One of the sensors that you rely on to ensure your car is working correctly is the mass air flow (MAF) sensor. This little component plays a big role in whether your vehicle performs the way it should.

The mass air flow sensor is located on the throttle body of fuel injected engines. They are seen on multiport fuel injectors, and come in two different designs. Both designs do the same job, but with a unique method. Those two designs are the hot wire and hot film. Hot wire sensors feature a platinum wire as the sensing element, while hot film uses a nickel foil grid to do the job.

How mass air flow sensors work

The sensing element, whether it’s a hot wire or hot film, stays hotter than air that comes into the fuel injector by being electrically heated. The hot film MAF is set at 75°C hotter than incoming air, while the hot wire is at 100°C above. The air cools the element as it moves past. More current is needed to heat the element, which varies by the amount of air coming in.

The sensor measures the amount of air that comes in and relays that information to the computer. This allows the air/fuel mixture to maintain the correct ratio for optimal performance.

This sensor has an important role in fuel injection systems and may need to be cleaned to keep it in optimal working order. The next time you notice how smoothly your car runs, remember that the MAF sensor is one part that provides this condition.

This article originally appeared on YourMechanic.com as What Does the Mass Airflow Sensor Do? and was authored by Joyce Morse.


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