Humidity Sender For Air Conditioning System G260; Design And Functional Principle; Effects Of Failure - Volkswagen Golf 2014 Service Training

Heating and air conditioning

Humidity sender for air conditioning system G260

Installation location
The humidity sender for the air conditioning system
G260 is only installed with the Climatronic unit. It is
installed in the base of the interior mirror together
with the rain/light sensor.

Design and functional principle

The humidity and the temperature at the windscreen
are measured using a capacitive thin-layer sensor.
The sender functions in a similar manner to a plate
capacitor; measurement of the capacity reveals the
degree of humidity.
Signal utilisation
The sender determines:
- The inside windscreen temperature
- The inside relative humidity
The signals are transmitted to the onboard supply
control unit and are forwarded to the Climatronic
control unit via the convenience CAN bus. This uses
the signals to calculate the inside dew point and the
inside dew point distance.
To reduce the fogging of the windscreen, the
Climatronic ensures that conditions in the passenger
compartment are optimal and initiates the following
measures:
- Compressor on/off
- Defroster flaps open/closed
- Air quantity regulation by changing the fresh air
blower speed
- Evaporator temperature change
- Air recirculation flap in the recirculation/fresh air
position
36
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Effects of failure

Without the sensor's signal, the control unit is no
longer able to calculate the point in time from which
moisture settles on the windows. The automatic
defrost function fails.
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