DTC Advanced Diagnostics: P2138 (3.0L Engine)
DTC P2138: Accelerator Pedal Position (APP) Sensor A/B Incorrect Voltage Correlation
General Description
The diagnosis related to the electric throttle control system is done during the vehicle ON mode and OFF (LOCK) mode. The powertrain control module (PCM) opens and closes the throttle actuator to monitor the performance of the throttle body. If the difference between the accelerator pedal position (APP) sensor A output value and the APP sensor B output value is large, the PCM detects a malfunction and stores a DTC.
Monitor Execution, Sequence, Duration, DTC Type
| Execution | Continuous |
| Sequence | None |
| Duration | 110 milliseconds or more |
| DTC Type | One drive cycle, MIL on |
Enable Conditions
| Condition | |
|---|---|
| Vehicle | ON mode |
Malfunction Threshold
The difference between the accelerator pedal position (APP) sensor A output value and the APP sensor B output value is more than 2 deg. for at least 110 milliseconds.
Possible Cause
- APP sensor failure
Diagnosis Details
Conditions for setting the DTC
When a malfunction is detected, the MIL comes on and a Pending DTC, a Confirmed DTC, the freeze data, and the on-board snapshot are stored in the PCM memory.
Conditions for clearing the DTC
The MIL is cleared if the malfunction does not return in three consecutive trips in which the diagnostic runs. The MIL, the Pending DTC, the Confirmed DTC, the freeze data, and the on-board snapshot can be cleared with the scan tool clear command.