Your engine’s primary air intake valve connects to the IAC or Idle Air Control Solenoid Valve. That valve is what makes necessary adjustments to airflow to the engine and maintains a smooth idle. The IAC lets in air to keep the engine from choking when the throttle plate is closed by taking your foot off the gas. If the Idle Air Control (IAC) is malfunctioning, it is typically noticeable to the driver.
Common Warning Signs of IAC problems:
- Vehicle stalls when idling
- Irregular or high idle speeds
- Check engine light comes on
- Vehicle will not start or stalls immediately after starting