PLATE 9S6241 - Caterpillar

Illustration 3 g00825608
ECM connectors (wire side)
Turn the keyswitch to the OFF/RESET position.
Disconnect the appropriate ECM connector for the suspect sensor. Thoroughly inspect both halves of the connector for signs of corrosion and/or moisture.
Reconnect the ECM connector.
Turn the keyswitch to the ON position. Monitor the "Active Diagnostic Code" screen on ET. Wait at least 15 seconds for activation of the code.An open circuit diagnostic code should be active for the suspect sensor. Note the sensor that has the open circuit diagnostic code.
Remove the signal wire and the return wire for the suspect sensor from the appropriate ECM connector. Refer to Illustration 3.Note: Active open circuit diagnostic codes will be generated for any other temperature sensors that share the return for the suspect sensor.
Install a jumper wire with Deutsch sockets on each end between the terminal for the suspect sensor signal and the return for the suspect sensor.Note: A short circuit diagnostic code should be active when the jumper wire is installed.
Monitor the "Active Diagnostic Code" screen on ET. Wait at least 15 seconds for activation of the code.Expected Result:An open circuit diagnostic code is active when the wires are removed from the ECM connector. A short circuit diagnostic code is active when the jumper wire is installed.Results:
OK - The ECM is working properly. Proceed to Test Step 8.
Not OK - One of the following conditions exists: The open circuit diagnostic code is not active when the harness is disconnected. The short circuit diagnostic code is not active when the jumper wire is installed.Repair: Perform the following repair:
Temporarily connect a test ECM.
Remove all jumper wires and reconnect all connectors and wires.
Recheck the system for active diagnostic codes.
Repeat this test step.
If the problem is resolved with the test ECM, reconnect the suspect ECM.
If the problem returns with the suspect ECM, replace the ECM.
Verify that the repair eliminates the problem.STOPTest Step 8. Bypass the Wiring Harness between the ECM and the Sensor Connector
Turn the keyswitch to the OFF/RESET position.
Remove the sensor signal wire from the ECM connector.
Disconnect the sensor connector.
Remove the signal wire (terminal 1) from the sensor connector on the engine harness.
Fabricate a jumper wire that is long enough to reach from the ECM to the sensor connector with Deutsch sockets on both ends.
Insert one end of the jumper wire into the signal terminal of the ECM connector. Insert the other end of the jumper wire into terminal 1 of the sensor connector on the engine harness.
Reconnect the sensor connector.
Turn the keyswitch to the ON position.
Monitor the "Active Diagnostic Codes" screen on ET for either the open circuit diagnostic code for the sensor or the short circuit diagnostic code for the sensor.Expected Result:No diagnostic codes are present for the suspect sensor when the jumper wire is installed.Results:
OK - There is a problem in the wiring harness between the ECM and the sensor connector.Repair: Repair the circuit and clear all diagnostic codes.Verify that the repair eliminates the problem.STOP
Not OK - Restart this procedure and carefully perform each step.STOP