Accelerator Pedal Position (APP) Sensor

The accelerator pedal contains 2 individual APP sensors within the assembly. The Accelerator Pedal Position (APP) sensors 1 and 2 are potentiometer type sensors each with 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 control module (ECM) provides each APP sensor 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 less than 1 volt and increases to above 4 volts as the pedal is actuated. The APP sensor 2 signal voltage at rest position is near 0.5 volt and increases to more than 2 volts as the pedal is actuated.