RENR5042-02 145 Troubleshooting Section B. Disconnect the suspect sensor from the harness at the sensor connector. An 03 diagnostic code should be active for the suspect sensor. C. Turn the keyswitch to the ON position. Wait at least 15 seconds for activation of the diagnostic codes. C. Check the operation of the ECM by creating a short at the ECM. a. Install a wire jumper between the terminals for the sensor signal and the sensor return. D. Access the “Active Diagnostic Codes” screen on the electronic service tool and check for an active 03 diagnostic code for the suspect sensor. b. Monitor the “Active Diagnostic Code” screen on the electronic service tool.
Wait at least 15 seconds for activation of the code. E. Turn the keyswitch to the OFF position. Expected Result: An 04 diagnostic code should be active when the wire jumper is installed. An 03 diagnostic code is now active for the suspect sensor. c. Remove the wire jumper and reconnect all wires. Results: Expected Result: OK An 04 diagnostic code was active before disconnecting the sensor. An 03 diagnostic code became active after the sensor was disconnected. An 03 diagnostic code is active when the sensor signal wire is removed from the ECM connector. An 04 diagnostic code is active when the signal wire is connected to the sensor return. Repair:
Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Verify that there are no active diagnostic codes for the sensor. If there are no active diagnostic codes for the sensor, permanently install the new sensor. Clear any logged diagnostic codes. Results: OK – The ECM is working properly. The problem is in the wiring between the ECM and the sensor connector. Verify that the repair eliminates the problem. Repair: If the code is active for more than one sensor, the problem is most likely in the return wire for the sensor. Repair the return wire for the sensor or replace the harness. STOP. Not OK – The 04 diagnostic code is still present.
Leave the sensor disconnected. Proceed to Test Step 7. If the code is only active for one sensor, the problem is most likely in the signal wire for the sensor. Repair the signal wire for the sensor. Test Step 7. Check the Operation of the ECM STOP. A. Turn the keyswitch to the OFF position. Not OK – One of the following conditions exists: The 03 diagnostic code is not active when the sensor signal wire is disconnected. The 04 diagnostic code is not active when the wire jumper is installed. B. Check the operation of the ECM by creating an open at the ECM. a. Remove the signal wire for the suspect sensor from the P2connector. Repair: Replace the ECM.
Refer to Troubleshooting, “Replacing the ECM”. Verify that the problem is resolved. b. Remove the sensor return from terminal P2-30. Note: Disconnecting the sensor return from the ECM will generate an 03 diagnostic code for all sensors that are connected to the sensor return. Troubleshoot the original diagnostic code. Delete the logged diagnostic codes when you are finished. STOP. c. Turn the keyswitch to the ON position. Monitor the “Active Diagnostic Code” screen on the electronic service tool. Wait at least 15 seconds for activation of the code.