Throttle Position (TP) Sensor

TP sensor is connected to throttle valve shaft. It informs ECM of power requested by driver (throttle opening). Idle and full throttle switches are not used in potentiometer. Idle speed and full throttle applications are recognized by ECM from voltage output of potentiometer. See Figure .

TP sensor signals are used for idle speed stabilization, idle air volume control, fuel after-run shutoff, and full throttle enrichment. ECM uses mass airflow sensor signal and engine RPM signals as substitute values if TP sensor fails.