TAC Motor
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The TAC motor is part of the throttle body and controls the positions of the throttle. The motor is bi-directional and is controlled by the TAC module. The TAC motor increases or decreases the engine RPM.