P2123
DTC P2120 Throttle / Pedal Position Sensor / Switch "D" CircuitDTC 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
HINT: This is the repair procedure for the "accelerator pedal position sensor".
DESCRIPTION
DTC Detection Condition:
HINT:
- This Electronic Throttle Control System (ETCS) does not use a throttle cable.
- This description is for the accelerator pedal position sensor.
The accelerator pedal position sensor is mounted on the accelerator pedal bracket. The accelerator pedal position sensor has 2 sensor elements/signal outputs: VPA1 and VPA2. VPA1 is used to detect the actual accelerator pedal angle (used for engine control) and VPA2 is used to detect malfunctions in VPA1. Voltage applied to VPA1 and VPA2 changes between 0 V and 5 V in proportion to the accelerator pedal angle.
The ECM monitors the accelerator pedal angle from VPA1 and VPA2 signal output, and controls the throttle motor based on these signals.
HINT: After confirming DTCs P2120, P2122, P2123, P2125, P2127, P2128 and P2138, use the intelligent 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 (Part 1):
Typical Malfunction Thresholders (Part 2):
Component Operating Range:
When VPA or VPA2 deviates from the standard, or the difference between the voltage output of the 2 sensors is less than the 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: The voltage output of the VPA is below 0.4 V or exceeds 4.8 V.
FAIL-SAFE
The accelerator pedal position sensor has 2 (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 2 sensor circuits and switches to fail-safe mode. In fail-safe mode, the remaining circuit is used to calculate the accelerator pedal opening angle 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:
Step 1-2:
Step 3-5:
Step 1-2:
Step 2(Continued)-4:
INSPECTION PROCEDURE
HINT: Read freeze frame data using the intelligent tester or the OBD II scan tool. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. 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.