Volkswagen 1.9 tdi, Owner'S Manual, Page: 40 / 67

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Mass Air Flow Sensor G70
The Mass Air Flow Sensor G70 with reverse
flow recognition is located in the intake pipe.
It determines the intake air mass.
The opening and closing actions of the
valve produce reverse flows in the induced
air mass in the intake pipe.
The Mass Air Flow Sensor G70
recognizes and makes allowance for the
returning air mass in the signal it sends
to the Diesel Direct Fuel Injection Engine
Control Module J248.
The air mass is accurately measured.
Signal application
The Diesel Direct Fuel Injection Engine
Control Module J248 uses the measured
values from the Mass Air Flow Sensor G70
to calculate the injection quantity and the
exhaust gas recirculation rate.
Effects of signal failure
If the signal from the Mass Air Flow Sensor
G70 fails, the Diesel Direct Fuel Injection
Engine Control Module J248 uses a fixed
substitute value.
Engine Management
SSP209/044