Troubleshooting

DTC P2120 THROTTLE/PEDAL POSITION SENSOR/SWITCH "D" CIRCUIT*

*: 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.






HINT: After confirming DTC P2120, use the OBD II scan tool or the hand-held tester to confirm the throttle valve opening angle (voltage).

MONITOR DESCRIPTION

Monitor Strategy:

Typical Enabling Condition:

Typical Malfunction Thresholds:

Component Operating Range:

The accelerator pedal position sensor is equipped with 2 signal outputs (elements), VPA and VPA2. 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. These elements vary their resistance according to how much the accelerator pedal is depressed. The ECM applies a regulated reference voltage to the throttle position sensor "+" terminal and calculates the amount of the accelerator pedal depression based on the voltages present at the throttle position sensor "signal terminals. When the amount of the accelerator pedal depression is small, the output voltages of these elements are low. When it is large, the output voltages are high. If the ECM detects that the output voltage of the element(s) is out of the normal range, the ECM will conclude that the accelerator pedal position sensor is malfunctioning and set a DTC.

Wiring Diagram:

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.

Step 1 - 3:

Step 4 - 5:

Hand-held tester

Step 1:

Step 2 - 3:

Step 4:

OBD II scan tool (excluding hand-held tester)