LINES GP-PUMP 4790788 - Caterpillar

Illustration 1 g01853774
Schematic of the transmission oil temperature sensorThis diagnostic code is associated with the transmission oil temperature sensor.This diagnostic code is recorded when the ECM reads the sensor signal voltage and the voltage is too low.The possible causes of this failure are listed here:
The sensor has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. This is unlikely.System Response:This failure causes the transmission oil temperature sensor to indicate the minimum value or the transmission oil temperature sensor may intermittently indicate the minimum value.Test Step 1. CHECK THE SENSOR.
Disconnect the machine harness from the sensor.Expected Result:The diagnostic code changes from CID 0177 FMI 04 to CID 0177 FMI 03.Results:
OK - The diagnostic code changed to CID 0177 FMI 03. This indicates that the failure is no longer present. The sensor has failed.Repair: Replace the sensor.STOP
NOT OK - The diagnostic code of CID 0177 FMI 04 remained active. This indicates that the failure remains present. The sensor is not causing the failure. Proceed to Test Step 2.Test Step 2. CHECK THE HARNESS.
The sensor remains disconnected from the machine harness.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
At the harness connector for the sensor, measure the resistance between the signal contact C (wire G460-GN) and frame ground.Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The harness circuit resistance is correct. The ECM has failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this CID 0177 FMI 04 procedure again. If the failure is not found, replace the ECM. See the Testing and Adjusting, "Electronic Control Module(ECM) - Replace" Story in this manual for additional information.STOP
NOT OK - The resistance is less than 5000 ohms. The machine harness has failed. There is a short between frame ground and the signal circuit in the machine harness.Repair: Repair the machine harness or replace the machine harness.STOP