2007 MERCEDES-BENZ C280 cooling

176 Controls in detail
Automatic climate control
The automatic climate control is operation-
al whenever the engine is running. You can
operate the automatic climate control sys-
tem in either the automatic or manual
mode. The system cools or heats the inte-
rior depending on the selected interior
temperature and the current outside tem-
perature.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 theA/C mode is deactivated
(
page 184).
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 control (
page 178) 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
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 fea-
ture” (
page 223). The automatic climate con-
trol will then adjust the interior temperature to
the set value much faster.
Keep 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.

177 Controls in detail
Automatic climate control
Deactivating the automatic climate
control system
Deactivating
Press button´ (page 175).
The indicator lamp on the button
comes on.
Reactivating
Press button´ (page 175).
The indicator lamp on the button goes
out. The previous settings are once
again in effect.Operating the automatic climate con-
trol system in automatic mode
Activating
Press buttonU (page 175) while
the engine is running.
The indicator lamp on the button
comes on. The air volume and air distri-
bution are adjusted automatically.1Temperature, left
2Blower speed
3Temperature, right
Use temperature controls3 and
dor6 and b (
page 175) to sepa-
rately adjust the air temperature on
each side of the passenger compart-
ment.
The temperature of the vehicle interior
is adjusted automatically.
Deactivating
Press buttonU (page 175) again.
The indicator lamp on the button goes
out. The automatic operation of air vol-
ume and air distribution switches off.
Warning!G
When the automatic climate control is
switched off, the outside air supply and cir-
culation 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 automatic climate con-
trol system in automatic mode, you will only rare-
ly need to adjust the temperature, air volume
and air distribution.
In automatic mode, the dehumidify function is
switched on when the system is cooling. If nec-
essary, this function can be switched off by
pushing the button2 or 9 (
page 175).
iYou can switch the automatic climate con-
trol system on and off for each side of the pas-
senger compartment as desired.

179 Controls in detail
Automatic climate control
The automatic air distribution is
switched off. The air distribution is
controlled according to the selected
control setting.
Opening center and side air vents
Turn thumbwheels 3, 4, 7 and 8
(
page 174) upward.
The center air vents 5 and 6 and side
air vents 2 and 9 (
page 175) are
open.
Closing center and side air vents
Turn thumbwheels 3, 4, 7 and 8
(
page 174) downward.
The center air vents 5 and 6 and side
air vents 2 and 9 (
page 174) are
closed.
Adjusting air volume
Use buttonU (
page 175) for auto-
matic mode or air volume controls

orQ (
page 175) to adjust air volume
manually.
Seven blower speeds are available.
Press button
to decrease
orQ (
page 175) to increase air
volume to the desired level.
The indicator lamp on the buttonU
goes out.
The automatic air distribution remains
switched on.
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 buttonP or 0
(
page 175).
The indicator lamp on the button
comes on.
The air conditioning switches
automatically to the following functions:

cooling on to dehumidify

maximum blowing and heating
power

air flows onto the windshield and
the front side windows

the air recirculation mode is
switched off
iYou can also turn the air distribution control
to a position between two symbols.
iKeep this setting selected only until the
windshield or the side windows are clear again.

180 Controls in detail
Automatic climate control
Deactivating
Press buttonP or 0
(
page 175) again.
The indicator lamp on the button goes
out.
The previous settings are once again in
effect.Windshield fogged on the outside
Switch the windshield wipers on
(
page 51).
If the automatic mode of the automatic cli-
mate control is switched off:
Turn air distribution control1 or8
toa orY (
page 175).
Maximum cooling MAXCOOL
If the left and right air distribution controls
as well as the airflow volume control are
set toU (
page 175) and there is a
high need for cooling, the display
“MAXCOOL” appears.
This provides the fastest possible cooling
of the vehicle interior (when side windows
and tilt/sliding sunroof* are closed).
iIf you have switched on the defrost function
using thePor0 button, you cannot
make any other settings.
iThe cooling remains switched on.
iKeep this setting selected only until the
windshield is clear again.

184 Controls in detail
Automatic climate control
Deactivating
Press buttone (page 175).
The indicator lamp on the button goes
out.
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.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the
vehicle will then no longer be cooled or
dehumidified.
Press button2 or9
(
page 175).
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.
iPress and hold buttone for approx.
2 seconds. The side windows and or tilt/sliding
sunroof* will return to their previous position.
You can release buttone once the opening
procedure has begun. The windows and tilt/slid-
ing sunroof* continue opening until they have
reached their previous position.
A window or tilt/sliding sunroof* will only return
to its previous position if it has not been moved
to another position using the respective window
switch or tilt/sliding sunroof* switch after it was
closed with buttone. A window or tilt/slid-
ing sunroof* that was moved will remain in its
current position if buttone is used to
re-open the remaining windows or tilt/sliding
sunroof*.
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.

190 Controls in detail
Audio system
Button and soft key operation
In these instructions, the alphanumeric
keypad (right side of radio panel) and the
function buttons (left side of radio panel)
are referred to as “buttons”. The four keys
below the display panel are referred to as
“soft keys”.Operation
Switching the unit on/off
Switching on
Turn the SmartKey in the starter switch
to position1 or2.
If the audio system was on as you
removed the SmartKey from the starter
switch, the audio system will
automatically come back on as you
turn the SmartKey to position1 or2.
or
Press M button.Switching off
Remove SmartKey from starter switch.
or
Press M button.
Adjusting the volume
Turn rotary control of N button.
The volume will increase or decrease
depending on the direction turned.
!Do not press directly in the display face.
Otherwise, the display will be damaged.
iIf the radio is switched on without the Smart-
Key in the starter switch, it will automatically
switch off again after approx. 30 minutes.
If your vehicle is equipped with a telephone, the
display may prompt you to enter your PIN (GSM
network) or code (TDMA or CDMA network).
iShould excessively high temperatures occur
while the audio system is being operated, the
display will dim. If temperatures continue to rise,
HIGH TEMP will appear in the display, after which
the audio system will be switched off for a
cooling-down period.
iIf your vehicle equipment includes a Mer-
cedes-Benz specified mobile telephone*, you
can adjust its volume separately from the volume
of the audio system while the telephone is being
used.

278 Operation
Engine compartment
Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Coolant expansion tank
2CapUsing a rag, turn cap2 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning the cap counterclock-
wise and remove it.
The coolant level is correct if the level

for cold coolant: reaches the black
top part of the reservoir

for warm coolant: is approx. 0.6 in
(1.5 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information on coolant, see
“Coolants” (
page 416).
Warning!G
In order to avoid any potentially serious
burns:

Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.

Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.

Using a rag, slowly open the cap
approximately1/2 turn to relieve excess
pressure. If opened immediately, scald-
ing hot fluid and steam will be blown out
under pressure.

Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.

345 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
BTop up
coolant
See
Operator’s
ManualThe coolant level is too low.Add coolant (page 278).
If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Center.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with the message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz Lim-
ited Warranty.
Do not drive without sufficient amount of coolant
in the cooling system. The engine will overheat
causing major engine damage.