ROLLER 3J1689 - Caterpillar

Illustration 1 g02677141
Schematic of the rear axle oil temperature sender
Table 1
SENDER TEMERATURE RANGE     TEMP     OHMS    
HIGH    
150° C (302° F)     18    
MID POINT    
95° C (203° F)     80    
LOW    
−40° C (−40° F)     34000    Note: Results will vary due to sender temperature.This diagnostic code is recorded when the ECM reads the signal voltage of the rear axle oil temperature sender and the voltage is too high. The operating range for the output voltage of the sender is approximately 0.5 DCV to 5 DCV.The possible causes of this diagnostic code are listed here:
The sender has failed.
The return circuit of the sender is open in the machine harness.
The signal circuit in the machine harness is shorted to a source of positive voltage.
The signal circuit in the machine harness is open or the sender is disconnected.
The ECM has failed. The ECM failing is unlikely. Test Step 1. CHECK THE SENDER.
Turn the disconnect switch and the key start switch to the ON position.
Disconnect the machine harness connector from the sender.
At the sender connector, measure the resistance between the signal contact 1 (wire J854-YL) and the return contact 2 (wire L740-BR). Expected Result:The resistance is between 18 ohms and 34000 ohms.Results:
NOT OK - The resistance is NOT between 18 ohms and 34000 ohms.Repair: Replace the sender.STOP
OK - The resistance is between 18 ohms and 34000 ohms. The ECM may have failed or the harness has failed. Proceed to Test Step 2.Test Step 2. CHECK THE RETURN CIRCUIT OF THE HARNESS.
The sender remains disconnected.
Turn the disconnect switch (if equipped) and the key start switch to the OFF position.
Disconnect the J1 and J2 machine harness connectors from the ECM.
Measure the resistance of the return circuit between contact 2 (wire L740-BR) of the machine harness for the sender and contact J1-21 of the machine harness for the ECM. Expected Result:The resistance is less than 5 ohms. Results:
OK - The resistance is less than 5 ohms. The harness resistance is correct. Proceed to Test Step 3.
NOT OK - The resistance is greater than 5 ohms. The ground circuit in the harness has failed. There is an open circuit between the ground contact and frame ground. Repair: Repair the machine harness or replace the machine harness. STOPTest Step 3. CHECK FOR A SHORTED HARNESS
The sender and the ECM remain disconnected from the machine harness.
The disconnect switch and the key start switch remain in the OFF position.
At the machine harness connector for the ECM, measure the resistance between the signal contact J1-53 (wire J854-YL) and all contacts that are used in the machine harness connector for the ECM. Expected Result:Each resistance measurement is greater than 5000 ohms. Results:
OK - Each resistance measurement is greater than 5000 ohms. The ECM has failed.Repair: It is unlikely that an ECM has failed. Exit this procedure. Perform this diagnostic code procedure again. If the failure is not found, replace the ECM. Refer to Testing and Adjusting, "Electronic Control Module (ECM) - Replace".