TRUNNION 1U4103 - Caterpillar

Conditions Which Generate This Code:
Illustration 1 g01944364
Connections of the key start switchThe ECU detects the following condition:The signal from the keyswitch was erratic because the keyswitch was cycled at least three times within the last second.Note: This code can be generated by rapidly cycling the keyswitch. Some control modules on the application may require this action in order to prompt flash codes. If this occurs, clear the logged diagnostic codes in order to prevent future confusion or an incorrect diagnosis.System Response:The ECU will log the diagnostic code and the warning light on the control panel will flash while this diagnostic code is active. The ECU will stop energizing the injector solenoids and the engine will shut down.Test Step 1. CHECK THE HARNESS.
Turn the key start switch to the OFF position.
Inspect the harness.
Check for the proper mating.
Check the exposed wires for nicks and abrasions.
Check for moisture, dirt, or corrosion.
Check the pin/socket for a proper fit.Expected Result:The harness appears to be correct.Results:
OK - The harness appears to be correct. Proceed to test step 2.
NOT OK - The harness appears to be damaged.Repair: Repair the machine harness or replace the machine harness.STOPTest Step 2. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE.
Inspect the harness connectors. Clean the contacts of the harness connectors and check the wires for damage to the insulation that is caused by excessive heat, battery acid, or chafing.
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit.
Reconnect all of the harness connectors. Make sure that the connectors are fully seated and that the clips for each connector are completely fastened.
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Determine if the CID 1834 FMI 02 is active.Expected Result:The CID 1834 FMI 02 is active.Results:
YES - The CID 1834 FMI 02 is active. The problem has not been corrected.Repair: Check the circuit again. It is unlikely that the ECU has failed. Exit this procedure and perform this procedure again. If the cause of the diagnostic code is not found, replace the ECU. Prior to replacing an ECU, always contact your dealership's Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. See Testing and Adjusting, KENR8292, "Electronic Control Unit - Replace".STOP
NO - The CID 1834 FMI 02 is not active. The problem does not exist at this time.Repair: The initial diagnostic code was probably caused by a poor electrical connection at one of the harness connectors that was disconnected and reconnected. Resume normal machine operation.STOP