Engine Control Module
WARNING: This page is about a different car, the 2005 Saturn L300. However, it is still accessible from the selected car via links, so may be relevant.
The TAC module in this system is integrated into the ECM. The TAC achieves throttle positioning by providing a pulse width modulated voltage to the TAC motor after determining the drivers intent and then calculating the appropriate throttle response. The TAC module is not serviced and is to be replaced with the ECM.