Circuit Description

The throttle position (TP) sensor is used by the engine control module (ECM) to determine the throttle plate angle for various engine management systems. The TP sensor is a potentiometer type sensor with three circuits:

• A 5-volt reference circuit
• A low reference circuit
• A TP sensor signal circuit

The ECM 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 the wide open throttle (WOT) position provides the ECM with a signal voltage from below 1 volt to greater than 4 volts through the TP sensor signal circuit. If the ECM detects an intermittent excessively high signal voltage, DTC P1121 sets.