DTC Troubleshooting

Control System DTCs

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 How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-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 Pending or Confirmed DTCs with the HDS.

Is DTC P2138 indicated?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the APP sensor and the ECM.

2. APP sensor signal check:

APP sensor signal check
-1. Check APP SENSOR A and APP SENSOR B in the DATA LIST with the HDS

Are they the same voltage?
-YES- Go to step 3.
-NO- Replace the APP sensor Service and Repair, then do the repair verification.

3. Determine possible failure area (ECM, others):

Determine possible failure area (ECM, others)
-1. Turn the ignition switch to LOCK (0)

-2. Jump the SCS line with the HDS.

-3. Disconnect the following connector.





-4. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Go to step 4.
-NO- Update the ECM ECM/PCM Update if it does not have the latest software, or substitute a known-good ECM Service and Repair, then do the repair verification.

4. Shorted wire check (APS1 line to APS2 line):

Shorted wire check (APS1 line to APS2 line)
-1. Disconnect the following connector.





-2. Check for continuity between test points 1 and 2.









Is there continuity?
-YES- Repair a short in the APS1, APS2 wires between ECM connector terminals A28 (APS1 line) and A29 (APS2 line), then do the repair verification.
-NO- The APS1 and APS2 wires are OK. Replace the APP sensor Service and Repair, then do the repair verification.

Repair verification:

-1. Turn the ignition switch to LOCK (0).

-2. Reconnect all connectors.

-3. Turn the ignition switch to ON (II).

-4. Reset the ECM with the HDS How To Troubleshoot The Fuel And Emissions Systems.

-5. Do the ECM idle learn procedure ECM/PCM Idle Learn Procedure.

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

-7. Turn the ignition switch to ON (II).

-8. Press the accelerator pedal to the floor.

-9. Check for Pending or Confirmed 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 Service and Repair. then recheck. If the ECM was substituted, go to step 1.
-NO- Troubleshooting is complete. If the ECM was substituted, replace the original ECM Service and Repair. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.