Electronic Throttle Actuator: Description and Operation

ENGINE CONTROL COMPONENTS

Throttle Actuator Control (TAC) Motor
The TAC motor is a DC motor controlled by the PCM (requires two wires). The motor housing is integrated into the main housing. An internal spring is used to return the throttle plate to a default position. The default position is typically a throttle angle of 7 to 8 degrees from the hard stop angle. The closed throttle plate hard stop is used to prevent the throttle from binding in the bore. This hard stop setting is not adjustable and is set to result in less airflow than the minimum engine airflow required at idle. For additional information, refer to the Torque-Based Electronic Throttle Control (ETC).