Accelerator Pedal Position Sensor

WARNING: This page is about a different car, the 2003 Saturn LW300 and 2003 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.

The Accelerator Pedal Position (APP) sensor assembly contains 2 individual APP sensors within the assembly. The APP sensors 1 and 2 are potentiometer type sensors each with a 5-volt reference circuit, a low reference circuit and a signal circuit.

The APP sensors are used to determine the accelerator pedal angle. The ECM provides each APP sensor a 5-volt reference circuit and a low reference circuit. The APP sensors provides the ECM with a signal voltage, on the signal circuit that is proportional to the accelerator pedal movement. APP sensor 1 signal voltage is low at the rest position and increases to near the 5-volt reference as the pedal is applied. APP sensor 2 signal is low at rest and also increases as the accelerator pedal is applied. APP sensor 2 increases at a different rate to approximately half the reference voltage. To diagnose APP sensor, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 3.0L SATURN "L" SERIES article.