Throttle Position Sensor: Description and Operation

Throttle Position (TPS) Sensor:

The Throttle Position (TP) sensor, consists of an idle switch and potentiometer. Mounted on the throttle body, the TP sensor contains a pivot arm that moves along a curved resistor, producing signals for both idle and a wide range of throttle plate angles. The Engine Control Assembly (ECA) uses this information to modify air/fuel mixture, idle speed, injector timing, ignition timing, fuel pressure, A/C cutoff, and purge flow.

Throttle Position (TP) Switch:

The Throttle Position (TP) switch, also referred as Idle (IDL) switch is mounted on the throttle body. The TP switch contains two sets of contacts detecting when the throttle valve is fully closed or at wide open throttle. The TP switch inputs to the Electronic Control Assembly (ECA) an idle condition signal to cut off fuel flow during deceleration and control engine idle speed. Wide open throttle input is used to modify fuel flow for maximum engine power output. The ECA uses this information to modify air/fuel mixture, idle speed, injector timing, ignition timing, fuel pressure and purge flow.