115 Mass Air Flow Sensor - Above Limit: Function

The mass air flow sensor is installed between the air cleaner and the throttle valve, and measures the mass air flow taken in by the engine. An electrically heated platinum resistance film is cooled by the air flow. A control circuit corrects the heating current in such a way that the temperature of the resistance film rises constantly in relation to the intake air temperature. The heating current is then a means of measuring the mass air flow. With this method of measurement, the air density is also taken into consideration, as it helps to determine the amount of heat emitted from the heated body into the air. A temperature sensor is integrated for measuring the intake air temperature.