Hot Film Air Mass (Hfm) Sensor - SSANGYONG Rexton Y200 Manual

1F2-50 M161 ENGINE CONTROLS
1 Housing
2 Protector Net
3 Electronic Housing
The Hot Film Air Mass (HFM) sensor with recognition of flow direction related to pulsating flow is designed for
recording load on Engine Control Module (ECM) by measuring the output voltage proportional to the reference
voltage of the ECM.
Mass Air Flow Sensor
Mass Air Flow (MAF) is a thermal flow meter whose sensor element with its temperature sensors and heating area
is exposed to the MAF to be measured. A heating area located in the center of a thin membraneis controlled to an
over temperature by a heating resistor and a temperature sensor of this membrane. And the value of over-
temperature depends on the temperature of the in-flowing air.
Two temperature sensors on upstream and downstream of the heating area show the same temperature without
incoming flow. With incoming flow, upstream part is cooled down but downstream temperature retains its temperature
more or less due to the air heated up in the heating area. This temperature difference in quantity and direction
depends on the direction of the incoming flow.
ECM modulates the flow of heating current to maintain the temperature differential between the heated film and
the intake air at a constant level. The amount of heating current required to maintain the temperature thus provides
an index for the MAF. This concept automatically compensates for variations in air density, as this is one of the
factors that determines the amount of warmth that the surrounding air absorbs from the heated element. MAF
sensor is located between the air filter and the throttle valve.

HOT FILM AIR MASS (HFM) SENSOR

4 Connector
5 Hot Film Air Mass Sensor
6 Measuring Port
YAD1F430
SSANGYONG Y200