GF07.07-P-4118-02G

Hot film mass air flow sensor, function

9/1 Hot film sensor 9/5 Electronics housing RH Heating resistor RL Temperature resistance RS Sensor resistance
		P07.13-0439-76

The elecronics in the hot film mass air flow sensor controls the temperature of the heating resistor (RH) by means of a variable voltage so that its temperature is 160 °C above the intake air temperature detected by the temperature resistor (RL). The temperature of the heating resistor (RH) is detected by the sensor resistor (RS). If a temperature change occurs as a result of an increased or reduced air flow, the electronics adapts the voltage at the heating resistor (RH) until the temperature difference is again achieved.

This control voltage is used by the engine control unit as a measure for the metered air mass. The intake air temperature is detected by an additional NTC resistor.