Throttle Position Sensor (TPS)

TPS is mounted on side of throttle body and is connected to throttle shaft. As throttle valve angle changes, resistance of sensor changes. ECM will calculate fuel requirements based upon throttle valve angle (driver demand).

ECM supplies 5-volt reference signal to TPS. Closed throttle condition produces high resistance at sensor, returning low output signal to ECM (about .5 volts). Wide open throttle condition produces low resistance at sensor, returning high output signal to ECM (almost 5 volts).