
FunctioniNotes/tipsDSwitches the rear window
defroster on/offESets the airflow, rightFSets the temperature, rightSet the temperature to 72 ‡ (22 †).GSets climate control to
automatic, rightActivate climate control using the à rocker
switch. The indicator lamp in the à rocker switch
lights up.Rear control panelHSets the temperature, leftSet the temperature to 72 ‡ (22 †).ISets the air distribution, leftJSets the airflowKOFF Deactivates the rear-
compartment climate control
AUTO Sets the rear-
compartment climate control
to automatic
MAN Sets the rear-
compartment climate control
to manualLSets the air distribution, rightMSets the temperature, rightSet the temperature to 72 ‡ (22 †).Operating the climate control
systems
Switching climate control on/off
Important information
GWarning!
When the climate control system is
deactivated, the outside air supply and
circulation are also deactivated. Only choose
this setting for a short time. Otherwise the
windows could fog up, impairing visibility and
endangering you and others.
i Activate climate control primarily using
the à rocker switch ( Y page 289).
Activating/deactivating the front
climate control using the front control
panelXTurn the key to position 2 in the ignition
lock.XTo switch on: press the ^ rocker
switch up or down.
The indicator lamp in the rocker switch
goes out. The previously selected settings
come into effect again.XTo switch off: press the ^ rocker
switch up or down.
The indicator lamp in the rocker switch
lights up.288Operating the climate control systemsClimate control

Activating/deactivating the rear-
compartment climate control using the
front control panelXTurn the key to position 2 in the ignition
lock.XActivate the Y rear compartment
function via COMAND ( Y page 265).
The rear-compartment climate control can
be controlled via the front control panel
using the Y rear compartment function.XTo switch on: press the ^ rocker
switch up or down.
The indicator lamp in the rocker switch
goes out. The previously selected settings
come into effect again.XTo switch off: press the ^ rocker
switch up or down.
The indicator lamp in the rocker switch
lights up.
Activating/deactivating the rear-
compartment climate control using the
rear control panel
XTurn the key to position 2 in the ignition
lock.XTo activate: press rocker switch
K (Y page 287) up or down and select
AUTO .
or
XPress rocker switch K (Y page 287) up or
down and select MAN.XTo deactivate: press rocker switch
K (Y page 287) up or down and select
OFF .
Activating/deactivating cooling with
air dehumidification
Important information
The cooling with air dehumidification function
is only available when the engine is running.
The air inside the vehicle is cooled and
dehumidified according to the temperature
selected.GWarning
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
Condensation may drip from the underside of
the vehicle when the automatic climate
control is in cooling mode. This is normal and
not a sign that there is a malfunction.
You can activate or deactivate the "cooling
with air dehumidification" function via
COMAND ( Y page 263).
i The cooling with air dehumidification
function uses refrigerant R134a. This
coolant does not contain
chlorofluorocarbons, and therefore does
not damage the ozone layer.
Problems with the "cooling with air
dehumidification" function
If you can no longer switch on the cooling with
air dehumidification function via COMAND,
the cooling with air dehumidification function
is switched off due to a malfunction.
XConsult a qualified specialist workshop.
Setting climate control to automatic
GWarning
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
In automatic mode, the set temperature is
maintained automatically at a constant level.
The system automatically regulates the
temperature of the dispensed air, the airflow
and the air distribution.
Operating the climate control systems289Climate controlZ

This is the quickest way to cool the vehicle
interior when the sliding sunroof and the side
windows are closed.
Defrosting the windows
Windows fogged up on the inside
XActivate the "cooling with air
dehumidification" function via COMAND
( Y page 263).XActivate automatic mode Ã.XIf the windows continue to fog up, activate
the defrosting function ( Y page 292).
i
You should only select this setting until
the windshield is clear again.
Windows fogged up on the outside
XActivate the windshield wipers.XActivate automatic climate control.
i You should only select this setting until
the windshield is clear again.
Rear window defroster
Activating/deactivating
GWarning
Any accumulation of snow and ice should be
removed from the rear window before driving.
Visibility could otherwise be impaired,
endangering you and others.
The rear window heating has a high current
draw. You should therefore switch it off as
soon as the window is clear as it only switches
off automatically after several minutes.
If the battery voltage is too low, the rear
window heating may switch off.
XTurn the SmartKey to position 2 in the
ignition lock.XPress the ¤ rocker switch up or down.
The indicator lamp in the ¤ rocker
switch lights up or goes out.Problems with the rear window heating
The rear window heating has deactivated
itself prematurely or cannot be activated.
XSwitch off any consumers that are not
required, e.g. reading lamps or interior
lighting.
When the battery is sufficiently charged,
the rear window heating 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.
GWarning
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.
XTurn the SmartKey to position 2 in the
ignition lock.XTo activate: press the g rocker switch
up or down.
The indicator lamp in the g rocker
switch lights up.
i Air-recirculation mode is activated
automatically at high outside
temperatures. The indicator lamp in the
g rocker switch is not lit when
automatic air-recirculation mode is
activated.
Outside air is added after about 30
minutes.
Operating the climate control systems293Climate controlZ

remain responsible for the vehicle's speed
and for safe brake operation.
Only use the cruise control if the road, traffic,
and weather conditions make it advisable to
travel at a constant speed.
R The use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow safe
driving at a constant speed.
R The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in wheel
spin and loss of control.
R Deactivate the cruise control when driving
in fog.
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate cruise control?To store the current speed or to call up
the last stored speed
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds and is indicated in the
speedometer by a triangle. The speedometer
dial lights up between the set speed and the
maximum speed.
Storing and maintaining the current
speed
You can store the current speed if you are
driving faster than 20 mph (30 km/h).
XAccelerate the vehicle to the desired
speed.XBriefly press the cruise control lever
up : or down ; to the pressure point.XRemove your foot from the accelerator
pedal.
Cruise control is activated. The vehicle
automatically maintains the stored speed.
i Cruise control may be unable to maintain
the stored speed on uphill gradients. The
stored speed is resumed when the gradient
evens out. Cruise control maintains the
stored speed on downhill gradients by
automatically applying the brakes.
Storing the current speed or calling up
the last stored speed
GWarning
The set speed stored in memory should only
be set again if prevailing road conditions and
legal speed limits permit. Possible
acceleration or deceleration differences
arising from returning to the preset speed
could cause an accident and/or serious injury
to you and others.
XBriefly pull the cruise control lever towards
you ?.XRemove your foot from the accelerator
pedal.
The first time cruise control is activated, it
stores the current speed or regulates the
speed of the vehicle to the previously
stored speed.324Driving systemsDriving and parking

Display messagesPossible causes/consequences and M Solutionsb
Active Headlamps
InoperativeThe active light function is faulty.XVisit a qualified specialist workshop.b
Malfunction See
Oper. ManualThe exterior lighting is faulty.XVisit a qualified specialist workshop.b
AUTO Lamp Function
InoperativeThe light sensor is faulty.XVisit a qualified specialist workshop.
USA only:
XSwitch off the daytime running lamps in the on-board computer
( Y page 377).XSwitch the lights on and off using the light switch.b
Please Switch Off
LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to $ or c .
or
XIf the rear fog lamp is switched on: press the light switch in to
the stop.Adaptive High-beam
Assist
InoperativeAdaptive Highbeam Assist is faulty.XVisit a qualified specialist workshop.
Engine
Display messagesPossible causes/consequences and M Solutions+
Check Coolant
Level See Oper.
ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 450).XIf coolant needs adding more often than usual, have the engine
coolant system checked at a qualified specialist workshop.GWarning
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
Display messages397On-board computer and displaysZ