Mercedes-Benz C-Class Operator's Manual page 139

Problems with the rear window defroster
Problem
The rear window
defroster has deactiva-
ted prematurely or can-
not be activated.
Switching air-recirculation mode
on/off
General notes
You can also temporarily deactivate the flow of
fresh air manually if unpleasant odors are enter-
ing the vehicle from outside. The air already
inside the vehicle will then be recirculated.
If you switch on air-recirculation mode, the win-
dows can fog up more quickly, in particular at
low temperatures. Only use air-recirculation
mode briefly to prevent the windows from fog-
ging up.
Switching on/off
Turn the SmartKey to position 2 in the ignition
X
lock ( page 146).
Y
To activate: press the g rocker switch up
X
or down.
The indicator lamp above the g rocker
switch lights up.
Air-recirculation mode switches on automati-
cally:
at high outside temperatures
R
at high levels of pollution (3-zone automatic
R
climate control only)
in a tunnel (vehicles with a navigation system
R
only)
The indicator lamp above the g rocker
switch is not lit when automatic air-recirculation
mode is activated. Outside air is added after
about 30 minutes.
To deactivate: press the g rocker switch
X
up or down.
The indicator lamp above the g rocker
switch goes out.
Operating the climate control systems
Possible causes/consequences and M Solutions
The battery has not been sufficiently charged.
Switch off any consumers that are not required, e.g. reading lamps,
X
interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window defroster
can be activated again.
Air-recirculation mode deactivates automati-
cally:
after approximately five minutes at outside
R
temperatures below approximately 41 ‡
(5 †)
after approximately five minutes if cooling
R
with air dehumidification is deactivated
after approximately 30 minutes at outside
R
temperatures above approximately 41 ‡
(5 †) if the "Cooling with air dehumidifica-
tion" function is activated
Switching the residual heat on or off
General notes
The residual heat function is only available with
3-zone automatic climate control on vehicles for
Canada.
Once the engine is switched off, it is possible to
make use of the residual heat of the engine to
continue heating or ventilating the front com-
partment of the vehicle for approximately
30 minutes. The heating or ventilation time
depends on the interior temperature that has
been set.
Switching on/off
Turn the SmartKey to position 0 in the ignition
X
lock or remove it (
Y
To switch on: press the ! rocker switch
X
up or down.
The indicator lamp above the ! rocker
switch lights up.
The blower will run at a low speed regardless of
the airflow setting.
If you activate the residual heat function at high
temperatures, only the ventilation will be acti-
vated. The blower runs at medium speed.
page 146).
137