Section 6. Messages and Codes
Model 4700 Maintenance Manual
Fault Codes Refer to the “Pinout Matrix” located in Theory of Operation section for all voltage and resistance values and component interconnection. Code
Description
Notes/Corrective Action
76
Code 76: Slave TPA Detected CAN-Bus Error The Slave TPA has not received a communication message from the VM, HCB, or PPA.
Check voltage to TPA. Check communication wires between all modules for continuity and shorts to frame. If OK, replace the TPA.
77
Code 77: Slave TPA CAN-Bus Node Offline Too much time between communication from the VM and PPA to the TPA has elapsed. This code can also be caused by an open in a cable from the amplifier to the traction motors.
Verify battery voltage. If wrong voltage, set correct voltage via FlashWare (and re-Learn pots) or install correct voltage battery. Check power cable connections to the TPA and motors for continuity and correct torque. Check both traction motor encoders, temperature sensors, and connections. Check communication wires between VM, TPA, and PPA for continuity and shorts to frame. If OK, replace the TPA.
79
Code 79: Traction Contactor Driver Shorted The TPA did not see a voltage drop when the contactor was commanded closed.
Check the CT3 contactor for physical binding and welded tips. Measure voltage and resistance across coil. If OK, replace the TPA.
7A
Code 7A: Master KO Failure of Master Unit.
Check voltage to the TPA. If OK, replace the TPA.
7C
Code 7C: Slave TPA Internal Fault Slave TPA internal fault.
Check voltage to the TPA. If OK, replace the TPA.
80
Code 80: Traction Contactor Coil Driver Error Failure of the contactor driver.
Measure voltage and resistance across coil.
81
Code 81: Directional Microswitch Closed VM detected directional microswitches (SW9 or SW10; SW4 or SW5 on dual pedal trucks) closed prior to power up. This code can also be caused by having travel enable switch (SW8) activated before seat switch (SW2) and/or optional battery gate switch (SW30) is activated.
If the directional switch is left in forward or reverse position when the operator leaves the seat, Code 81 is displayed after a brief time-out (approx. 30 seconds). If the code still appears after lever is returned to neutral, cycle the Key switch to clear. Test switches for correct operation. Check continuity of wires from switches to cards. Flash truck components with latest version of software and re-Learn pots. Replace the VM.
6-20
Publication 1160093, Issued: 20 May 2013
