EDGE-CUTTING 4T6617 - Caterpillar

Illustration 1 g03616338
Schematic of the 8 V supply circuit
The parking brake oil pressure sensor supply is supplied by the Power Train Electronic Control Module (ECM). The sensor supply provides +8 V to operate the parking brake oil pressure sensor. The CID 0041 FMI 04 diagnostic code is recorded when the ECM reads the voltage of the 8 V supply circuit (wire 117-OR(Orange)) as lower than normal.The Monitoring System is connected to the Power Train Electronic Control Module (ECM) via the CAT Data Link.The following causes could signal this diagnostic code:
The sensor has failed
The sensor supply circuit is shorted to a ground source
The ECM may have failed, but is unlikelyTest Step 1. CHECK THE SENSOR
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the sensor from the machine harness.
Check to see if the CID 0041 FMI 04 code is still active. Expected Result:CID 0041 FMI 04 is not active.Results:
YES - CID 0041 FMI 04 is not active. The harness circuit is correct. The sensor has failed.Repair: Replace the faulty sensor.STOP
NO - CID 0041 FMI 04 is still active. The machine harness may be shorted to ground. Proceed to Test Step 2.Test Step 2. CHECK FOR A SHORT TO GROUND
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness connector J1 from the Power Train ECM.
At the harness connector for the Power Train ECM, measure the resistance between frame ground and contact J1-44 (wire 117-OR(Orange)) for the sensor supply circuit. Expected Result:The resistance is greater than 5 ohms.Results:
YES - The resistance is greater than 5 ohms. The machine harness circuit resistance is correct. The ECM may have failed.Repair: Using the Caterpillar Electronic Technician (ET) service tool, if available, perform a wiggle test on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness.If the diagnostic code is still active and the cause cannot be found, the ECM may have failed. Prior to replacing an ECM, always contact your dealerships Technical Communicator for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found, replace the ECM. Refer to Systems Operation Troubleshooting Testing and Adjusting, "Electronic Control Module (Power Train) - Replace".STOP
NO - The resistance is less than 5 ohms. The machine harness has failed.Repair: The 117-OR(Orange) wire is shorted to ground in the machine harness. Refer to the complete Electrical System Schematic for your machine. Check all harness connectors that are in the power supply circuit. Ensure that the connectors are clean and secure. Repair or replace the machine harness.STOP