This diagnostic code is recorded when the system voltage is above 32.5 VDC. The diagnostic code should be ACTIVE only if the engine is running.
The possible causes of this diagnostic code are listed below:
- A charging system component has failed.
- The ECM has failed. This is unlikely.
Test Step 1. CHECK THE BATTERY VOLTAGE.
- Start the engine and run the engine at high idle for several minutes.
- Measure the battery voltage at the battery posts.
Expected Result:
The battery voltage should be less than 32.5 VDC.
Results:
- OK - The battery voltage is less than 32.5 VDC. The battery voltage is correct. Proceed to test step 2.
- NOT OK - The battery voltage is greater than 32.5 VDC.
Repair: The charging system is not correct. Check the charging system. See Special Instruction, REHS 0354, "Charging System Troubleshooting".
Stop.
Test Step 2. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE.
- Stop the engine. Make sure that no battery charger is connected to the engine.
- Remove the connector from the ECM. Inspect the contacts and clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Turn the key start switch to the ON position.
- Enter service mode of the Caterpillar Monitoring System and clear all inactive diagnostic codes.
- Operate the machine.
- Determine if CID 0168 FMI 00 is present.
Expected Result:
CID 0168 FMI 00 is present.
Results:
- YES - CID 0168 FMI 00 is present.
Repair: The problem has not been corrected. It is unlikely that the ECM has failed. Perform the previous Step again. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
Stop.
- NO - CID 0168 FMI 00 is not present.
Repair: The diagnostic code is NOT present. The problem does not exist at this time. The initial problem was probably caused by a poor electrical connection or a short at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.
Stop.