Throttle Body: Description and Operation

Throttle Body Assembly:

DESCRIPTION
The throttle body assembly is a downdraft design. The throttle body is mounted on the intake manifold plenum. The VCM uses the throttle body to control air flow into the engine, thereby, controlling engine output. The throttle body also provides the location for mounting the Throttle Position (TP) sensor. The throttle body also senses changes in the engine vacuum due to the throttle valve position. The vacuum ports are located at, above, or below the throttle valve in order to generate the vacuum signals needed by various components.


OPERATION
The throttle valve within the throttle body is opened by the driver through the [1][2]accelerator controls. During engine idle, the throttle valve is almost closed, and the Idle Air Control (IAC) valve handles the air flow control.