check engine AUDI A4 1995 B5 / 1.G AFC Engine Mass Air Flow Sensors Checking Workshop Manual

24-84

Checking function

- Slide back protective boot from back of MAF
sensor connector (leaving it connected).

Note:
The connector pin numbers are marked on the
back of the connector itself.

- Switch multimeter (Fluke 83 or equivalent) to
measure voltage and connect between terminal
2 (GND) and terminal 1 (B+) using jumper wires
from connector test kit VW 1594.

- Switch ignition ON.

Specified value: 0.3 to 1.1 volts

- Start engine and let idle.

- Switch off all electrical consumers (engine
coolant fan should not run during measurement).

Continuously vary engine speed between idle
and 4000 RPM.


Specified value: 1.5 volts minimum to 3.4 volts
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max. depending on engine speed (RPM)
If the specified value is not obtained:

- Replace Mass Air Flow (MAF) sensor.
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