Circuit Description

The accelerator pedal position (APP) sensors 1 and 2 are located within the accelerator pedal assembly. Each sensor has the following circuits:

• A 5-volt reference circuit
• A low reference circuit
• A signal circuit

This provides the engine control module (ECM) with a signal voltage proportional to accelerator pedal movement. The APP sensors have opposite functionality. The APP sensor 1 signal voltage increases as the pedal is depressed, from approximately 1 volt at rest to above 2.5 volts when fully depressed. The APP sensor 2 signal voltage decreases as the pedal is depressed, from approximately 4 volts at rest to less than 1 volt with the accelerator pedal fully depressed. If the ECM detects that the APP sensor 2 signal voltage is not within the predicted range, this DTC sets.