TRANSFORMER GP-IGNITION 2326353 - Caterpillar

Illustration 1 g01363134
Connections of the backup alarm relayThis diagnostic code is associated with the backup alarm relay. The FMI 6 means that the ECM has determined that there is a short to ground in the relay circuit. The possible causes of this diagnostic code are listed:
The energize circuit of the relay is shorted to ground.
The relay has failed.
The ECM has failed. This is unlikely. Note: The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear these diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of SPN 1619 FMI 6 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE RELAY.
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
Observe the status of the diagnostic code.
Disconnect the relay with the active diagnostic code from the machine harness. Expected Result:The FMI 6 changes to FMI 5 when the relay is disconnected.Results:
YES - The FMI 6 changes to FMI 5 when the relay is disconnected. The circuit is correct.Repair: The relay has failed. Replace the relay. Verify that the new relay corrects the problem.STOP
NO - The diagnostic code remains active. Proceed to Test Step 2.Test Step 2. CHECK THE ENERGIZE CIRCUIT OF THE RELAY FOR A SHORT TO GROUND.
Turn the key start switch and the disconnect switch to the OFF position.
The relay remains disconnected from the machine harness.
Disconnect the machine harness connector(s) from the ECM.
At the machine harness connector, measure the resistance from the signal contact J2-55 to all other contacts that are used in the machine harness connectors for the ECM. Expected Result:Each resistance measurement is greater than 5000 ohms.Results:
OK - Each resistance measurement is greater than 5000 ohms. The machine harness is correct. Proceed to Test Step 3.
NOT OK - Each resistance measurement is not greater than 5000 ohms. There is a short in the machine harness. The short is between J2-55 and the circuit with the low resistance measurement.Repair: Repair the machine harness or replace the machine harness. STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
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 harness connectors. Make sure that the harness 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 vehicle.
Check the status of the diagnostic code.Expected Result:The diagnostic code is active.Results:
YES - The diagnostic code is active. The diagnostic code has not been corrected.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. Prior to replacing an ECM, always contact your dealership for possible consultation with Caterpillar. This consultation may