RADIATOR & HYD OIL COOLER GP 9U4066 - Caterpillar

Illustration 1 g02159618
Schematic of the engine coolant temperature sensor.This diagnostic code is recorded when the ECM reads the signal voltage of the engine coolant temperature sensor and the voltage is too low. The operating range for the output voltage of the sensor is approximately 0 DCV to 5.0 DCV.The possible causes of this diagnostic code are listed here:
The sensor has failed.
The signal circuit in the machine harness is shorted to ground.
The ECM has failed. The failure of the ECM is unlikely. System Response:The diagnostic code of CID 0110 FMI 04 will be logged in the internal memory of the ECM. When the diagnostic code occurs, the following responses will occur.
The action alarm will sound.
The engine coolant gauge will display the maximum temperature.
A warning indicator is activated on the display.Test Step 1. CHECK THE SENSOR.
Disconnect the machine harness from the sensor. Expected Result:The diagnostic code changes from CID 0110 FMI 04 to CID 0110 FMI 03.Results:
OK - The diagnostic code changed from CID 0110 FMI 04 to CID 0110 FMI 03. The failure is no longer present. The sensor has failed. Repair: Replace the sensor.STOP
NOT OK - The diagnostic code remains. 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.
Disconnect the negative battery cable and turn the key start switch to the OFF position.
Disconnect the J1 machine harness connector from the ECM.
At the machine harness connector for the sensor, measure the resistance between the signal contact 1 (wire 492-GY) 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 may have failed. Repair: The ECM has failed. Exit this procedure, and perform this procedure again. If the failure is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". 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