This diagnostic code is recorded when the ECM reads the system voltage as being greater than 31.5 DCV for at least 2 seconds.
The possible causes of this diagnostic code are listed:
- A charging system component has failed.
- The wiring of the machine harness has failed.
- The ECM has failed. This is unlikely.
System Response:
When this diagnostic code is active, the control system will default to the "Auto Not Allowed" state.
Test Step 1. CHECK THE CHARGING SYSTEM.
- Turn the disconnect switch and the key start switch to the ON position.
- View the status of the diagnostic code.
Expected Result:
The diagnostic code is NO longer active.
Results:
- YES - The diagnostic code is NO longer active. Proceed to test step 2.
- NO - The diagnostic code remains active. Proceed to test step 3.
Test Step 2. CHECK THE CHARGING SYSTEM AGAIN.
- Start the engine.
- View the status of the diagnostic code.
Expected Result:
The diagnostic code is NO longer active.
Results:
- YES - The diagnostic code is NO longer active. Watch for a recurrence. Stop.
- NO - The diagnostic code is active. The charging system is charging at an excessive voltage.
Repair: Check the charging system. See Special Instruction, REHS0354, "Charging System Troubleshooting" for more information.
Stop.
Test Step 3. CHECK THE BATTERY VOLTAGE.
- The engine should not be running.
- At the battery, measure the voltage of the battery.
Expected Result:
The voltage should measure less than 32 DCV.
Results:
- YES - The voltage measures less than 32 DCV. The ECM must be recording this diagnostic code incorrectly. The ECM may have failed.
Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is NOT found, replace the ECM. See Troubleshooting, "Module - Replace".
Stop.
- NO - The voltage measurement is greater than 32 DCV. The charging system is charging at an excessive voltage.
Repair: Check the charging system.
Stop.