826G Landfill Compactor, 825G Soil Compactor, 824G Wheel Dozer and 980G Wheel Loader Power Train Electronic Control System Caterpillar

This diagnostic code is recorded when the system voltage is greater than 32.5 DCV. The solenoids may be damaged if the voltage remains high for an extended period of time.

Possible causes of this diagnostic code are listed:

• The alternator or the voltage regulator failed.

• Jump starting the machine with a welder.

System Response:

The machine response is listed:

• Starting is disabled.

• The functions of the transmission are disabled until the voltage is above 32.5 V and the direction switch is placed in neutral.

Note: Ensure that the diagnostic code is active and that the diagnostic code indicator is active.

Test Step 1. Check the Charging System.

1. Turn the key start switch to the ON position.

2. Ensure that the diagnostic code is active and that the diagnostic code indicator is active. See Testing and Adjusting, "Using Caterpillar Monitoring System to Determine Diagnostic Codes".

Expected Result:

The diagnostic code indicator is active.

Results:

• YES - The diagnostic code indicator is active. Proceed to test step 3.

• NO - The diagnostic code indicator is not active. Proceed to test step 2.

Test Step 2. CHECK THE CHARGING SYSTEM.

1. Start the engine.

2. Ensure that the diagnostic code is active.

3. Observe the status of the diagnostic code indicator.

Expected Result:

The diagnostic code indicator is active.

Results:

• YES - The diagnostic code indicator is active. The charging system is charging at an excessive voltage.

  Repair: Check the charging system. Refer to Special Instruction, REHS0354, "Charging System Troubleshooting".

  STOP

• NO - The diagnostic code indicator is not active.

  Repair: There is no problem at this time. Watch for a recurrence of this diagnostic code.

  STOP

Test Step 3. CHECK THE BATTERY VOLTAGE.

1. The engine is stopped.

2. At the battery, measure the voltage.

Expected Result:

The voltage is less than 35.5 VDC.

Results:

• OK - The voltage is less than 35.0 VDC. The ECM must be incorrectly recording this problem.

  Repair: It is unlikely that the ECM has failed. Perform the previous Steps again. If the cause of the problem is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (Power Train) - Replace".

  STOP

• NOT OK - The voltage is greater than 35.5 VDC. The charging system is charging at an excessive voltage.

  Repair: Check the charging system. See Testing and Adjusting, "Starting and Charging System" .

  STOP