DTC Troubleshooting

DTC Troubleshooting: P2138

DTC P2138: APP Sensor A/B (TP Sensor D/E) Incorrect Voltage Correlation

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. Press the accelerator pedal to the floor.

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

Is DTC P2138 indicated?
YES - Go to step 5.

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


5. Check APP SENSOR A and APP SENSOR B in the DATA LIST with the HDS.

Are they the same voltage?
YES - Go to step 6.

NO - Go to step 11.


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

7. Jump the SCS line with the HDS.

8. Disconnect the APP sensor 6P connector.

9. Disconnect ECM connector A (31P).

10. Check for continuity between ECM connector terminals A25 and A26.

Is there continuity?
YES - Repair short in the wire between the ECM terminals (A25, A26), then go to step 13.

NO - Go to step 21.






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

12. Replace the APP sensor. Service and Repair

13. Reconnect all connectors.

14. Turn the ignition switch to ON (II).

15. Reset the ECM with the HDS.

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

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

18. Turn the ignition switch to ON (II).

19. Press the accelerator pedal to the floor.

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

Is DTC P2138 indicated?
YES - Check for poor connections or loose terminals at the APP sensor 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.


21. Reconnect all connectors.

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

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

24. Turn the ignition switch to ON (II).

25. Press the accelerator pedal to the floor.

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

Is DTC P2138 indicated?
YES - Check for poor connections or loose terminals at the APP sensor and the ECM. If the ECM was updated, substitute a known-good ECM, Initial Inspection and Diagnostic Overview then go to step 23. 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.