Accelerator Pedal Position Sensor: Description and Operation

ACCELERATOR PEDAL POSITION (APP) SENSOR

The accelerator pedal contains 2 individual sensors within the assembly. The accelerator pedal position (APP) sensors 1 and 2 are potentiometer type sensors, each with the following 3 circuits:
- A 5-Volt reference circuit
- A low reference circuit
- A signal circuit

The APP sensors are used to determine the pedal angle. The engine controls module (ECM) provides each APP sensor with a 5-Volt reference circuit and a low reference circuit. The APP sensors provide the ECM with signal voltage proportional to the pedal movement. The APP sensor 1 signal voltage at rest position is near low reference and increases as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near low reference and increases as the pedal is actuated.