Circuit Description

The throttle position (TP) sensors 1 is used to determine the throttle plate angle by the engine control module (ECM) for various engine management systems. The TP sensor is a potentiometer type sensor with the following three circuits:

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

The ECM provides the TP sensor with a 5-volt reference circuit and a low reference circuit. The TP sensor then provides the PCM with a signal voltage proportional to throttle plate movement. The TP sensor 1 signal voltage at closed throttle is low and increases as the throttle is opened. When the ECM detects the TP sensor 1 voltage is less than 0.195 volts, DTC P0122 sets.