Page 186 of 514

185 Controls in detail
Good visibility
Rear window defroster
The rear window defroster uses a large
amount of power. To keep the battery
drain to a minimum, switch off the
defroster as soon as the rear window is
clear. The defroster is automatically
deactivated after approximately
6 to 17 minutes of operation depending on
the outside temperature.Activating
Press buttonF or1 in the
climate control panel (
page 187) or
automatic climate control panel
(
page 197).
The indicator lamp on the button
comes on.
Deactivating
Press buttonF or1 again.
The indicator lamp on the button goes
out.
Warning!
G
Any accumulation of snow and ice should be
removed from the rear window before
driving. Visibility could otherwise be
impaired, endangering you and others.!If the rear window defroster switches
off too soon and the indicator lamp
starts flashing, this means that too
many electrical consumers are
operating simultaneously and there is
insufficient voltage in the battery. The
system responds automatically by
deactivating the rear window defroster.
As soon as the battery has sufficient
voltage, the rear window defroster
automatically switches on again.
Page 189 of 514

188 Controls in detailClimate control (CLK 350)The climate control is operational when-
ever the engine is running. You can oper-
ate the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 194).
Warning!
G
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature).
This may cause burns or frostbite on unpro-
tected skin in the immediate area of the air
vents. Always keep sufficient distance be-
tween unprotected parts of the body and the
air vents. If necessary, use the air distribu-
tion control (
page 187) to direct the air to
air vents in the vehicle interior that are not
in the immediate area of unprotected skin.
Warning!
G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air
pollution) may require replacement of
the filter before its scheduled interval.
A clogged filter will reduce the air
volume to the interior.
If the vehicle interior is hot, ventilate
the interior before driving off, see
“Summer opening feature”
(page 252). The climate control will
then adjust the interior temperature to
the set value much faster.
Keep the air intake grille in front of the
windshield free of snow and debris.
Do not obstruct air flow by placing
objects on the air flow-through exhaust
slots below the rear window.
Page 193 of 514

192 Controls in detailClimate control (CLK 350)Windshield fogged on the outside
Switch the windshield wipers on
(page 54).
Press button U (
page 187).
The indicator lamp on the button
comes on. Air distribution and air vol-
ume are adjusted automatically.
If the automatic mode of the climate con-
trol is switched off:
Turn air distribution control4 to
aor Y (
page 187).
Air recirculation mode
Switch to air recirculation mode to prevent
unpleasant odors from entering the vehicle
from the outside (e.g. before driving
through a tunnel). This setting cuts off the
intake of outside air and recirculates the
air in the passenger compartment.Activating
Press button, (
page 187).
The indicator lamp on the button
comes on.
iKeep this setting selected only until the
windshield is clear again.
Warning!
G
Fogged windows impair visibility, endanger-
ing 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 (
page 194) is activated, or
press buttonP or0.
iThe air recirculation mode is activated
automatically at high outside tempera-
tures.
The indicator lamp on button, is
not lit when the air recirculation mode
is automatically switched on.
A quantity of outside air is added after
approximately 30 minutes.
Page 194 of 514

193 Controls in detail
Climate control (CLK 350)
Deactivating
Press button, (
page 187).
The indicator lamp on the button goes
out.
Warning!
G
Never operate the side windows if there is
the possibility of anyone being harmed by
the closing procedure.
In the event that the procedure causes po-
tential danger, the closing of the side win-
dows can be immediately halted by
releasing the, button or by pressing or
pulling the respective window switch.iIf you press and hold button,, the
side windows will close.
iThe air recirculation mode is deactivat-
ed automatically:
after 5 minutes if the outside
temperature is below
approximately 41°F (5°C)
after 5 minutes if the air condition-
ing is turned off
after 30 minutes if the outside
temperature is above
approximately 41°F (5°C)
iIf you press and hold button,, the
side windows will return to their previ-
ous position.
A side window will only return to its pre-
vious position if it has not been moved
to another position using the respec-
tive side window switch after it was
closed with button,. A side win-
dow that was moved will remain in its
current position if button, is used
to re-open the remaining side windows.
Page 195 of 514

194 Controls in detailClimate control (CLK 350)Air conditioning
The cooling function, is only operational
when the engine is running, cools the vehi-
cle interior down to the selected tempera-
ture. The cooling function also
dehumidifies the air in the vehicle interior,
thus preventing the windows from fogging
up.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the climate
control system. The air in the vehicle will
then no longer be cooled or dehumidified.
Press button2(
page 187).
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Press button2(
page 187) again.
The indicator lamp on the button
comes on.
The air conditioning uses the
refrigerant R134a. This refrigerant is free
of CFCs which are harmful to the ozone
layer.
iCondensation may drip out from under-
neath the vehicle. This is normal and
not an indication of a malfunction.Warning!
G
If you turn 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.
!If the air conditioning cannot be turned
on again, this indicates that the air
conditioning is losing refrigerant. The
compressor has turned itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Center.
Page 199 of 514

198 Controls in detailAutomatic climate control (CLK 500/CLK 55 AMG)The automatic climate control is operation-
al whenever the engine is running. You can
operate the climate control system in ei-
ther the automatic or manual mode. The
system cools or heats the interior depend-
ing on the selected interior temperature
and the current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air
enters the passenger compartment
through the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 206).
Warning!
G
When operating the automatic climate
control, the air that enters the passenger
compartment through the air vents can be
very hot or very cold (depending on the set
temperature). This may cause burns or frost-
bite on unprotected skin in the immediate
area of the air vents. Always keep sufficient
distance between unprotected parts of the
body and the air vents. If necessary, use the
air distribution controls (
page 197) to
direct the air to air vents in the vehicle inte-
rior that are not in the immediate area of un-
protected skin.
Warning!
G
Follow the recommended settings for
heating and cooling given on the following
pages. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air
pollution) may require replacement of
the filter before its scheduled interval.
A clogged filter will reduce the air
volume to the interior.
If the vehicle interior is hot, ventilate
the interior before driving off, see
“Summer opening feature”
(page 252). The automatic climate
control will then adjust the interior
temperature to the set value much
faster.
Keep the air intake grille in front of the
windshield free of snow and debris.
Do not obstruct air flow by placing
objects on the air flow-through exhaust
slots below the rear window.
Page 204 of 514

203 Controls in detail
Automatic climate control (CLK 500/CLK 55 AMG)
Air recirculation mode
Switch to air recirculation mode to prevent
unpleasant odors from entering the vehicle
from the outside (e.g. before driving
through a tunnel). This setting cuts off the
intake of outside air and recirculates the
air in the passenger compartment.Activating
Press button, (
page 197).
The indicator lamp on the button
comes on.
Warning!
G
Fogged windows impair visibility, endanger-
ing 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 (
page 206) is activated, or
press buttonP or 0.
iThe air recirculation mode is activated
automatically at high outside tempera-
tures.
The indicator lamp on the button,
is not lit when the air recirculation
mode is automatically switched on.
A quantity of outside air is added after
approximately 30 minutes.
Warning!
G
Never operate the side windows if there is
the possibility of anyone being harmed by
the closing procedure.
In the event that the procedure causes po-
tential danger, the closing of the side win-
dows can be immediately halted by
releasing the, button or by pressing or
pulling the respective window switch.iIf you press and hold button,, the
side windows will close.
Page 206 of 514

205 Controls in detail
Automatic climate control (CLK 500/CLK 55 AMG)
Activating
Press buttone (
page 197).
The indicator lamp on the button
comes on.Deactivating
Press buttone (
page 197).
The indicator lamp on the button goes
out.
iIf you press and hold buttone, the
side windows will close.iThe activated charcoal filter should be
switched off when windows fog up on
the inside, or if the passenger compart-
ment needs to be quickly heated or
cooled down.
Warning!
G
Never operate the side windows if there is
the possibility of anyone being harmed by
the closing procedure.
In the event that the procedure causes po-
tential danger, the closing of the side win-
dows can be immediately halted by
releasing thee button or by pressing or
pulling the respective window switch.
iIf you press and hold buttone, the
side windows will return to their previ-
ous position.
A side window will only return to its pre-
vious position if it has not been moved
to another position using the respec-
tive side window switch after it was
closed with buttone. A side win-
dow that was moved will remain in its
current position if button e is used
to re-open the remaining side windows.