Mercedes-Benz M-Class 2012 Owners Manual - Manual (Page 135)

Problems with the rear window
defroster
The rear window defroster has deactivated
itself prematurely or cannot be activated.
X Switch off any consumers that are not
required, e.g. reading lamps or interior
lighting.
When the battery is sufficiently charged,
the rear window defroster is activated
again automatically.
Activating/deactivating air-
recirculation mode
You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle
from outside. The air already inside the
vehicle will then be recirculated.
The operation of air-recirculation mode is the
same for all control panels.
G WARNING
Fogged windows impair visibility,
endangering you and others. If the windows
begin to fog on the inside, switching off the
air recirculation mode immediately should
clear interior window fogging. If interior
window fogging persists, make sure the air
conditioning is activated, or press the ¬
button.
X
Turn the SmartKey to position 2 in the
ignition lock.
X To activate: press the d button.
The indicator lamp in the d button lights
up.
i In the event of high pollution levels 13 or at
high outside temperatures, air-
recirculation mode is automatically
activated. When air-recirculation mode is
activated automatically, the indicator lamp
in the d button is not lit.
Outside air is added after about 30
minutes.
X To switch off: press the d button.
The indicator lamp in the d button goes
out.
i Air-recirculation mode deactivates
automatically:
R after approximately five minutes if
outside temperatures are less than about
41 ‡ (5 †)
R after approximately five minutes if
cooling with air dehumidification is
deactivated
R after approximately 30 minutes if outside
temperatures are over about
41 ‡ (5 †)
R if you press the ¿/Á button and
switch on cooling with air
dehumidification
Activating/deactivating the residual
heat function
The residual heat function is only available in
Canada
It is possible to make use of the residual heat
of the engine to continue heating the
stationary vehicle for up to 30 minutes after
the engine has been switched off. The heating
time depends on the temperature that has
been set.
i The blower will run at a low speed
regardless of the airflow setting.
i If you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.
X Turn the SmartKey to position 0 in the
ignition lock or remove it.
X
To activate: press the М/Б button.
The indicator lamp in the М/Б
button lights up.
13 Automatic climate control only.
Operating the climate control system
133
Climate
control
Z