Circuit Description
WARNING: This page is about a different car, the 2004 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
The throttle actuator control (TAC) system uses vehicle electronics and components to calculate and control the position of the throttle plate. In order to decrease idle speed the TAC system closes the throttle plate, reducing air flow into the engine. In order to increase idle speed the TAC system opens the throttle plate allowing more air flow into the engine. If the actual idle RPM does not match the desired idle RPM within a calibrated time, this code sets.