P2138
DTC P2120 Throttle / Pedal Position Sensor / Switch "D" CircuitDTC P2122 Throttle / Pedal Position Sensor / Switch "D" Circuit Low Input
DTC P2123 Throttle / Pedal Position Sensor / Switch "D" Circuit High Input
DTC P2125 Throttle / Pedal Position Sensor / Switch "E" Circuit
DTC P2127 Throttle / Pedal Position Sensor / Switch "E" Circuit Low Input
DTC P2128 Throttle / Pedal Position Sensor / Switch "E" Circuit High Input
DTC P2138 Throttle / Pedal Position Sensor / Switch "D" / "E" Voltage Correlation
DTC Detection Condition:
DESCRIPTION
HINT: This ETCS (Electronic Throttle Control System) does not use a throttle cable.
The APP sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor is a non-contact type and uses Hall-effect elements in order to yield accurate signals even in extreme driving conditions, such as at high speeds as well as very low speeds. The voltage, which is applied to terminals VPA and VPA2 of the ECM, varies between 0.5 V and 4.5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A signal from VPA indicates the actual accelerator pedal opening angle (throttle valve opening angle) and is used for engine control. A signal from VPA2 conveys the status of the VPA circuit and is used to check the APP sensor itself. The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the signals from VPA and VPA2, and controls the throttle actuator according to these signals.
HINT: When any of these DTCs are set, check the APP sensor voltage by entering the following menus:
- Intelligent tester - Select: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ETCS / ACCEL POS #1 and ACCEL POS #2.
- Techstream: Powertrain / Engine and ECT / Data List / ETCS / Accelerator Position No. 1 and Accelerator Position No. 2.
HINT:
- Accelerator pedal positions are expressed as voltages.
- AP stands for Accelerator Pedal.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
When either output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltages of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the APP sensor. The ECM then illuminates the MIL and sets a DTC.
Example: When the output voltage of VPA drops below 0.4 V for more than 0.5 seconds when the accelerator pedal is fully depressed, DTC P2122 is set.
If the malfunction is not repaired successfully, a DTC is set 2 seconds after the engine is next started.
FAIL-SAFE
When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 are set, the ECM enters fail-safe mode. If either of the 2 sensor circuits malfunctions, the ECM uses the remaining circuit to calculate the accelerator pedal position to allow the vehicle to continue driving. If both of the circuits malfunction, the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the engine idles.
Fail-safe mode continues until a pass condition is detected, and the ignition switch is turned OFF.
Wiring Diagram:
Step 1:
Step 1(Continued)-2:
Step 2(Continued)-5:
Step 5(Continued):
INSPECTION PROCEDURE
HINT:
- These DTCs relate to the Accelerator Pedal Position (APP) sensor.
- Read freeze frame data using the intelligent tester or Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.