Throttle Position (TP) Sensor & Idle Switch

TP sensor is attached to throttle body housing and is actuated by movement of accelerator pedal. TP sensor has a potentiometer which varies output voltage in response to changes in throttle position. This information is relayed to PCM in form of an input voltage signal on 3-terminal TP sensor harness. TP sensor also has ability to inform PCM of rate of changes taking place in throttle plate movement.

An idle switch is an integral part of TP sensor. Switch is closed at idle and open during all other conditions. Switch is used to inform PCM when throttle is closed for fuel-cut on deceleration. Switch also has a full throttle position used only on vehicles equipped with an automatic transmission.