Air Flow Meter/Sensor: Description and Operation

Mass Air Flow Sensor:

The Mass Air Flow (MAF) sensor measures the flow of air which passes through it in a given time. It does this by measuring the electrical power required to maintain the sensing element at a specific temperature above the ambient temperature. As the air enters the sample tube it passes over and cools the sensing element, which then requires additional current to maintain the prescribed uniform temperature differential. The PCM measures the current required to maintain this temperature differential, calculates the quantity (mass/unit time) of the incoming air, and uses this information to determine how much fuel is needed. Once this is determined, the PCM calculates the injector pulse width required to deliver the correct amount of fuel.