DTC Troubleshooting

DTC Troubleshooting: P0340

DTC P0340: CMP Sensor A No Signal

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information. Initial Inspection and Diagnostic Overview

1. Turn the ignition switch to ON (II)

2. Clear the DTC with the HDS.

3. Start the engine.

4. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0340 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at CMP sensor A and the ECM.


5. Turn the ignition switch to LOCK (0).

6. Disconnect the CMP sensor A 3P connector.

7. Turn the ignition switch to ON (II)

8. Measure the voltage between CMP sensor A 3P connector terminal No. 3 and body ground.

Is there battery voltage?
YES - Go to step 9.

NO - Repair open in the wire between CMP sensor A and the No. 3 ALTERNATOR (10 A) fuse, then go to step 18.






9. Measure the voltage between CMP sensor A 3P connector terminal No. 1 and body ground.

Is there about 5 V?
YES - Go to step 10.

NO - Go to step 11.






10. Measure the voltage between CMP sensor A 3P connector terminals No. 2 and No. 3.

Is there battery voltage?
YES - Go to step 16.

NO - Repair open in the wire between CMP sensor A and G101, then go to step 18.






11. Turn the ignition switch to LOCK (0).

12. Jump the SCS line with the HDS.

13. Disconnect ECM connector C (44P).

14. Check for continuity between ECM connector terminal C41 and body ground.

Is there continuity?
YES - Repair short in the wire between the ECM (C41) and CMP sensor A, then go to step 18.

NO - Go to step 15.






15. Check for continuity between CMP sensor A 3P connector terminal No. 1 and ECM connector terminal C41.

Is there continuity?
YES - Go to step 23.

NO - Repair open in the wire between the ECM (C41) and CMP sensor A, then go to step 18.






16. Turn the ignition switch to LOCK (0).

17. Replace CMP sensor A. CMP Sensor A Replacement

18. Reconnect all connectors.

19. Turn the ignition switch to ON (II)

20. Reset the ECM with the HDS.

21. Do the ECM idle learn procedure. ECM Idle Learn Procedure

22. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0340 indicated?
YES - Check for poor connections or loose terminals at CMP sensor A and the ECM, then go to step 1.

NO - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.


23. Reconnect all connectors.

24. Update the ECM if it does not have the latest software, ECM Update or substitute a known-good ECM. Initial Inspection and Diagnostic Overview

25. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P0340 indicated?
YES - Check for poor connections or loose terminals at CMP sensor A and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then recheck. If the ECM was substituted, go to step 1.

NO - If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM. Service and Repair If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.