What is idle air controller on Toyota Sienna 2001?

The idle air control (IAC) valve on a 2001 Toyota Sienna is a component that regulates the engine's idle speed by controlling the amount of air that bypasses the throttle plate. It adjusts the air flow based on engine demands, helping to maintain a stable idle under varying conditions, such as when the engine is cold or when accessories are in use. If the IAC valve malfunctions, it can lead to rough idling, stalling, or difficulty starting the engine. Regular maintenance and cleaning can help ensure its proper function.