensure that the switch is in the Platform position. Check switch function.
Check for power inside the upper control box on E-stop switch and at
Buss Module. Check for presence of ground on the Ground Buss Module.
Repair connections.
Check help messages using the EZ-Cal tool. Also check for joystick inputs
(see 2C2 and 2D2 Diagnostic Chart for inputs from GP440).
Check EZ-Cal HELP messages for interlock
Possible Cause
Will receive 4-4 flash on GP500. Clean, service and charge battery. Repair
cables.
Test/replace relay located on left hand side of engine and fuse located
near starter
Test/replace starter
Test/replace as necessary
Check for red "Start Disable" light on lower panel. Starter may be operated
for 10 seconds before a 30 second "cool down" is initiated.
34-J Desel - Servce & Parts Manual
December 2021
Remedy/Solution
Remedy/Solution