BRACKET 9D0972 - Caterpillar

Illustration 1 g03809979
Schematic of Back Up Alarm Relay
This diagnostic code is associated with the Back Up Alarm Relay. The backup alarm relay is controlled by the ECM through an ON/OFF output driver. The FMI 03 diagnostic code means the ECM has determined that voltage is present in the relay circuit when the output driver is OFF.The conditions that could cause this diagnostic code to activate are listed:
The relay has failed.
The energize circuit of the relay is shorted to another voltage source.
The ECM has failed. The failure of the ECM is unlikely.Note: Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all connections in the circuit meet the following requirements: clean, secure and good condition. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure. Note: The following test procedure may cause other diagnostic codes to be activated. Ignore these created diagnostic codes and clear the diagnostic codes when the problem has been corrected.Note: Use a calibrated digital multimeter for the measurements in this procedure.System Response:The backup alarm is on.Test Step 1. Check The Relay
Turn the key start switch and the disconnect switch to the ON position.
While the status of the active CID 144 FMI 03 diagnostic code is being observed, disconnect the backup alarm relay from the machine harness.
At the relay, measure the resistance of the coil between contact 85 and contact 86. Measure the resistance between power contact 30 and all of the other relay contacts. Expected Result:When the relay is disconnected from the harness, the status of the active CID 144 FMI 03 diagnostic code does not change.The resistance of the relay coil is in the range of 288 to 396 ohms at 25 °C (77 °F).The resistance measurement between power contact 30 and contact 87a is less than 5 ohms. The resistance measurement between the power contact 30 and all the other relay contacts is greater than 5000 ohms.Results:
OK - All of the checks for the relay are correct. The relay is not causing the problem. The CID 144 FMI 03 diagnostic code is still active. Proceed to Test Step 2.
NOT OK - The active CID 144 FMI 03 diagnostic code became inactive when the relay was disconnected. The resistance measurements are not correct with respect to the above specifications. The relay has failed.Repair: Verify that the relay has failed by substituting a known good relay that is the same part number for the suspect relay. Replace the suspect relay.STOPTest Step 2. Check The Energize Circuit Of The Relay For A Short The relay remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connectors J1 from the ECM for the machine.
At the machine harness connector J1 for the ECM, measure the resistance from contact J1-23 (wire 331-OR(Orange)) to all of