Cooling system MERCEDES-BENZ C240 2003 W203 Owner's Manual

Contents
Automatic transmission* ................... 138
One-touch gearshifting................. 139
Gear ranges ................................. 140
Gear selector lever position ......... 141
Program mode selector switch..... 142
Accelerator position ..................... 143
Emergency operation
(Limp Home Mode) ...................... 143
Good visibility .................................... 144
Rear view mirror........................... 144
Headlamp cleaning system* ........ 146
Sun visors .................................... 146
Rear window sunshade* .............. 147
Climate control .................................. 148
Setting the temperature ............... 150
Adjusting air distribution and
volume ......................................... 151
Defrosting .................................... 151
Air recirculation mode.................. 152
Rear window defroster ................. 153
Deactivating the climate control
system ......................................... 153
Air conditioning ............................ 154
Ventilated storage compartment . 155
Rear passenger compartment
adjustable air vents ...................... 155Automatic climate control* ................ 156
Setting the temperature................ 158
Adjusting air distribution............... 159
Adjusting air volume ..................... 159
Maximum cooling MAXCOOL ........ 160
Defrosting ..................................... 160
Air recirculation mode .................. 160
Charcoal filter ............................... 161
Rear window defroster .................. 162
Air conditioning............................. 163
Residual heat and ventilation* ...... 163
Rear passenger compartment
adjustable air vents....................... 164
Audio system ...................................... 165
Audio and telephone, operation .... 165
Operating safety ........................... 165
Operating and display elements.... 166
Button and soft key operation....... 168
Operation ...................................... 168
Radio mode................................... 171
Cassette mode.............................. 174
CD changer* operating mode ....... 178
Telephone* operation ................... 182Power windows .................................. 187
Opening and closing the windows 187
Synchronizing power windows ...... 189
Sliding/pop-up roof*.......................... 190
Opening and closing the
sliding/pop-up roof....................... 190
Synchronizing the
sliding / pop-up roof ...................... 192
Driving systems .................................. 193
Cruise control ............................... 193
Loading .............................................. 196
Roof rack* .................................... 196
Ski sack* ...................................... 196
Split rear bench seat*................... 199
Loading instructions ..................... 202
Useful features ................................... 203
Interior storage spaces ................. 203
Ashtrays........................................ 207
Cigarette lighter ............................ 208
Telephone* ................................... 208
Tele Aid* ....................................... 209
Garage door opener ...................... 217

50 Getting startedDrivingThe coolant temperature is over 248°F
(120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle as soon as possible
and turn off the engine. Allow engine
and coolant to cool.

Check the coolant level and add cool-
ant if necessary (
page 238).In case of accident
If the vehicle is leaking gasoline:

Do not start the engine under any cir-
cumstances.

Notify local fire and/or police authori-
ties.
If the extent of the damage cannot be de-
termined:

Notify an authorized Mercedes-Benz
Center.
If no damage can be determined on the


major assemblies


fuel system


engine mount:

Start the engine in the usual manner.

150 Controls in detailClimate controlThe climate control is operational whenev-
er the engine is running. You can operate
the climate control system in either the au-
tomatic or manual mode. The system cools
or heats the interior depending on the se-
lected interior temperature and the cur-
rent outside temperature.
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 theAC
OFF
mode is selected
(
page 154).
Setting the temperature
Use the temperature controls2 and3
(page 149) 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).
Increasing

Turn the control slightly to the right.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing

Turn the control slightly to the left.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
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.iIf the vehicle interior is hot, ventilate
the interior before driving off.
Keep the air intake grille in front of the
windshield free of snow and debris.
Do not obstruct air flow by placing ob-
jects on the air flow-through exhaust
slots below the rear window.

154 Controls in detailClimate controlAir conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.
Deactivating
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.
Press buttonAC
OFF
(page 149).
The indicator lamp on the
buttonAC
OFF
lights up.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.

PressAC
OFF
again (
page 149).
The indicator lamp on the
buttonAC
OFF
goes out.
The air conditioning uses the
refrigerant R134a. This refrigerant is free
of CFC’s 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.
!If the air conditioning cannot be turned
on again, this indicates that the air con-
ditioning is losing refrigerant. The com-
pressor has turned itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Center.

155 Controls in detail
Climate control
Ventilated storage compartment
The front center console storage compart-
ment has its own air vent that allows for
cooling ventilation when the automatic cli-
mate control system is activated.
1LeverOpening the air vent

Raise lever1.
Closing the air vent

Lower lever1.Rear passenger compartment adjust-
able air vents
1Center air vent, left
2Thumbwheel for air volume control for
center air vents
3Center air vent, right
To open center air vents:
Turn thumbwheel2 upward.
iYou should keep this air vent closed
when outside temperatures are low.
iThe compartment can get very warm
due to its confined space. When storing
heat sensitive objects in the compart-
ment, close the air vent while heating
the passenger compartment.!Do not obstruct the air vent in the
storage compartment.
iThe temperature at the air vents for the
rear passenger compartment1 and3
is the same as at the dashboard center
air vents.

157 Controls in detail
Automatic climate control*
Automatic climate control panel
Item
1
Air volume control for left center air
vent
2
Left center air vent, adjustable
3
Thumbwheel for adding outside air
4
Right center air vent, adjustable
5
Air volume control for right center
air vent
6
Air volume control for side air vent
7
Side air vent, adjustable
8
Side defroster vent, fixed
9
Automatic climate control paneliFor draft-free ventilation, move the slid-
ers for the center air vents to the mid-
dle position.
Item
1
Temperature control, left, raising
2
Left-side air distribution control
(automatic or manual operation)
3
Activated charcoal filter
4
Display
5
Right-side air distribution control
(automatic or manual operation)
6
Temperature control, right, raising
7
Temperature control, right,
lowering
8
Rear window defroster
9
AC cooling on/off (AC
OFF
)
Residual heat/ventilation
10
Air volume control
11
Automatic climate control on/off
(complete system)
12
Air recirculation
13
Defrosting
14
Temperature control, left, lowering

158 Controls in detailAutomatic climate control*The automatic climate control is operation-
al whenever the engine is running. You can
operate the climate control system in ei-
ther the automatic or manual mode. The
system cools or heats the interior depend-
ing on the selected interior temperature
and the current outside temperature.
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 theAC
OFF
mode is selected
(
page 149).
Setting the temperature
Use temperature controls1 and14 for the
left side or6 and7 for the right side to
separately adjust the air temperature on
each side of the passenger compartment.
You should raise or lower the temperature
setting in small increments, preferably
starting at 72°F (22°C).Increasing

Push temperature control1 and/or6.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
Decreasing

Push temperature control7
and/or14.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
Adding outside air

Turn thumbwheel3 in dashboard
(page 156) to increase airflow of out-
side air through air vents for center, left
and right sides and rear passenger
compartment.
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.
iIf the vehicle interior is hot, ventilate
the interior before driving off.
Keep the air intake grille in front of the
windshield free of snow and debris.
Do not obstruct air flow by placing ob-
jects on the air flow-through exhaust
slots below the rear window.iWhen operating the climate control
system in automatic mode, you will
only rarely need to adjust the tempera-
ture, air volume and air distribution.

163 Controls in detail
Automatic climate control*
Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.
Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the vehi-
cle will then no longer be cooled or dehu-
midified.
Press buttonAC
OFF
.
The indicator lamp on the
buttonAC
OFF
lights up.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.

PressAC
OFF
again.
The indicator lamp on the
buttonACOFF
goes out.
The air conditioning uses the
refrigerant R134a. This refrigerant is free
of CFCs which are harmful to the ozone
layer.
Residual heat and ventilation*
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.
Activating
Turn the key in the starter switch to
position1 o r r e m o v e i t f r o m t h e s t a r t e r
switch.

Press button
T
.
The indicator lamp on button
T

comes on.
Deactivating

Press button
T
.
The indicator lamp on button
T

goes off.
iCondensation may drip out from under-
neath 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 con-
ditioning is losing refrigerant. The com-
pressor has turned itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Center.

239 Operation
Engine compartment
1Coolant expansion tank
Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease 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.
More information on coolant can be found
in the “Technical data” section
(
page 336).
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 engine temperature is
above 194°F (90°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 approx-
imately
1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.


Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.

266 Practical hintsWhat to do if …Display
Possible cause
Suggested solution
B
COOLANT
CHECK LEVEL!
The coolant level is too low.

Add coolant (
page 238).

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 en-
gine damage.