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P2123

DTC P2120 Throttle / Pedal Position Sensor / Switch "D" Circuit
DTC 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

DESCRIPTION




DTC Detection Conditions (Part 1):




DTC Detection Conditions (Part 2):






HINT:
- The Electronic Throttle Control System (ETCS) does not use a throttle cable.
- The accelerator pedal position sensor is a non-contact type.
- The ETCS does not use a throttle cable.

The accelerator pedal position sensor is mounted on the accelerator pedal bracket and has 2 sensor circuits: VPA (main) and VPA2 (sub). This sensor uses Hall-effect elements 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 V and 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 accelerator pedal position 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 accelerator pedal position sensor voltage by entering the given menus on the intelligent tester: DIAGNOSIS / ENHANCED OBD II/ DATA LIST / PRIMARY / ACCEL POS #1 and ACCEL POS #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 (Part 1):




Component Operating Range (Part 2):




When either of the output voltage of VPA or VPA2 deviates from the standard range, or the difference between the output voltage of the 2 sensor circuits is less than the threshold, the ECM determines that there is a malfunction in the accelerator pedal position sensor. The ECM then illuminates the MIL and sets a DTC.

Example:
When the output voltage of VPA drops below 0.2 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 started again.

FAIL-SAFE
When any of DTCs P2120, P2122, P2123, P2125, P2127, P2128 and P2138 is 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 turns the engine switch off.

Wiring Diagram:






Step 1-2:




Step 3-5:




INSPECTION PROCEDURE

HINT:
- Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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.
- These DTCs relate to the accelerator pedal position sensor.