Circuit Description

The accelerator pedal position (APP) sensor 1 and sensor 2 are located within the accelerator pedal assembly. Each sensor has the following circuits:

• A 5-volt reference
• A low reference
• A signal

This provides the engine control module (ECM) with a signal voltage proportional to accelerator pedal movement. The APP sensor 1 signal voltage at rest position is near the low reference and increases as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near the 5-volt reference and decreases as the pedal is actuated. If the ECM detects the APP sensor 1 signal voltage is not within the predicted range, DTC P2123 sets.