Air Flow Meter/Sensor: Description and Operation

Mass Airflow Sensor

Description
This is a 'hot film' MAF sensor and it is located between the air filter/engine cover and the throttle body.

The MAF is determined by the cooling effect the flow of intake air has over a "hot film" element contained within the sensor: The higher the air flow the greater the cooling effect and hence the lower the electrical resistance of the "hot film" element.

A fault is detected if the MAF signal exceeds the maximum or minimum threshold or the difference between the calculated load and the actual MAF signal is too great.