Accelerator Pedal Position Sensor: Description and Operation
ACCELERATOR PEDAL POSITION (APP) SENSORThe APP sensor is a 3-track potentiometer that is used to calculate driver demand for fuel quantity. The sensor receives a VREF voltage from the PCM and provides a variable voltage signal directly proportional to the accelerator pedal position.
A detected malfunction of the APP sensor illuminates the electronic throttle control (wrench) indicator. A PCM detected fault on one of the 3 sensor signals permits normal engine operation. A fault with 2 sensor signals only allows the engine to operate at idle.