Throttle Body: Description and Operation

Throttle Body:

The throttle body has a throttle valve to control the amount of air entering the engine. The throttle position (TP) sensor and idle air control (IAC) valve are also mounted on the throttle body.

On vehicles equipped with California Emissions, there is also a throttle opener located on the throttle body. The throttle opener is used to increase idle speed during engine start-up conditions.

The throttle body contains vacuum ports located at, above or below the throttle valve. These ports provide the vacuum source needed by various components.