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Problems with the rear window defroster
ProblemPossible causes/consequences andMSolutions
The rear window
defroster has deactiva-
ted prematurely or can-
not be activated.The on-board voltage is too low because too many electrical con-
sumers are switched on.
XSwitch off any consumers that are not required, e.g. reading
lamps, interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window
defroster can be activated again.
Switching air-recirculation mode
on/off
General notes
If you switch on air-recirculation mode, the
windows can fog up more quickly, in particu-
lar at low temperatures. Only use air-recircu-
lation mode briefly to prevent the windows
from fogging up.
Activating or deactivating
XTurn the SmartKey to position 2in the igni-
tion lock (
Ypage 151).
XTo activate: press thegbutton.
The indicator lamp in the gbutton lights
up.
iAir-recirculation mode is automatically
activated at high levels of pollution or at
high outside temperatures. When air-recir-
culation mode is activated automatically,
the indicator lamp in the gbutton is not lit. Outside air is added after about
30 minutes.
XTo deactivate:
press thegbutton.
The indicator lamp in the gbutton goes
out.
iAir-recirculation mode deactivates auto-
matically:
Rafter approximately five minutes at out-
side temperatures below approximately
41 ‡ (5 †)
Rafter approximately five minutes if cool-
ing with air dehumidification is deactiva-
ted
Rafter approximately 30 minutes at out-
side temperatures above approximately
41 ‡ (5 †) if the "Cooling with air dehu-
midification" function is activated
Switching the residual heat on or off
General notes
146Operating the climate control systems
Climate control
Page 149 of 614

The residual heat function is only available on
vehicles for Canada.
It is possible to make use of the residual heat
of the engine to continue heating the station-
ary vehicle for up to 30 minutesafter the
engine has been switched off. The heating
time depends on the set interior temperature.
Activating or deactivating
XTurn the SmartKey to position0in the igni-
tion lock or remove it (
Ypage 151).
XTo activate: press theÌbutton.
The indicator lamp in the Ìbutton lights
up.
iThe blower will run at a low speed regard-
less of the airflow setting.
iIf you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.
XTo deactivate: press theÌbutton.
The indicator lamp in the Ìbutton goes
out.
Residual heat is deactivated automatically:
Rafter approximately 30 minutes
Rwhen the ignition is switched on
Rif the battery voltage drops
Setting the air vents
Important safety notes
GWARNING
Very hot or very cold air can flow from the air
vents. This could result in burns or frostbite in
the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior.
GWARNING
When AIRSCARF is switched on, very hot air
can flow from the vents in the head restraints. This could result in burns in the immediate
vicinity of the air vents. There is a risk of injury.
Reduce the heater output before it becomes
too hot.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
Rkeep the air inlet grille on the hood and in
the engine compartment on the front-
passenger side free of blockages, such as
ice, snow or leaves.
Rnever cover the air vents or air intake grilles
in the vehicle interior.
iYou can move the adjusters for the air
vents vertically or horizontally to set the
direction of the airflow.
iFor optimal climate control in the vehicle,
open the air vents completely and set the
adjusters to the central position.
Setting the center air vents
XTo open the center air vents: turn the
adjuster in one of center air vents :coun-
ter-clockwise.
XTo close the center air vents: turn the
adjuster in one of center air vents :clock-
wise until it engages.
Setting the air vents147
Climate control
Z
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stop phase. When you depress the accel-
erator pedal, the engine starts automati-
cally and the braking effect of the HOLD
function is deactivated.
Automatic engine start
The engine starts automatically if:
Ryou switch off the ECO start/stop function
by pressing the ECO button
Rin transmission position Dor Nthe brake
pedal is released and the HOLD function is
not active
Ryou depress the accelerator pedal
Ryou engage reverse gear R.
Ryou move the transmission out of position
P
Ryou switch to drive program S,S+ orM
(Mercedes-AMG vehicles)
Ryou unfasten your seat belt or open the
driver's door
Rthe vehicle starts to roll
Rthe brake system requires this
Rthe temperature in the vehicle interior devi-
ates from the set range
Rthe system detects moisture on the wind-
shield when the air-conditioning system is
switched on
Rthe battery's condition of charge is too low
iShifting the transmission to position P
does not start the engine.
Deactivating or activating the ECO
start/stop function
All vehicles (except Mercedes-AMG vehi-
cles)
XTo deactivate: press ECO button :.
Indicator lamp ;goes out.
XTo activate: press ECO button :.
Indicator lamp ;lights up.
If the indicator lamp on the ECO button is off,
the ECO start/stop function has been deac-
tivated manually or as the result of a mal-
function.
Mercedes-AMG vehicles
XTo deactivate: in drive program C, press
ECO button :.
or
XSwitch to drive program S,S+ orM
(
Ypage 163).
Indicator lamp ;goes out.
XTo activate: press ECO button :.
Indicator lamp ;lights up.
156Driving
Driving and parking