JACKET WATER HEATER GROUP 4N9044 - Caterpillar

Illustration 1 g01238290
Schematic of the remote control brake lightThis diagnostic code is associated with the remote control brake light. The FMI 05 means that the Power Train ECM has determined that the current of the remote control brake light is below normal. The possible causes of this diagnostic code are:
The energize circuit of the remote control brake light is open.
The return circuit of the remote control brake light is open.
The remote control brake light 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 1926 FMI 05 is active before performing this procedure.Note: Use the 146-4080 Digital Multimeter for the measurements in this procedure.System Response:When this diagnostic code occurs, the remote control brake light is inoperable.Test Step 1. CHECK THE REMOTE CONTROL BRAKE LIGHT
Turn the disconnect switch and the key start switch to the ON position. Do not start the engine.
Disconnect the remote control brake light from the machine harness.
At the machine harness connector for the remote control brake light, place a jumper wire from contact A (wire EL457-WH) to contact B (wire T945-GY).
Observe the status of the CID 1926 FMI 05.Expected Result:The CID 1926 FMI 05 remains active. The FMI has not changed and the "05" is still active.Results:
YES - The diagnostic code remains active. The jumper wire does not affect the diagnostic code. Proceed to Test Step 2.
NO - The diagnostic is no longer active. The remote control brake light has failed.Repair: Replace the remote control brake light. Verify that the new remote control brake light corrects the problem.STOPTest Step 2. CHECK THE HARNESS FOR AN OPEN CIRCUIT
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector(s) from the ECM.
The jumper wire that was installed in the previous Test Step remains in place.
At the machine harness connector, measure the resistance from signal contact J2-3 (wire EL457-WH) to contact J2-4 (wire T945-GY).Expected Result:The resistance is 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 is greater than 5 ohms. The resistance measurement is not correct. There is an open circuit in the machine harness.Repair: The open is in wire EL457-WH or in wire T945-GY 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 of the harness connectors and clean the harness connectors.
Reconnect all harness connectors.
Turn the disconnect switch and the key start switch to the ON position.
Operate the machine.
Check the status of the CID 1926 FMI 05.Expected Result:The CID 1926 FMI 05 is active. Results:
YES - The CID 1926 FMI 05 is active. The diagnostic code has not been corrected. The ECM may have failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and