Throttle Body Assembly

Fig 1: View Of Intake Air Temperature (IAT) Sensor 2

Courtesy of GENERAL MOTORS CORP.

Callout	Component Name
1	Positive Crankcase Ventilation (PCV) Hose
2	Throttle Actuator Control (TAC) Module
3	Throttle Body
4	Engine Coolant Hoses
5	Intake Air Temperature (IAT) Sensor 2
6	Manifold Absolute Pressure (MAP) Sensor

The throttle body contains a throttle valve that controls the amount of air entering the engine. The throttle valve is opened and closed by the throttle actuator control (TAC) motor. The TAC motor is an integral part of the TAC module assembly (2) mounted on the side of the throttle body. The TAC motor is controlled by commands from the powertrain control module (PCM), passed to the module circuitry through a dedicated serial data line. The TAC module also contains two throttle position (TP) sensors, TP sensor 1 and TP sensor 2. For detailed information on the operation of the TAC system refer to Throttle Actuator Control (TAC) System Description .

In order to prevent cold weather icing and stabilize cold weather performance, the throttle body is warmed by engine coolant (4). The manifold absolute pressure (MAP) sensor (6) is located on top of throttle body.