Circuit/System Description
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The engine control module (ECM) is the control center for the throttle actuator control (TAC) system. The ECM determines the drivers intent and then calculates the appropriate throttle response. The ECM achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor through the motor control 1 circuit and the motor control 2 circuit.
Two processors are used to monitor the TAC system data. Both processors are located within the ECM. Both processors monitor and share data to verify that the indicated throttle position is correct.