FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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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.

1. Turn the ignition switch 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 OFF.
6. Disconnect the CMP sensor A 3P connector.
7. Turn the ignition switch ON (II).




8. Measure 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 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 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 OFF.
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 ASP 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 OFF.
17. Replace CMP sensor A.
18. Reconnect all connectors.
19. Turn the ignition switch ON (II).
20. Reset the ECM with the HDS.
21. Do the ECM idle learn procedure.
22. Check for Temporary DTCs or DTCs with the HDS.

Are any Temporary DTCs or DTCs indicated?

YES - If DTC P0340 is indicated, check for poor connections or loose terminals at CMP sensor A and the ECM, then go to step 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.

NO - Troubleshooting is complete.

23. Update the ECM if it does not have the latest software, or substitute a known-good ECM.
24. 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, 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. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.