ROD 8P3328 - Caterpillar

Illustration 1 g01363134
Connections of the backup alarm relayThis diagnostic code is associated with the backup alarm relay. The FMI 3 means that the ECM has determined that the voltage of the relay circuit is above normal.The possible causes of the diagnostic code are listed:
The relay has failed.
The energize circuit of the relay is shorted to the +battery circuit.
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 3 is active before performing this procedure.Note: Use a digital multimeter for the measurements in this procedure.Test Step 1. CHECK THE ENERGIZE CIRCUIT OF THE RELAY FOR A SHORT TO THE +BATTERY CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors from the relay and the ECM.
At the machine harness connector for the ECM, measure the resistance from contact J2-55 to all 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 2.
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 that has a low resistance measurement.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 harness connectors in order to make sure that the connectors are fully seated. Also, make sure 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 diagnostic code is active.Expected Result:The diagnostic code is active.Results:
YES - The diagnostic code is active. The diagnostic code has not been corrected.Repair: Check the circuit again. 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 greatly reduce repair time. If the ECM requires replacing, refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOP
NO - The diagnostic code is not active. The diagnostic code does not exist at this time. 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.STOP