Hot film mass air flow sensor, function - GF07.07-P-4118-02G
The electronics in the hot film mass air flow sensor controls the temperature of the heating resistor (R H ) by means of a variable voltage so that its temperature is 160 °C above the intake air temperature detected by the temperature resistor (R L ).
The temperature of the heating resistor (R H ) is detected by the sensor resistor (R S ). If a temperature change occurs as a result of an increased or reduced air flow, the electronics adapts the voltage at the heating resistor (R H ) 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.