BYPASS-OIL COOLER 3R9266 - Caterpillar

Illustration 1 g02140406
Schematic of the sensor supply voltageThe diagnostic code is recorded when the interface module indicates that the voltage of the sensor supply circuit is too low. Possible causes of this diagnostic code are listed below:
The output of sensor supply shorted to ground.
A sensor has failed. Test Step 1. CHECK THE VOLTAGE AT THE MACHINE ECM.
Turn the disconnect switch and the key start switch to the ON position.
Check the voltage at the Machine ECM from contact J1-27 (sensor supply) to contact J1-14 (return). Use the 7X-1710 Cable Probes to measure the voltage. Do NOT disconnect the machine harness from the Machine ECM.
Check the voltage at the Machine ECM from contact J1-27 (sensor supply) to contact J1-2 (return). Use the 7X-1710 Cable Probes to measure the voltage. Do NOT disconnect the machine harness from the Machine ECM. Expected Result:The voltage is 8.0 0.5 VDC.Results:
OK - The voltage is 8.0 0.5 VDC. The sensor supply voltage is correct. Verify that the diagnostic code is present. If the diagnostic code is still present, the Machine ECM has failed.Repair: A failure of the Machine ECM is unlikely. Exit this procedure and perform this procedure again. Also, recheck if the diagnostic code is active. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Module - Replace".STOP
NOT OK - Voltage is NOT 8.0 0.5 VDC. The voltage is less than 8.0 0.5 VDC. The sensor supply voltage is NOT correct. 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 from the Machine ECM.
At the harness connector for the Machine ECM, measure the resistance between frame ground and contact J1-27 of the sensor supply circuit. 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 Machine ECM has failed.Repair: A failure of the ECM is unlikely. Exit this procedure and perform this procedure again. Also, recheck if the diagnostic code is active. If the cause of the diagnostic code is not found, replace the Machine ECM. See Testing and Adjusting, "Module - Replace".STOP
NOT OK - The resistance is less than 5000 ohms. The machine harness or a sensor has failed. Proceed to Test Step 3.Test Step 3. DISCONNECT THE SENSOR.
The key start switch and the disconnect switch remain in the OFF position.
Disconnect the sensors from the machine harness one at a time.
After disconnecting each of the sensors, check the resistance from frame ground to contact J1-27 (sensor supply) of the machine harness connector for the ECM.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 sensor that was disconnected has failed.Repair: Replace the sensor.STOP
NOT OK - The resistance is less than 5000 ohms. The resistance is less than 5000 ohms after all the sensors have been disconnected from