Throttle Actuator Control Module
WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.
A malfunction in Throttle Actuator Control TAC) module can set a DTC. For testing procedure, perform related diagnostic test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 5.7L CORVETTE article.