DTC Troubleshooting: P2138 (37)

DTC P2138:  APP sensor A/B Incorrect Voltage Correlation

1.Turn the ignition switch ON (II).

2.Do the DTC CLEAR in the CLEAR MENU with the HDS.

3.Open the throttle to full position several times.

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

Is DTC P2138 indicated?


YES - Go to 5.


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


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

Are they the same voltage?


YES - Go to 6.


NO - Go to 11.


6.Turn the ignition switch OFF, and wait 10 seconds.

7.Connect the ECM test harness and the test pin box to the wire harness only, not to the ECM.

8.Check for continuity between test pin box terminals No. 63 and No. 79.

Is there continuity?


YES - Go to 9.


NO - Go to 18.

9.Disconnect the throttle body 6P connector.

10.Check for continuity between test pin box terminals No.63 and No.79.

Is there continuity?


YES - Repair short in the wire between the ECM connector No.3 terminal No. 34 (test pin box terminal No. 63) and ECM connector No. 3 terminal No. 50 (test pin box terminal No. 79), then go to 13.


NO - Go to 12.


11.Turn the ignition switch OFF.

12.Replace the APP sensor.

13.Turn the ignition switch ON (II).

14.Do the ECM RESET in the CLEAR MENU with the HDS.

15.Do the ETCS learn procedure.

16.Open the throttle to full position several times.

17.Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P2138 indicated, check for poor connections or loose terminals at the APP sensor and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Troubleshooting is complete.n

18.Substitute a known-good ECM.

19.Open the throttle to full position several times.

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

Are any Temporary DTCs or DTCs indicated?


YES - If DTC P2138 indicated, check for poor connections or loose terminals at the APP sensor and the ECM, then go to 1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC troubleshooting.


NO - Replace the original ECM.