Accelerator Pedal Position (APP) Sensor
The APP sensor is a 2-track potentiometer that is used to calculate driver demand for power based on the rotation angle of the accelerator pedal. The sensor receives a reference voltage from the powertrain control module (PCM) and provides a variable voltage signal directly proportional to the accelerator pedal position. The PCM uses the 2 APP sensor inputs to calculate the desired fuel quantity, injection timing, and the correct fuel pressure. A concern with the APP sensor illuminates the powertrain malfunction indicator (wrench). Normal engine operation is permitted if the PCM detects a concern on one of the 2 sensor signals. If the PCM detects a concern on both of the sensor signals, the PCM only allows the engine to operate at idle.