LW2 V6-3.0L VIN R (2000)
Accelerator Pedal Position Sensor: Description and Operation
The Accelerator Pedal Position (APP) sensor is a part of the new electronic throttle control system on this vehicle. There is no longer a cable linking the
accelerator pedal to the throttle butterfly. Instead, the pedal position sensor relays the desired throttle position to the Engine Control Module (ECM).
The ECM then commands the throttle motor to move the butterfly to the desired position.
The APP system employs two independent potentiometers. One is redundant, and exists to diagnose the first, and also to serve as a temporary back-up in
case the first potentiometer fails. When the accelerator pedal is at its normal resting state, both of the potentiometers read a low value. Under
Wide-open-throttle (WOT), both of the potentiometers read a high value. It is important to note that the voltage on the signal wire of potentiometer 2
should always read half the value of the voltage on the signal wire of potentiometer 1.
