Troubleshooting

DTC P2123 Throttle/Pedal Position Sensor/Switch "D" Circuit High Input

DTC Detection Condition:

CIRCUIT DESCRIPTION

HINT:
- This is repair procedure of "accelerator pedal position sensor".
- This electrical throttle system is no used throttle cable.
- This accelerator pedal position sensor is non-contact type.

The throttle position sensor is mounted in the accelerator pedal to detect the opening angle of the accelerator pedal. Since this sensors is electronically controlled with hall elements, accurate control and reliability can be obtained. It have the 2 sensors to detect the accelerator position and a malfunction of the accelerator pedal position sensor.

In the accelerator pedal position sensor, the voltage applied to pedal terminals VPA and VPA2 of the ECM changes between 0 V and 5 V, in proportion to the opening angle of the accelerator pedal. The VPA is a signal to indicate the actual accelerator pedal opening angle which is used for the engine control, and the VPA2 is a signal to indicate the information about the opening angle which is used for detecting a malfunction. 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 DTCs is stored, the throttle valve is locked at a certain opening angle. Also, the whole electronically controlled throttle operation is cancelled until the system returns to normal and the ignition switch is turned OFF. However, the maximum opening angle of the accelerator pedal is limited to 22° when either of the VPA or VPA2 circuit is normal.






HINT: After confirming DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138 use the OBD II scan tool or the hand-held tester to confirm the accelerator pedal opening percentage.

Wiring Diagram:

INSPECTION PROCEDURE

HINT: Read freeze frame data using hand-held tester or the OBD II scan tool, as freeze frame data records the engine conditions when a malfunction is detected When troubleshooting this is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

Step 1:

Step 2 - 4:

Step 5:

Hand-held tester:

Step 1:

Step 2 - 3:

Step 4:

OBD II scan tool (excluding hand-held tester):