Throttle Actuator Control Module
WARNING: This page is about a different car, the 2003 Chevrolet SSR. However, it is still accessible from the selected car via links, so may be relevant.
The throttle actuator control (TAC) module is the control center for the throttle actuator control system. The TAC system is self-diagnosing and provides diagnostic information to the powertrain control module (PCM) through a dedicated serial data line. The TAC achieves throttle positioning by providing a pulse width modulated voltage to the TAC, as directed by the PCM.