Circuit Description

The accelerator pedal position (APP) sensor is made up of 2 sensors that are housed inside one assembly. The engine control module (ECM) supplies a separate 5-volt reference and low reference circuit for each of the sensors. The 5-volt reference for the APP sensor 2 is supplied from the same source in the ECM as the 5-volt reference for the throttle position sensors. The 5-volt reference voltage for all of the sensors is supplied on separate ECM terminals, but the terminals are connected internally to a voltage supply. The APP sensor 2 sends a signal indicating the accelerator pedal position and the ECM actuates the throttle plates based on this information. The APP sensor 2 signal voltage increases from about 0.2 volts at rest to about 1.8 volts when fully depressed. If the ECM detects that the signal voltage is excessively high, DTC P2128 sets.