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 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 12.


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

7. Jump the SCS line with the HDS.

8. Disconnect ECM connector A (44P).

9. Check for continuity between ECM connector terminals A17 and A18.

Is there continuity?
YES - Go to step 10.

NO - Go to step 22.






10. Disconnect the APP sensor 6P connector.

11. Check for continuity between ECM connector terminals A17 and A18.

Is there continuity?
YES - Repair short in the wires between ECM connector terminals A17 (APSA line) and A18 (APSB line), then go to step 14.

NO - Go to step 13.






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

13. Replace the accelerator pedal module. Service and Repair

14. Reconnect all connectors.

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

16. Reset the ECM with the HDS.

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

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

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

20. Press the accelerator pedal to the floor.

21. 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.


22. Reconnect all connectors.

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

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

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

26. Press the accelerator pedal to the floor.

27. 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 24. 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.