BODY 2478981 - Caterpillar

Illustration 1 g02727628
Electrical system voltage connections
This diagnostic code is recorded when the ECM reads the electrical system voltage as being above normal.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. An ECM failure is unlikely.Test Step 1. CHECK THE STATUS OF THE DIAGNOSTIC CODE.
Start the engine.
Clear the diagnostic code.
Operate the machine.
View the status of the diagnostic code.Expected Result:The diagnostic code is not active.Results:
OK - The diagnostic code is not active. Watch for a recurrence.STOP
NOT OK - The diagnostic code is active. The charging system is charging at an excessive voltage.Repair: Check the charging system.STOPTest Step 2. CHECK THE CHARGING SYSTEM COMPONENTSReference: Refer to Troubleshooting, REHS0354 manual for detailed instructions on troubleshooting the charging system components.Expected Result:The charging system is operating normally.Results:
OK - The charging system is operating normally. Proceed to Test Step 3.
NOT OK - The charging system is not operating normally.Repair: Repair the charging system in accordance with Troubleshooting, REHS0354.STOPTest Step 3. CHECK THE INTEGRITY OF THE CONNECTORS THAT ARE IN THE CHARGING SYSTEM
Inspect the harness connectors. Clean the contacts of the harness connectors. Check the wires for damage to the insulation that is caused by excessive heat, corrosion, or chafing.
Perform a 45 N (10 lb) Pull Test on each of the wires that are associated with the circuit.
Reconnect all harness connectors. Make sure that the connectors are fully seated and make sure that the clips for each connector are fastened.
Use the Cat® Electronic Technician (Cat® ET) service tool to perform a Wiggle Test on the machine wiring harness. The Wiggle Test can detect intermittent shorts or opens in the machine wiring harness.
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Determine if the CID 168 FMI 3 diagnostic code is active.Expected Result:The CID 168 FMI 3 diagnostic code is active.Results:
YES - The CID 168 FMI 3 diagnostic code is active. The problem has not been corrected. Proceed to Test Step 4.
NO - The CID 0168 FMI 03 diagnostic code is not active. The problem does not exist at this time.Repair: The initial diagnostic code 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.STOPTest Step 4. CHECK THE CHARGING SYSTEM FOR A SHORT IN THE HARNESS.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors from the alternator and the ECM.
Measure the resistance between the terminal of the "R" wire and all the contacts of the harness that are used for the charging system.
Measure the resistance between the terminal of the "F" wire and all the contacts of the harness that are used for the charging system.Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The circuit is correct. The ECM may have failed.Repair: An ECM failure is unlikely. Exit this procedure and perform this procedure again.