Heating, Ventilation and Air conditioning 184
Switching the Climatronic temperature measuring unit
Press and hold the   and   buttons to switch the temperature display 
between Celsius and Fahrenheit.
Heat
The maximum heat output required to defrost windows quickly is only avail-
able when the engine has reached its normal running temperature.
The air conditioning system does not switch on
If the air conditioning system cannot be switched on, this may be caused by 
the following:
 xThe engine is not running.
 xThe fan is switched off.
 xThe climate control fuse has blown.
 xThe outside temperature is lower than approximately +3 °C (+38 °F).
 xThe climate control system compressor has been temporarily switched off 
because the engine coolant temperature is too high.
 xAnother fault in the vehicle. Have the climate control system checked by 
a qualified workshop.
Things to note
If the humidity and temperature outside the vehicle are high, condensation 
can drip off the evaporator in the cooling system and form a pool underneath 
the vehicle. This is normal and does not indicate a leak!
Dust and pollen filter
The dust and pollen filter with its activated charcoal cartridge serves as a 
barrier against impurities in the ambient air.
For the climate control system to work with maximum efficiency, the dust and 
pollen filter must be replaced at the intervals specified in the Maintenance 
Programme.If the filter loses efficiency prematurely due to use in areas with very high 
levels of air pollution, the filter must be changed more frequently than stated 
in the Service Schedule.
Note
The climate control system must left running for a few minutes to reach the 
set temperature in the vehicle interior.
Note
After starting it, any residual humidity in the climate control system could 
mist over the windscreen.
Note
The air from the vents flows through the passenger compartment and out 
through the outlets below the rear window. Do not cover these outlets with 
items of clothing or other objects.
ACAUTO