Throttle Position Switch: Description and Operation

Idle (IDL) Switch:

PURPOSE
The Throttle Position (TP) switch, also referred as Idle (IDL) switch inputs to the PCM an idle condition signal to cut off fuel flow during deceleration and control engine idle speed. WOT input is used to modify fuel flow for maximum engine power output. The PCM uses this information to modify air/fuel mixture, idle speed, and fuel pressure.

CONSTRUCTION
The TP switch, integrated into the Throttle Position (TP) sensor contains two sets of contacts detecting when the throttle valve is fully "Closed" or at Wide Open Throttle (WOT).