Throttle Position Sensor
The Throttle Position (TP) sensor is used by the PCM to determine the throttle plate angle for various engine management systems. TP sensor is mounted on throttle body assembly. See Fig 1 . The TP sensor is a potentiometer type sensor with a 5-volt reference circuit, a low reference circuit and a sensor signal circuit. PCM provides the TP sensor with 5 volts on the 5-volt reference circuit and a ground on the low reference circuit. Rotation of the TP sensor rotor from the closed throttle position to Wide Open Throttle (WOT) position provides the PCM with a signal voltage from less than one volt to greater than 4 volts through the TP sensor signal circuit. When TP sensor signal voltage is not within the predicted range, a DTC sets. To diagnose, see SELF-DIAGNOSTICS - 4.3L SIERRA & SILVERADO article.