Idle Up Control Valve: Description and Operation

Throttle Position Sensor - 3.8L:

Purpose and Operation
The Idle Air Control (IAC) valve:

^ is used to control engine idle speed (rpm).

^ is mounted on the throttle body, upper intake manifold or the throttle body adapter (depending upon application).

^ allows air to bypass the throttle plate. The amount of air allowed to bypass is determined by the powertrain control module (PCM) and controlled by a duty cycle signal.