BUSHING 2B9245 7B4389 - Caterpillar

Illustration 1 g01319031
Connections of the backup alarm relayThis diagnostic code is associated with the backup alarm relay. The FMI 03 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 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 CID 0637 FMI 03 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 ON position.
Disconnect the wires from the back of the connector at the ECM.
At the machine harness connector for the relay, measure the voltage from contact 1 (wire 121-RD) to frame ground. At the machine harness connector for the relay, measure the voltage from contact 3 (wire 321-BR) to frame ground.Expected Result:The voltage is 0 VDC.Results:
OK - There are no shorts in the wires. Proceed to Test Step 2.
NOT OK - A voltage is present in the wires. There is a short in the machine harness or in the wires. The short is to a separate voltage source.Repair: Repair the machine harness or replace the machine harness. Ensure that the fix has corrected the problem.STOPTest Step 2. CHECK THE OPERATION OF THE ECM.The disconnect switch and the key start switch remain in the OFF position. The machine harness connectors for the relay and the ECM remain disconnected.
Use a removal tool in order to remove the wire that energizes the relay from the harness. Remove wire (321-BR) from contact J2-5.
Reconnect the machine harness connectors to the ECM.
Turn the disconnect switch and the key start switch to the ON position.
Observe the status of the active diagnostic code.Expected Result:The diagnostic code of a FMI 03 changes to a FMI 05.Results:
OK - The FMI 03 changes to a FMI 05. The FMI 05 was activated after the energize circuit for the relay was disconnected. The ECM has responded correctly to the condition of an open circuit in the relay circuit. Reconnect the disconnected wire. Wire (321-BR) connects to the ECM at connector contact J2-5. Proceed to Test Step 3.
NOT OK - The FMI 03 does not change to a FMI 05. The diagnostic code did not change after the wire for the relay was disconnected.Repair: The ECM has not responded correctly to the condition of an open circuit in the relay circuit. The operation of the ECM is not correct. Replace the ECM. Prior to replacing an ECM, always contact your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace".STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE IS STILL ACTIVE.
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