2008 MERCEDES-BENZ C300 C S button

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.

261 Controls in detail
3-zone automatic climate control* (Canada only)
Deactivating climate control system
Deactivating: Press button´
(
page 259).
The indicator lamp in the button comes
on.
Reactivating: Make sure the ignition is
switched on.
Press button´ (page 259) again.
The indicator lamp in the button goes
out.The previous settings are once
again in effect.
or,
Press buttonU (page 259) while
the engine is running.
The indicator lamp in the button comes
on. The air volume and air distribution
are adjusted automatically.Operating climate control system in
automatic mode
Activating: Press buttonU
(
page 259) 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 and8
(
page 259) to separately adjust the
air temperature on each side of the
passenger compartment.
The temperature of the vehicle interior
is adjusted automatically.
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.
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.

262 Controls in detail
3-zone automatic climate control* (Canada only)
Deactivating: Press buttonU
(
page 259) 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 displayd.
Adjust air distribution (page 263).
Adjust air volume (page 263).
Setting the temperature
Use temperature controls1 and/or8
(
page 259) 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/or8 (
page 259)
slightly clockwise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing: Turn temperature
control1 and/or8 (
page 259)
slightly counterclockwise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
iYou can also adjust the temperature in the
rear passenger compartment (
page 268).
iIf you turn the temperature control fully
clockwise for one side of the vehicle, you are in-
creasing the temperature for the other side of
the vehicle as well.
iIf you turn the temperature control fully
counterclockwise for one side of the vehicle, you
are decreasing the temperature for the other
side of the vehicle as well.

263 Controls in detail
3-zone automatic climate control* (Canada only)
Adjusting air distribution
Use righta and/or lefte buttonZ
(
page 259) to adjust the air distribution
manually for each side of the passenger
compartment. The following symbols are
shown in displayd:
Press buttonsZ (page 259) re-
peatedly until you have select the de-
sired setting and the corresponding
symbol is shown in displayd.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
Use buttonU (
page 259) for auto-
matic mode or button · (
page 259)
orQ (
page 259) to adjust air volume
manually.
Seven blower speeds are available for each
side of the passenger compartment.
Press button· to decrease, or
buttonQ to increase air volume to
the desired level.
The indicator lamp in buttonU
(
page 259) 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
You can use the settings of the driver’s
side, such as temperature, air volume and
air distribution, for all temperature zones.
Press buttonz (page 259).
The indicator lamp in the button comes
on.
The driver-side settings are used for all
temperature zones.
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.

264 Controls in detail
3-zone automatic climate control* (Canada only)
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 259).
The indicator lamp in the button comes
on.
The air conditioning switches
automatically to the following functions:

cooling on to dehumidify

most efficient blower speed and
heating power, depending on out-
side temperature

air flows onto the windshield and
the front side windows

the air recirculation mode is
switched off
Deactivating: Press buttony
(
page 259) 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 118).
If the automatic mode of the climate con-
trol is switched off:
Press righta and/or lefte air distri-
bution buttonZ (
page 259) re-
peatedly until one of the following
symbols appears in
displayd:aorY
(
page 259).
iKeep this setting selected only until the
windshield is clear again.
iYou can adjust the air distribution when the
front defroster is switched on.
iTo switch defrosting off, you can also press
button´, U,·,Q or temperature
controls1 and8 (
page 259).
iThe cooling remains switched on.
iKeep this setting selected only until the
windshield is clear again.

265 Controls in detail
3-zone automatic climate control* (Canada only)
Rear window defroster
Activating: Switch on the ignition.
Press button¯ (page 259).
The indicator lamp in the button comes
on.
Deactivating: Press button¯
(
page 259).
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.
!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.
iThe rear window defroster is automatically
deactivated after some time of operation de-
pending on the outside temperature.
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.
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 267) is activated, or
press buttony.

266 Controls in detail
3-zone automatic climate control* (Canada only)
Activating: Press button,
(
page 259).
The indicator lamp in the button comes
on.
Deactivating: Press button,
(
page 259) again.
The indicator lamp in the button goes
out.
Residual engine heat and ventilation
With the engine switched off, it is possible
to continue to heat or ventilate the interior
for approximately 30 minutes. This feature
makes use of the residual heat produced
by the engine.
Activating: Switch off the ignition.
Press buttonT (page 259).
The indicator lamp in the button comes
on.
Deactivating: Press buttonT
(
page 259) again.
The indicator lamp in the button goes
out.
iThe air recirculation mode is activated auto-
matically at high outside temperatures.
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 approxi-
mately 30 minutes.
iThe air recirculation mode is deactivated au-
tomatically:

after 5 minutes if the outside temperature is
below approximately 7°C (45°F)

after 5 minutes if the air conditioning is
turned off

after 30 minutes if the outside temperature
is above approximately 5°C (41°F)
iIf you switch on the residual heat function
when outside temperatures are high, only the
ventilation will be switched on.
iRegardless of the selected air volume, the
blower operates at low speed when heating. In
case of ventilation the blower operates at higher
speed.
iHow long the system will provide heating de-
pends on

the coolant temperature

the temperature set by the operator
iThe residual heat is automatically turned off:

when the ignition is switched on

after approximately 30 minutes

if the battery voltage drops

if the coolant temperature is too low

267 Controls in detail
3-zone automatic climate control* (Canada only)
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.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.
iCondensation may drip out from underneath
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 it-
self off.
Have the air conditioning checked at the nearest
authorized Mercedes-Benz Center.