Mass air flow sensors (MAF Sensors) measure the air flow into the engine to calculate the engine load by ECU computer. Mass Airflow Sensor (MAF) is one of the components of an electronic fuel injection system. Mass air flow sensor helps to measure engine load so that the engine ECU computer may alter spark timing and the air-fuel mixture in the fuel injection system to improve vehicle performance (fuel economy, acceleration) and emissions. Mass air flow meters measure the air flow by the output voltage signal of MAF sensor. Airflow sensors are also used for hot-airflow and gas flow measurements.

Mass air flow sensors usually mounted ahead of the throttle body on multiport fuel injected engines, the MAF sensor monitors the volume of air entering the engine. The sensor uses either a hot wire or heated filament to measure both airflow and air density.

Bad or contaminated Mass Air Flow sensor can possibly cause a wide range of various vehicle driveability problems such as stalling, especially when the engine is cold, misfiring, poor acceleration, etc. In addition, a problem with the Mass Air Flow sensor often causes the “check engine” or “service engine soon” light in the vehicle instrument panel to illuminate.

The sensing element in Mass Airflow sensors can be easily contaminated causing hard starting, rough idle, hesitation and stalling problems. Cleaning a dirty MAF sensor with electronics cleaner can often restore normal sensor operation and save the cost of having to replace the sensor (which is very expensive!).

Types of Automotive Mass Air Flow Sensors

  • Vane Airflow sensors – VAF sensors
  • Hot-wire Mass Air Flow Sensors
  • Cold-wire Mass Air Flow Sensors
  • Karman vortex Mass Air Flow sensors