Mass Airflow (MAF) Sensor

MAF sensor is mounted rigidly to air cleaner housing and is connected by flexible hose to plenum chamber inlet. MAF sensor is a hot wire anemometer which uses 2 wires. A sensing wire which is heated using battery voltage and a compensating wire which is not heated. Intake air passing through MAF sensor causes heated wire temperature to change. As heated wire temperature changes, resistance also changes. ECM measures changes in heated wire resistance and calculates amount of air flowing into engine.

As a default strategy for MAF sensor ECM will calculate a MAF value based on throttle position, engine speed and intake air temperature. A MAF sensor failure will result in hard engine starts, engine may not idle, poor throttle response and driveability, incorrect emissions, and/or a high long term fuel correction. A fault is indicated by illumination of the MIL.