Circuit Description

The engine control module (ECM) controls the throttle valve by applying a varying voltage to the throttle actuator control (TAC) motor. The ECM monitors the actual throttle valve position using throttle position (TP) sensor 1 and 2. The ECM amplifies the TP sensor 1 signal in order to obtain a more accurate signal. The ECM monitors the TP sensor 1 amplification output whenever the ignition is ON and a closed throttle test is performed. If the ECM detects the internal TP sensor 1 amplification output does not correlate with the TP sensor 1 signal voltage, this DTC sets.