This diagnostic code is recorded when the system voltage is greater than 20 VDC. The FMI 03 means that the ECM determined that the voltage is above normal.
Test Step 1. CHECK FOR DIAGNOSTIC CODE
- Turn the key start switch to the OFF position.
- Occupy the seat.
- Place the armrest in the DOWN position.
- Start the engine.
- Run the engine at high idle for several minutes.
- Check the Caterpillar ET for the active diagnostic code of CID 0168 FMI 03.
Expected Result:
The diagnostic code of CID 0168 FMI 03 should not be active.
Results:
- OK - The diagnostic code of CID 0168 FMI 03 is not active.
Repair: There is no problem at this time.
Stop.
- NOT OK - The diagnostic code of CID 0168 FMI 03 is active. Proceed to Test Step 2.
Test Step 2. CHECK THE SYSTEM VOLTAGE
Note: The following steps are performed with the engine at high idle.
- Check the system voltage that is displayed on the Caterpillar ET.
- Measure the voltage at the battery posts.
Expected Result:
The voltage readings should be less than 20 VDC.
Results:
- OK - The voltage readings are less than 20 VDC.
Repair: The ECM is very unlikely to have failed. Reconnect all connections and visually inspect the wire harness. Verify that the values that are present on the machine configuration screen match the machine's options. Verify that the values that are present on the machine configuration screen are installed correctly. Verify that the diagnostic code still exists. If the diagnostic code still exists perform the test steps again.Replace the ECM, if the cause of the diagnostic code was not found after the second attempt. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
Stop.
- NOT OK - The voltage readings are greater than 20 VDC.
Repair: The charging system is charging at an excessive voltage. Check the charging system. See Service Manual, REHS0354, "Starting System Troubleshooting".
Stop.
- NOT OK - Voltage readings above 20 VDC are displayed on the ET. Proceed to Test Step 3.
Test Step 3. CHECK THE VOLTAGE AT THE ECM
- Turn the key start switch to the OFF position.
- Remove the floorplate in order to get to the auxiliary hydraulic ECM.
- Disconnect the wire harness from the ECM.
- Start the engine and run the engine at high idle.
- Measure the voltage from contact 1 to contact 3 of the wire harness connector.
Expected Result:
The voltage should be less than 20 VDC.
Results:
- OK - The voltage is less than 20 VDC.
Repair: The ECM is very unlikely to have failed. Reconnect all connections and visually inspect the wire harness. Verify that the values that are present on the machine configuration screen match the machine's options. Verify that the values that are present on the machine configuration screen are installed correctly. Verify that the diagnostic code still exists. If the diagnostic code still exists perform the test steps again.Replace the ECM, if the cause of the diagnostic code was not found after the second attempt. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
Stop.
- NOT OK - The voltage is greater than 20 VDC.
Repair: The charging system is charging at an excessive voltage. Check the charging system. See Service Manual, REHS0354, "Starting System Troubleshooting".
Stop.