Throttle Position (TP) Sensor & Idle Switch

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

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