MERCEDES-BENZ C300 4MATIC 2008 W204 Owner's Manual

250 Controls in detail
Dual-zone automatic climate control
Dual-zone automatic climate control panel
Item
1Temperature control, driver’s side
2´Automatic climate control
on/off
3MAX COOL on/off (USA only)
zAdopting driver’s side set-
tings for all zones
(Canada only)
Item
42AC cooling on/off
5yFront defroster
6Temperature control, passenger side
7,Air recirculation
8¯Rear window defroster
9QIncreasing air volume
Item
a·Decreasing air volume
bDisplay
cZAir distribution
dUAir distribution and air vol-
ume (automatic mode)

251 Controls in detail
Dual-zone automatic climate control
The dual-zone automatic climate control is
operational whenever the engine is run-
ning. You can operate the dual-zone auto-
matic 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.
It can only function optimally when you are
driving with the windows and the tilt/slid-
ing sunroof/panorama sunroof* closed.
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 258).
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 248) to direct the air to
air vents in the vehicle interior that are not
in the immediate area of unprotected skin.
Warning!G
Severe 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 and the
windows could fog up, impairing visibility
and endangering you and others. Have a
clogged filter replaced as soon as possible
at an authorized Mercedes-Benz Center.
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.

252 Controls in detail
Dual-zone automatic climate control
Deactivating the climate control
system
Deactivating: Press button´
(
page 250).
The indicator lamp in the button comes
on.
Reactivating: Make sure the ignition is
switched on.
Press button´ (page 250) again.
The indicator lamp in the button goes
out.The previous settings are once
again in effect.
or,
Press buttonU (page 250) while
the engine is running.
The indicator lamp in the button comes
on. The air volume and air distribution
are adjusted automatically.
iKeep the air intake grille in front of the wind-
shield free of snow and debris.
Do not obstruct air flow by placing objects on the
air flow-through exhaust slots below the rear
window.
iIf the vehicle interior is hot, ventilate the in-
terior before driving off, see “Summer opening
feature” (
page 123). The climate control will
then adjust the interior temperature to the set
value much faster.
Warning!G
When the climate control is switched off, the
outside air supply and circulation are also
switched off. Only choose this setting for a
short time. Otherwise the windows could
fog up, impairing visibility and endangering
you and others.

253 Controls in detail
Dual-zone automatic climate control
Operating the climate control system
in automatic mode
Activating: Press buttonU
(
page 250) while the engine is run-
ning.
The indicator lamp in the button comes
on. The air volume and air distribution
are adjusted automatically.
Use temperature controls1 and6
(
page 250) to separately adjust the
air temperature on each side of the
passenger compartment.
The temperature of the vehicle interior
is adjusted automatically.
Deactivating: Press buttonU
(
page 250) again.
The indicator lamp in the button goes
out. The automatic operation of air vol-
ume and air distribution switches off.
The symbols of air distribution and air
volume appear in displayb.
Adjust air distribution (page 254).
Adjust air volume (page 254).
Setting the temperature
Use temperature controls1 and6
(
page 250) 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).
The climate control will adjust to the set
temperature as fast as possible.
Increasing: Turn temperature
control1 and/or6 (
page 250)
slightly clockwise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing: Turn temperature
control1 and/or6 (
page 250)
slightly counterclockwise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
iWhen operating the climate control system
in automatic mode, you will only rarely need to
adjust the temperature, air volume and air distri-
bution.
In automatic mode, cooling with dehumidify is
switched on. This function can be switched off if
necessary (
page 258).

254 Controls in detail
Dual-zone automatic climate control
Adjusting air distribution
Use buttonZ (
page 250) to adjust
the air distribution manually. The following
symbols are shown in displayb:
Press buttonZ (page 250) re-
peatedly until you have select the de-
sired setting and the corresponding
symbol is shown in displayb.
The indicator lamp in buttonU goes
out. The automatic air distribution is
switched off. The air distribution is
controlled according to the selected
control setting.
Adjusting air volume
Seven blower speeds are available.
Press button· to decrease
orQ (
page 250) to increase air
volume to the desired level.
The indicator lamp in buttonU
(
page 250) goes out.
The air volume is adjusted correspond-
ing to the set blower speed. The auto-
matic air distribution remains switched
on.Using driver-side settings for all tem-
perature zones (Canada only)
You can use the settings of the driver’s
side, such as temperature, air volume and
air distribution, for all temperature zones.
Activating: Press buttonz
(
page 250).
The indicator lamp in the button comes
on.
The driver-side settings are used for all
temperature zones.
Deactivating: Press buttonz
(
page 250) again.
The indicator lamp in the button goes
out.
SymbolFunction
{Directs air to the windshield
and the side defroster vents
aDirects air through the center,
side and rear passenger
compartment air vents
YDirects air to the footwells
iYou can also select a position between two
symbols with buttonZ.

255 Controls in detail
Dual-zone automatic climate control
Front defroster
You can use this setting to defrost the
windshield, for example if it is iced up.
You can also defog the windshield and the
side windows.
Activating: Press buttony
(
page 250).
The indicator lamp in the button comes
on.
The air conditioning switches
automatically to the following func-
tions:

cooling on to dehumidify

most efficient blower speed and
heating power, depending on
outside temperature

air flows onto the windshield
and the front side windows

the air recirculation mode is
switched off
Deactivating: Press buttony
(
page 250) again.
The indicator lamp in the button goes
out. Defrosting is turned off.
The previous settings are once again in
effect.Windshield fogged on the outsideSwitch the windshield wipers on
(
page 117).
If the automatic mode of the climate con-
trol is switched off:
Press buttonZ (page 250) re-
peatedly until one of the following sym-
bols appears in displayb:a
orY (
page 250).
iKeep this setting selected only until the
windshield or the side windows are clear again.
iYou can adjust the temperature and the air
volume when the front defroster is switched on.
iTo switch defrosting off, you can also press
button´, U,·,Q or temperature
controls1 and6 (
page 250).
iThe cooling remains switched on.
iKeep this setting selected only until the
windshield is clear again.

256 Controls in detail
Dual-zone automatic climate control
Maximum cooling MAX COOL
(USA only)
You can use this setting to provide the fast-
est possible cooling of the vehicle interior
(when windows and tilt/sliding sunroof or
tilt/sliding panel* are closed).
Activating: Press button3
(
page 250).
The indicator lamp in the button comes
on.
The air conditioning switches
automatically to the following functions:

maximum cooling

maximum blowing power

the air recirculation mode is switched
on
Deactivating: Press button3
(
page 250) again.
The indicator lamp in the button goes
out. The previous settings are once
again in effect.
Rear window defroster
Activating: Switch on the ignition.
Press button¯ (page 250).
The indicator lamp in the button comes
on.
iTo switch the maximum cooling function off,
you can also press button ´, U ory
(
page 250).
Warning!G
Any accumulation of snow and ice should be
removed from the rear window before driv-
ing. Visibility could otherwise be impaired,
endangering you and others.
!The rear window defroster uses a large
amount of power. To keep battery drain to a min-
imum, switch off the defroster as soon as the
rear window is clear.

257 Controls in detail
Dual-zone automatic climate control
Deactivating: Press button¯
(
page 250).
The indicator lamp in the button goes
out.
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 250).
The indicator lamp in the button comes
on.
Deactivating: Press button,
(
page 250) again.
The indicator lamp in the button goes
out.
iThe rear window defroster is automatically
deactivated after some time of operation de-
pending on the outside temperature.
iIf the rear window defroster switches off too
soon and the indicator lamp goes out, this indi-
cates that too many electrical consumers are op-
erating simultaneously and the load on the
battery is reducing available voltage. The system
responds automatically by deactivating the rear
window defroster.
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 258) is activated, or
press buttony.
iThe air recirculation mode is activated auto-
matically at high outside temperatures.
The indicator lamp in button, is not lit when
the air recirculation mode is automatically
switched on.
A quantity of outside air is added after approxi-
mately 30 minutes.
iThe air recirculation mode is deactivated au-
tomatically:

after 5 minutes if the outside temperature is
below approximately 41°F (5°C)

after 5 minutes if the air conditioning is
turned off

after 30 minutes if the outside temperature
is above approximately 41°F (5°C)

258 Controls in detail
Dual-zone automatic climate control
Air conditioning
The cooling function, 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.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.
Deactivating: Press button2
(
page 250).
The indicator lamp in the button goes
out.
The cooling function switches off after
a short delay.
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Activating: Press button2
(
page 250) again.
The indicator lamp in the button comes
on.
The air conditioning uses the
refrigerant R134a. This refrigerant is free
of CFCs which are harmful to the ozone
layer.
Warning!G
If you turn off the cooling function, the
vehicle will not be cooled when weather
conditions are warm and the interior air is
not dried. The windows can fog up more
quickly. Window fogging may impair visibili-
ty and endanger you and others.
iCondensation may drip out from underneath
the vehicle. This is normal and not an indication
of a malfunction.
!If the air conditioning cannot be turned on
again, this indicates that the air conditioning is
losing refrigerant. The compressor has turned it-
self off.
Have the air conditioning checked at the nearest
authorized Mercedes-Benz Center.

259 Controls in detail
3-zone automatic climate control* (Canada only)
3-zone automatic climate control* (Canada only)
3-zone automatic climate control panel, front
Item
1Temperature control, driver’s side
2UAir distribution and air vol-
ume (automatic mode)
3´Automatic climate control
on/off
4zAdopting driver’s side set-
tings for all zones
Item
52AC cooling on/off
6TResidual engine
heat/ventilation
7yFront defroster
8Temperature control, passenger side
9¯Rear window defroster
Item
aZAir distribution, passenger
side
bQIncreasing air volume
c·Decreasing air volume
dDisplay
eZAir distribution, driver’s side
f,Air recirculation