The APP (Accelerator Position Sensor) is usually attached to the throttle body, and its function is to monitor the movement of the accelerator pedal. This sensor converts pedal movement to an electronic input signal that is sent to the PCM (Powertrain Control Module), which uses it to open or close the throttle body.
When the accelerator pedal is depressed, the pressure spins the throttle plate within the throttle body, thus opening an internal passage of the unit, which allows airflow to pass through. As air moves through the throttle passage into the intake manifold, the MAF sensor activates and signals the ECU to force fuel into the fluid injection system
The ABS control module constantly monitors the APP sensor to ensure good system performance. If electrical values outside the manufacturer’s expectations are discovered on this sensor, the diagnostic code C1750 OBDII will be set.