2008 MERCEDES-BENZ C300 4MATIC air conditioning

260 Controls in detail
3-zone automatic climate control* (Canada only)
The 3-zone automatic climate control is
operational whenever the engine is run-
ning. You can operate the 3-zone automat-
ic 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.It is possible to completely deactivate the
3-zone automatic climate control system
(
page 261).
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 267).
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
distribution control (page 248) to direct
the air to air vents in the vehicle interior that
are not in the immediate area of unprotect-
ed 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.
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.

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.

356 Operation
Tires and wheels
Tire ply material
1Plies in sidewall
2Plies under tread
This marking tells you about the type of
cord and number of plies in the sidewall
and under the tread.Tire and loading terminology
Accessory weight
The combined weight (in excess of those
standard items which may be replaced) of
automatic transmission, power steering,
power brakes, power windows, power
seats, radio, and heater, to the extent that
these items are available as
factory-installed equipment (whether
installed or not).
Air pressure
The amount of air inside the tire pressing
outward on each square inch of the tire.
Air pressure is expressed in pounds per
square inch (psi), or kilopascal (kPa) or
bars.
Aspect ratio
Dimensional relationship between tire
section height and section width
expressed in percentage.Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least 3 hours or driv-
en no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.
iFor illustration purposes only. Actual data
on tires are specific to each vehicle and may vary
from data shown in above illustration.

464 Technical data
Layout of poly-V-belt drive
C 300/C 350
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)

478 Technical data
Fuels, coolants, lubricants, etc.
ModelCapacityFuels, coolants, lubricants, etc.
Power steeringAll models0.85 US qt. (0.8 l)MB Power Steering Fluid
(Chevron Texaco PSF 9109)1
1For detailed information, please refer to the Factory Approved Service Products pamphlet (USA only) or contact an authorized Mercedes-Benz Center.
Front wheel hubsAll modelsapprox. 3.6 oz. (95 g) eachHigh-temperature roller bearing grease
Brake systemAll modelsapprox. 0.53 US qt. (0.5 l)MB Brake Fluid (DOT 4+)
Cooling systemAll models5.07 US qt. (4.8 l)MB 325.0 Anticorrosion/Antifreeze
Fuel tank
including a reserve ofAll models17.43 US gal (66.0 l)
2.11 US gal (8.0 l)Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)
C 300 and C 300 Sport (with automatic
transmission*), USA only:
Flexible Fuel Vehicle (identified by a label
reading Premium gasoline or E85 only!
on fuel filler flap).
Alternative fuel: Ethanol fuel (E85)
Air conditioning systemAll modelsR-134a refrigerant and special PAG
lubricant oil (never R-12)