GF07.07-P-6000SM | Component description for a hot film MAF sensor | 22.3.04 |
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B2/5 Hot film mass air flow sensor (HFM-SFI)
Task The hot film MAF sensor detects the suctioned in air mass and the integral temperature sensor for the intake air temperature. |
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P07.07-2051-11 |
Design
9/3 Flow rectifier 9/4 Housing 9/5 Electrical connection: Pin 1: Reference mass Pin 2 : Circuit 87 Pin 3: HFM sequential multiport fuel injection/ignition system signal (air mass) Pin 4: Power ground for HFM sequential multiport fuel injection/ignition system Pin 5: Not assigned 9/6 Adhesive molding 9/8 Hybrid printed circuit board 9/9 Cover B2/5 Hot film mass air flow sensor |
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P07.07-2028-06 |
Schematic representation
R1, R2 Fixed resistor RH Heating resistor RL Temperature resistor rs Sensor resistor |
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P07.07-2009-05 |
Function
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 thermistor is measured over the sensor resistance (RS). |
If a temperature change occurs as a result of increased or reduced air flow, the electronic control corrects the voltage at the heating resistor until the temperature difference (160°C) is reached again. This control voltage is used by the ME control unit (N3/10) as a measure for the metered air mass. The intake air temperature is detected by the integral NTC resistor and transmitted to the ME control unit as a voltage signal. |