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Meter of air (MAF)

Meter of air provides the most direct method to measure the load of the engine, as it measures the amount of air entering the engine. Feed air enters the engine through the meter with a hot and cold film elements forming part of a bridge circuit. The current passing through the heated film member maintains its constant temperature at a constant level which is higher than the temperature of air entering the engine. Air mass is determined by the strength of current required to maintain the temperature of the film element. The greater the air flow, and naturally cooling thereof, the greater the value of the signal applied to the ECM.