P2138
DTC P2138
CIRCUIT DESCRIPTION
The accelerator pedal position (APP) sensor 1 and APP sensor 2 are potentiometer type sensors, each with the following circuits:
- A 5-Volt reference circuit
- A low reference circuit
- A signal circuit
The control module provides the APP sensors a 5-Volt reference circuit and a low reference circuit. The APP sensors then provide the control module signal voltages proportional to pedal movement. The APP sensor 1 and the APP sensor 2 signal voltages are both low at rest and increase as the pedal is depressed. When the control module detects that the APP sensor 1 and the APP sensor 2 signal circuits are out of correlation, DTC P2138 sets.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation
CONDITIONS FOR RUNNING THE DTC
- DTC P2107 or P2108 are not set.
- The ignition is in the Crank or Run position.
- The ignition voltage is more than 5.23 volts.
- The communication between the throttle actuator control (TAC) module and the powertrain control module (PCM) must be valid.
CONDITIONS FOR SETTING THE DTC
The PCM detects that the difference between APP sensor 1 and APP sensor 2 is more than the predicted value.
ACTION TAKEN WHEN THE DTC SETS
- The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
- The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Freeze Frame and/or the Failure Records.
- The control module commands the TAC system to operate in the Reduced Engine Power mode.
- A message center or an indicator displays Reduced Engine Power.
- Under certain conditions the control module commands the engine OFF.
CONDITIONS FOR CLEARING THE DTC
- A current DTC Last Test Failed clears when the diagnostic runs and passes.
- A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
- Clear the DTC with a scan tool
TEST
