LINES GP- 3157286 - Caterpillar

Illustration 1 g02559836
Connections of the Autolube Pressure Sensor
This diagnostic code is associated with the Autolube Pressure Sensor. This diagnostic code is recorded when the ECM reads the signal from the sensor (wire E456-WH(White)) or (wire C432-GN(Green)) as being shorted to the +battery. The signal (wire E456-WH(White)) connects to contact J1-36 of the ECM and the signal (wire C532-GN(Green)) connects to contact J1-37 of the ECM.Possible causes of the diagnostic code are listed:
The return circuit is open.
The signal circuit is open or the sensor is disconnected.
The signal circuit is shorted to the +battery.
The sensor has failed.
The ECM has failed. The failure of the ECM is unlikely.Before performing this procedure, inspect the harness connectors that are involved in the circuit. Poor connections can often be the cause of a problem in an electrical circuit. Verify that all of the connections in the circuit are clean and secure. If a problem with a connection is found, correct the problem and verify that this diagnostic code is active before performing this procedure.The following test procedure may create other diagnostic codes. Ignore these created diagnostic codes and clear the diagnostic codes when the original diagnostic code has been corrected. Ensure that the diagnostic code of CID 0379 FMI 03 is active before performing this procedure.Test Step 1. CHECK FOR AN OPEN IN THE RETURN CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the sensor from the machine harness.
At the machine harness connector for the sensor, measure the resistance from contact 2 (wire A273-BK(Black)) to ground. Expected Result:The resistance measurement should measure less than 5 ohms.Results:
OK - The resistance measurement is less than 5 ohms. The return circuit is correct. Proceed to Test Step 2.
NOT OK - The resistance that is measured is not correct.Repair: There is an open in the machine harness. The open is in the return circuit. Repair the harness or replace the harness.STOPTest Step 2. CHECK FOR AN OPEN IN THE SIGNAL CIRCUIT.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the J1 and J2 machine harness connector from the ECM.
At the machine harness connector for the sensor, install a jumper wire from contact 3 to contact 2 (wire A273-BK(Black)).
At the machine harness connector J1, measure the resistance from signal contact at the ECM to J1-70 (wire A273-BK(Black)). Expected Result:The resistance should measure less than 5 ohms.Results:
OK - The resistance measures less than 5 ohms. Proceed to 3.
NOT OK - The resistance measurement is greater than 5 ohms.Repair: There is an open in the signal circuit. Repair the harness or replace the harness.STOPTest Step 3. CHECK THE SIGNAL CIRCUIT FOR A SHORT.
The disconnect switch and the key start switch remain in the OFF position.
The machine harness connectors J1 and J2 remain disconnected.
Remove the jumper wire from signal contact 3 to contact 2 (wire A273-BK(Black)).
At the J1 and J2 machine harness connectors for the ECM, measure the resistance for the signal contact of the sensor to all other J1 and J2 contacts. Expected