Page 189 of 498

187 Controls in detail
Climate control (CLK 320)
Deactivating the climate control system
Deactivating
Set air volume control1 (
page 185) 
to position0. 
Reactivating
Set air volume control1 (
page 185) 
to any speed.
Setting the temperature
Use temperature controls2 and3 
(page 185) to separately adjust the air 
temperature on each side of the passenger 
compartment. You should raise or lower 
the temperature setting in small incre-
ments, preferably starting at 72°F (22°C).
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 
“Opening (Summer opening feature)” 
(page 253).
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.
iWhen the air conditioning is switched 
off, the outside air supply and circula-
tion are also switched off. Only choose 
this setting for a short time. Otherwise 
the windows could fog up.
iWhen operating the climate control 
system in automatic mode, you will 
only rarely need to adjust the tempera-
ture, air volume and air distribution. 
     
        
        Page 190 of 498

188 Controls in detailClimate control (CLK 320)Increasing
Turn temperature control2 or3 
(page 185) slightly to the right.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing
Turn temperature control2 or3 
(page 185) slightly to the left.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Adjusting air distribution and volume
Use air distribution control4 
(page 185) to adjust the air distribution. 
The following symbols are found on the 
controls:
Use the air volume control1 
(page 185) to adjust the air volume. You 
can select between six air volume speeds.Adjusting manually
Press buttonU (
page 185).
The indicator lamp on the button goes 
out.
Select any of the six air volume speeds 
and the air distribution.
Adjusting automatically
Press buttonU (
page 185).
The indicator lamp on the button 
comes on. The temperature, air distri-
bution and volume are adjusted auto-
matically.
Symbol
Function
Z
Directs air to the windshield 
and the side defroster vents
b
Directs air into the entire 
vehicle interior
Y
Directs air to the footwells
a
Directs air through the center, 
side and rear passenger 
compartment air vents 
     
        
        Page 191 of 498
189 Controls in detail
Climate control (CLK 320)
Windshield fogged on the outside
Switch the windshield wipers on 
(page 51).
Switch to manual mode.
Turn the air distribution control4 
toa orY (
page 185).
Defrosting
Activating
Press buttonP or0 
(page 185). 
The indicator lamp on the button 
comes on.
The air conditioning switches 
automatically to the following functions:
maximum blowing and heating 
power
air flows onto the windshield and 
the front side windows
the air recirculation mode is 
switched offDeactivating
Press buttonP or0 
(page 185). 
The indicator lamp on the button goes 
out. Defrosting is turned off.
iThese settings should only be selected 
for a short time. 
     
        
        Page 192 of 498

190 Controls in detailClimate control (CLK 320)Air recirculation mode
Switch to air recirculation mode to prevent 
unpleasant odors from entering the vehicle 
from the outside. This setting cuts off the 
intake of outside air and recirculates the 
air in the passenger compartment.
Activating
Press button, (
page 185).
The indicator lamp on the button 
comes on.
Warning!
G
When the outside temperature is 
below 41°F (5°C), only switch to air 
recirculation mode for short periods to 
prevent window fogging.
Window fogging may impair visibility and 
endanger you and others.
iIf you keep button, pressed the 
side windows and tilt/sliding sunroof* 
will close.Warning
G
Never operate the side windows and the 
tilt/sliding sunroof* 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. The 
closing of the tilt/sliding sunroof* can be 
immediately halted by releasing the, 
button or by moving the tilt/sliding sunroof* 
switch in the overhead control panel in any 
direction.
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.
After approx. 30 minutes, outside air is 
added to the air inside the vehicle.
If you have turned off the air condi-
tioning (
page 191) or the outside 
temperature is below 41°F (5°C), the 
air recirculation mode will not switch 
on automatically. 
     
        
        Page 193 of 498

191 Controls in detail
Climate control (CLK 320)
Deactivating
Press button, (
page 185).
The indicator lamp on the button goes 
out.
The air recirculation mode is deactivated 
automatically:
after five minutes if the outside 
temperature is below 
approximately 41°F (5°C)
after five minutes if the air conditioning 
is turned off
after 30 minutes if the outside 
temperature is above 
approximately 41°F (5°C)At outside temperatures above 79°F 
(26°C) the system will not automatically 
switch back to outside air. A quantity of 
outside air is added after approximately 
30 minutes.
Air conditioning
The air conditioning is operational while 
the engine is running and cools the interior 
air to the temperature set by the operator.
iIf you keep button, pressed the 
side windows and tilt/sliding sunroof* 
will return to their previous position.
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. 
     
        
        Page 194 of 498

192 Controls in detailClimate control (CLK 320)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.
Climate control panel design A
Press button±(
page 185). 
The indicator lamp on the button 
comes on.
The cooling function switches off after 
a short delay.
Climate control panel design B
Press button2(
page 185). 
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.
Climate control panel design A
Press button±(
page 185) again.
The indicator lamp on the button goes 
out.
Climate control panel design B
Press button2(
page 185) 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.
!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 195 of 498
193 Controls in detail
Climate control (CLK 320)
Rear passenger compartment adjustable air vents
The air conditioning for the rear passenger 
compartment is controlled via the climate 
control panel (
page 185).The air vents for the rear passenger 
compartment are located in the rear 
center console.
1Thumbwheel for air volume control for 
center air vents
2Left center air vent
3Right center air ventAdjusting air distribution
Push the slide for the left center 
vent2 or right center vent3 to the 
left, right, up or down.
The air flow is directed in the corre-
sponding direction.
Adjusting air volume
Turn thumbwheel1 t o  t h e  l e f t  o r  r i g h t .
The air volume is increased or 
decreased.
iThe temperature at the center air vents 
for the rear passenger 
compartment2 and3 is the same as 
at the dashboard center air vents.
iFor draft-free ventilation, push 
slides2 and3 upward. 
     
        
        Page 196 of 498
194 Controls in detailAutomatic climate control (CLK 500/CLK 55 AMG)