Troubleshooting
DTC P2123 Throttle/Pedal Position Sensor/Switch "D" Circuit High InputHINT: There is a repair procedure for the accelerator pedal position sensor.
CIRCUIT DESCRIPTION
Detection Item:
HINT: This Electrical Throttle Control System (ETCS) does not use a throttle cable.
The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal position sensor has 2 sensor elements/signal outputs: VPA and VPA2. VPA is used to detect the actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA. Voltage of VPA and VPA2 changes between 0 V to 5 V depending on the accelerator pedal angle.
The ECM monitors the accelerator pedal angle from VPA and VPA2 signal outputs, and controls the throttle motor based on these signals.
HINT: After confirming DTC P2120, P2122, P2123, P2125, P2127, P2128 and P2138, use the hand-held tester or the OBD II scan tool to confirm the accelerator pedal position sensor output voltage.
MONITOR DESCRIPTION
Monitor Strategy:
Typical Enabling Conditions:
Typical Malfunction Thresholds:
Component Operating Range:
When VPA or VPA2 deviates from the standard, or the difference between the voltage outputs of the two sensors is less than threshold, the ECM concludes that there is a defect in the accelerator pedal position sensor. The ECM turns on the MIL and a DTC is set.
Example: When the voltage output of the VPA is below 0.2 V or exceeds 4.8 V.
FAIL SAFE
The accelerator pedal position sensor has two (main and sub) sensor circuits. If a malfunction occurs in either of the sensor circuits, the ECM detects the abnormal signal voltage difference between the two sensor circuits and switches to limp mode. In limp mode, the remaining circuit is used to calculate the accelerator pedal opening to allow the vehicle to continue driving.
If both circuits malfunction, the ECM regards the opening angle of the accelerator pedal to be fully closed. In this case, the throttle valve will remain closed as if the engine is idling.
If a "pass" condition is detected and then the ignition switch is turned OFF, the fail-safe operation will stop and the system will return to normal condition.
Wiring Diagram:
INSPECTION PROCEDURE
HINT: 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, as well as other data from the time when a malfunction occurred.
Step 1 - 2:
Step 3 - 4:
Step 5 - 6:
Hand-held tester
Step 1 - 2:
Step 3 - 4:
Step 5:
OBD II scan tool (excluding hand-held tester)