Troubleshooting

DTC P2121 ACCELERATOR PEDAL POSITION SENSOR RANGE/ PERFORMANCE PROBLEM*

*: Only for sequential manual transmission vehicle.

CIRCUIT DESCRIPTION

DTC Detection Condition:

The accelerator pedal position sensor is mounted on the accelerator pedal and has the 2 signal outputs (elements) that are used for engine control and detecting malfunctions in the sensor.

The accelerator pedal position sensor and accelerator pedal are connected by the accelerator wire and the voltage applied to the terminals VPA and VPA2 of the ECM changes between 0 V and 5 V in proportion to the opening angle of the accelerator pedal. VPA signals are used to detect actual accelerator pedal angles, which is useful for engine control. VPA2 signals are used for detecting malfunctions in VPA.

The ECM judges the current opening angle of the accelerator pedal from these signals input from terminals VPA and VPA2 and the ECM controls the throttle motor based on these signals.

If this DTC is stored, the ECM shuts down the power for the throttle motor and the magnetic clutch, and the throttle valve is fully closed by the return spring.

However, the opening angle of the throttle valve can be controlled by the accelerator pedal through the throttle cable.

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Condition:

Typical Malfunction Thresholds:

The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal position sensor is mounted on the accelerator pedal and has the 2 signal outputs (elements) that are used for engine control and detecting malfunctions in the sensor. When the difference between the voltage output of VPA and VPA2 deviate from the standard, the ECM concludes that the accelerator pedal position sensor is malfunctioning. The ECM turns on the MIL and a DTC is set.

Wiring Diagram:

Step 1 - 2:

Step 3:

INSPECTION PROCEDURE

HINT:
- If DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
- Read freeze frame data using the hand-held tester or the OBD II scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.