2007 MERCEDES-BENZ C350 air conditioning

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.

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.

181 Controls in detail
Automatic climate control
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 175).
The indicator lamp on the button
comes on.DeactivatingPress button, (page 175) again.
The indicator lamp on the button goes
out.
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 175) is activated, or
press buttonP or 0.
iThe air recirculation mode is activated auto-
matically at high outside temperatures.
The indicator lamp on the 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)

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.

185 Controls in detail
Automatic climate control
Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condi-
tioning.
Press button2 or9
(
page 175) 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.Residual heat and ventilation
(Canada only)
With the engine switched off, it is possible
to continue to heat or ventilate the interior
for up to 30 minutes. This feature makes
use of the residual heat produced by the
engine.ActivatingSwitch off the ignition (page 32).
Press button9 (page 175).
The indicator lamp on the button
comes on.
Deactivating
Press button9 (page 175).
The indicator lamp on the button goes
out.
The residual heat is automatically turned
off:

when the ignition is switched on

after about 30 minutes

if the battery voltage drops
!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.
iHow long the system will provide heating de-
pends on

the coolant temperature

the temperature set by the operator
The blower will run at speed setting 1 regardless
of the air distribution control setting.

186 Controls in detail
Automatic climate control
Rear passenger compartment
adjustable air vents
The air conditioning for the rear passenger
compartment is controlled via the auto-
matic climate control panel (
page 175).The air vents for the rear passenger
compartment are located in the rear
center console.
1Left center air vent
2Thumbwheel for air volume control for
center air vents
3Right center air ventAdjusting air distribution
Push the slide for the left center
vent1 or right center vent3 to the
left, right, up, or down.
The air flow is directed in the
corresponding direction.
Adjusting air volume
Turn thumbwheel2 up or down.
The air volume is increased or
decreased.
iThe temperature at the center air vents1
and3 for the rear passenger compartment is
the same as at the dashboard center air vents.
iFor draft-free ventilation, move the sliders
for the center air vents1 and3 upward.

304 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 three hours or
driven no more than one 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 is specific to each vehicle and may vary
from data shown in above illustration.

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