A mass air flow (MAF) sensor, is one of the key components, of an electronic fuel injection system.

It is located, between the air filter and the intake manifold of the engine.

In most modern cars, they will also have, a intake air temperature (IAT) sensor, built into the (MAF). There are a few types, of air flow sensors, however, modern cars use a (hot-wire) type.

Firstly, the mass air flow (MAF) sensor measures, the amount of air, entering the engine.

A hot-wire mass air flow (MAF) sensor, has a small electrically heated wire (hot wire). A temperature sensor installed close to the hot wire, measures the temperature of the air near the hot wire.

So, when the engine is idling, a small amount of air, flows around the (hot wire). Consequently, it takes a very low electric current, to keep the wire hot. However, when you press the gas, the throttle opens, allowing more air to flow over the (hot wire). As a result, the passing air, cools the wire down.

Rough engine idle, can also be a problem.

So, the more air that flows over the wire, the higher the electrical current must be. Therefore, the electric current is, proportional to the amount of air flow. A small electronic chip, installed inside the mass air flow sensor, translates the electric current into a digital signal. And, then sends it, to the engine computer (PCM). The (PCM) uses the air flow signal, to calculate, how much fuel to inject. So, the goal is, to keep the air fuel ratio, at the optimal level.

In addition, the (PCM) uses, the air flow readings, to determine the shift points of the automatic transmission. Finally, if the air flow sensor, doesn’t work properly, the automatic transmission, might shift differently as well.


Choose Your Mass Air Flow Help Topic Below

Mass Air Flow Sensor – Measures, air volume, density, temperature


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