What is the function of throttle body on 2003 ford expedition?

The throttle body on a 2003 Ford Expedition, like on most vehicles, controls the amount of air that flows into the engine. It's essentially a valve that regulates the airflow based on the driver's input (accelerator pedal). A sensor within the throttle body communicates the position of the throttle plate to the engine's computer (Powertrain Control Module or PCM), which then adjusts fuel delivery accordingly to maintain the correct air/fuel mixture for optimal combustion.