Accelerator Pedal Position Sensor: Description and Operation
ENGINE CONTROL COMPONENTSAccelerator Pedal Position (APP) Sensor
The APP sensor is a 3-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 3 APP sensor inputs to calculate the desired fuel quantity, injection timing, and the correct injection control 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 3 sensor signals. If the PCM detects a concern on two of the 3 sensor signals, the PCM only allows the engine to operate at idle.