Throttle Actuator Control

The Throttle Actuator Control (TAC) controls air flow to the engine. Engine does not use a throttle cable to control engine speed. The throttle body contains a direct current stepper motor that is controlled by the ECM. The ECM is able to control the stepper motor by moving throttle plate in either direction to increase or decrease air flow to engine. A problem in TAC sensor circuit may set a related DTC. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - 3.0L SATURN "L" SERIES article.