, an automatic idle speed motor, also known as an idle air control motor (IAC motor) or idle air control valve (IAC valve), is a vital component in modern vehicles. It regulates the engine's idle speed by controlling the airflow when the vehicle is not moving and the throttle is closed. The idle speed motor is electronically controlled by the Engine Control Unit (ECU) and can be a stepper motor or solenoid. It compensates for changes in engine load, provides additional air or fuel during cold starts, and ensures a stable and smooth idle.