Throttle Position Sensor & Idle Switch

Throttle Position (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 ECM in an input voltage signal from TP sensor. TP sensor contains a closed throttle position switch and a wide open throttle position switch. Wide open throttle position switch is only used for automatic transmission control. Closed throttle position switch is only used by ECM to open or close EVAP canister purge control valve when TP sensor is malfunctioning.