Low Idle Airflow Test: Notes
WARNING: This page does not describe the selected car, but rather 31 other vehicles, including the 2006 Mercury Mountaineer, 2006 Mercury Monterey, 2006 Mercury Montego, 2006 Mercury Milan, and 2006 Mercury Mariner. However, it is still accessible from the selected car via links, so may be relevant.
When the cold start emission reduction monitor is enabled, the idle air control system requests a higher RPM, elevating engine airflow. While this cold start emission reduction elevated airflow is requested, the low airflow test compares the measured idle airflow from the mass air flow (MAF) sensor to the commanded idle air control strategy. For the purpose of detecting low airflow failures, the low airflow test uses the measured airflow and the commanded airflow to create a low airflow index.