cooling MERCEDES-BENZ C350 4MATIC 2006 W203 User Guide

189 Controls in detail
Automatic climate control* (Canada only)
Deactivating the automatic climate control system
Deactivating
Press button´ (
page 187).
The indicator lamp on the button
comes on.
The automatic climate control system
is deactivated.
Reactivating

Press button´ (
page 187).
The indicator lamp on the button goes
out.Operating the climate control system
in automatic modeActivating

Press buttonU (
page 187) 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 187) to sepa-
rately adjust the air temperature on
each side of the passenger compart-
ment.
The temperature of the vehicle interior
is adjusted automatically.
iWhen the air conditioning is switched
off, the outside air supply and circula-
tion are also switched off. Only choose
this setting for a short time. Otherwise
the windows could fog up.
iWhen operating the automatic climate
control system in automatic mode, you
will only rarely need to adjust the
temperature, air volume and air
distribution.
In automatic mode, cooling with dehu-
midify is switched on. This function can
be switched off if necessary.iThe automatic climate control system
can be switched on or off separately for
the left and right sides of the passenger
compartment, as required.

192 Controls in detailAutomatic climate control* (Canada only)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
Deactivating

Press buttonP (
page 187) 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 54).
If the automatic mode of the climate con-
trol is switched off:

Turn air distribution control1 or8
toa orY (
page 187).
Maximum cooling MAXCOOL
If the left and right air distribution controls
as well as the airflow volume control are
set toU (
page 187) 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).
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.
iThe cooling remains switched on.
iKeep this setting selected only until the
windshield is clear again.
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 187) is activated, or
press buttonP.

196 Controls in detailAutomatic climate control* (Canada only)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 button9 (
page 187).
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.
Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condi-
tioning.

Press button9 (
page 187) 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.
iCondensation may drip out from under-
neath 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 itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Center.

203 Controls in detail
Audio system
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.Adjusting sound functions
The bass and treble functions are called up
by pressing the O button.
Settings for bass and treble are stored
separately for the AM and FM wavebands,
weather band, CD mode and telephone
mode.
Bass

Press O button repeatedly until BASS
appears in the display.

Press
+ or
– soft key to increase or
decrease tone level accordingly.
or

Press
RES
soft key briefly to reset bass
tones to their center level.
The radio switches back to the
standard radio menu 8 seconds after
the last soft key is pressed.
iShould excessively high temperatures
occur while the audio system is being
operated, the display will dim. If tem-
peratures 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
Mercedes-Benz specified mobile
telephone*, you can adjust its volume
separately from the volume of the
audio system while the telephone is
being used.

301 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
2Cap

Using a rag, turn cap2 slowly approx-
imately one half turn to the left to
release any excess pressure.

Continue turning the cap to the left 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 444).
Warning!
G
In order to avoid any possibly 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
approximately
1/2 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.

371 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 301).

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 can 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 Limited
Warranty.
Do not drive without sufficient amount
of coolant in the cooling system. The
engine will overheat causing major
engine damage.

373 Practical hints
What to do if …
Display symbol
Display message
Possible cause/consequence
Possible solution
•
Coolant
Stop, engine off!
The poly-V-belt could be broken.

Stop the vehicle in a safe location and
immediately turn off the engine.

Check the poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise the engine will
overheat due to an inoperative water pump which
may result in damage to the engine. Notify an au-
thorized Mercedes-Benz Center.
If it is intact:

Do not continue to drive the vehicle with this mes-
sage displayed. Doing so could result in serious
engine damage that is not covered by the
Mercedes-Benz Limited Warranty.

Observe the coolant temperature gauge in the in-
strument cluster (
page 24).

Drive immediately to the nearest authorized
Mercedes-Benz Center.
Coolant
Visit workshop.
The cooling fan for the coolant is
malfunctioning.

Observe the coolant temperature gauge in the in-
strument cluster (
page 24).

Have the fan replaced as soon as possible.

441 Technical data
Fuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants, etc.
Power steering
approx. 1.1 US qt (1.0 l)
MB Power Steering Fluid (Pentosin
CHF 11S)
Front wheel hubs
approx. 2.1oz (60g)
each
High temperature roller bearing grease
Brake system
0.5 US qt (0.5 l)
MB Brake Fluid (DOT 4+)
Cooling system
approx. 7.5 US qt (7.1 l)
MB 325.0 Anticorrosion/antifreeze
agent
Fuel tank
including
a reserve of
16.4 US gal (62.0 l)
2.1 US gal (8.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)
Air conditioning system
R-134a refrigerant and special PAG lubri-
cant oil (never R-12)
Windshield washer
3.2 US qt (3.0 l)
MB Windshield Washer Concentrate
1
Windshield washer and headlamp
cleaning system*
6.4 US qt (6.0 l)
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing point or MB Windshield Washer Concentrate “S” and commercially available
premixed windshield washer solvent/antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 448).

444 Technical dataFuels, coolants, lubricants, etc.In areas where carbon deposits may be
encountered due to lack of availability of
gasolines which contain these additives,
Mercedes-Benz recommends the use of
additives approved by us for use on
Mercedes-Benz vehicles. Refer to Factory
Approved Service Products pamphlet for a
listing of approved product(s). Follow
directions on product label.
Do not blend other fuel additives with fuel.
This only results in unnecessary cost and
may be harmful to engine operation.
Damage or malfunction resulting from
poor fuel quality or from blending
additional fuel additives other than those
tested and approved by us for use on
Mercedes-Benz vehicles listed in the
Factory Approved Service Products
pamphlet are not covered by the
Mercedes-Benz Limited Warranty.
Fuel requirements
Only use premium unleaded fuel:

The octane number (posted at the
pu mp ) m ust b e 91 m i n. It is an a ve ra ge
of both the Research (R) octane num-
ber and the Motor (M) octane number:
(R+M)/2. This is also known as the
ANTI-KNOCK INDEX.
Unleaded gasoline containing oxygenates
such as ethanol, IPA, IBA and TBA can be
used provided the ratio of any one of these
oxygenates to gasoline does not
exceed 10%; MTBE must not exceed 15%.
The ratio of methanol to gasoline must not
exceed 3% plus additional cosolvents.
Using mixtures of ethanol and methanol is
not allowed. Gasohol, which contains 10%
ethanol and 90% unleaded gasoline, can
be used.
These blends must also meet all other fuel
requirements, such as resistance to spark
knock, boiling range, vapor pressure, etc.
Coolants
The engine coolant is a mixture of water
and anticorrosion/antifreeze, which
provides:

Corrosion protection


Freeze protection


Boiling protection (by increasing the
boiling point)
The cooling system was filled at the factory
with a coolant providing freeze protection
to approximately -22°F (-30°C) and
corrosion protection.
If the antifreeze mixture is effective
to -22°F (-30°C), the boiling point of the
coolant in the pressurized cooling system
is reached at approx. 266°F (130°C).

445 Technical data
Fuels, coolants, lubricants, etc.
The coolant solution must be used
year-round to provide the necessary corro-
sion protection and increase boil-over
protection. Refer to Maintenance Booklet
for replacement interval.
Coolant system design and coolant used
determine the replacement interval. The
replacement interval published in the
Maintenance Booklet is only applicable
if MB 325.0 anticorrosion/antifreeze
solution or other Mercedes-Benz approved
products of equal specification (see
Factory Approved Service Products
pamphlet) are used to renew the coolant
concentration or bring it back up to the
proper level.To provide important corrosion protection,
the solution must be at least 45%
anticorrosion/antifreeze [equivalent to
freeze protection to approx. -22°F
(-30°C)].
If you use a solution that is more than 55%
anticorrosion/antifreeze [freeze
protection to approx. -49°F (-45°C)], the
engine temperature will increase due to
the lower heat transfer capability of the
solution. Therefore, do not use more than
this amount of anticorrosion/antifreeze.If the coolant level is low, water and
MB 325.0 anticorrosion/antifreeze should
be used to bring it up to the proper level
(have cooling system checked for signs of
leakage). Please make sure the mixture is
in accordance with label instructions.
The water in the cooling system must meet
minimum requirements, which are usually
satisfied by normal drinking water. If you
are not sure about the water quality,
consult an authorized Mercedes-Benz
Center.