FITTING GP-EXHAUST 3843677 - Caterpillar

Illustration 1 g01124426
Schematic of the backup alarm
This diagnostic code is associated with the backup alarm. The FMI 05 means that the ECM has determined that the current of the alarm circuit is below normal. The possible causes of this diagnostic code are listed below:
The energize circuit of the alarm is open.
The return circuit of the alarm is open.
The alarm 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 CID 0637 FMI 05 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.Test Step 1. CHECK THE ALARM.
Turn the disconnect switch and the key start switch to the ON position. DO NOT start the engine.
Disconnect the machine harness from the alarm.
At the machine harness connector for the alarm, place a jumper wire from contact 1 (wire 327-BR(Brown)) to contact 2 (wire H807-YL(Yellow)).
Observe the status of the diagnostic code. Expected Result:The diagnostic code is active. Then, the diagnostic code is NOT active as the jumper wire is installed and removed.Results:
YES - The circuit is correct. The alarm has failed.Repair: Repeat this test "CHECK THE ALARM" in order to verify that the alarm has failed. Replace the alarm.STOP
NO - The diagnostic code remains active. Proceed to test step 2.Test Step 2. CHECK THE CIRCUIT for the ALARM FOR AN OPEN.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
Disconnect the J2 machine harness connector from the ECM.
At the machine harness connector for the alarm, the jumper wire remains installed.
At J2 and J1 machine harness connectors, measure the resistance from contact J2-4 (wire H807-YL(Yellow)) to J1-12 (wire 327-BR(Brown)). Expected Result:The resistance should be less than 5 ohms.Results:
YES - The resistance is less than 5 ohms. The machine harness is correct. Proceed to test step 3.
NO - The resistance measurement is NOT correct. There is an open circuit in the machine harness.Repair: The open is in the wire (327-BR(Brown)) for the signal of the alarm or in wire (H807-YL(Yellow)) of the machine harness. Repair the machine harness or replace the machine harness.STOPTest Step 3. CHECK IF THE DIAGNOSTIC CODE REMAINS.
Inspect the contacts and clean the contacts of the harness connectors.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Clear all inactive diagnostic codes.
Operate the machine.
Stop the machine and place the parking brake switch in the ON position.
Check if the diagnostic code for the alarm is active. Expected Result:The diagnostic code is NO longer active. Results:
YES - The diagnostic code is NO longer 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
NO - The diagnostic code