Throttle Position Sensor

Throttle Position (TP) sensor is a potentiometer connected to the throttle shaft on the throttle body. PCM monitors voltage on TP sensor signal line and calculates throttle position. As throttle valve angle is changed (accelerator pedal moved), TP sensor signal also changes. At closed throttle position, output of the TP sensor is low. As the throttle valve opens, output increases so that at wide open throttle, output voltage should be above 92% (scan tool display). PCM calculates fuel delivery based on throttle valve angle (driver demand). A broken or loose TP sensor may cause intermittent bursts of fuel from an injector and unstable idle because PCM thinks throttle is moving. V6 engines are equipped with 2 TP sensors, while 4 cylinder models have one sensor.