2005 MERCEDES-BENZ CLK500 CABRIOLET cooling

195 Controls in detail
Automatic climate control (CLK 500/CLK 55 AMG)
Adjusting automatically
Press buttonU (
page 191).
The indicator lamp on the button
comes on.
The air volume is controlled automati-
cally for the entire vehicle, and the air
distribution is controlled automatically
for each separate half of the vehicle.
Defrosting
Activating
Press buttonP or0
(page 191).
The indicator lamp on the button
comes on.
The air conditioning switches automatical-
ly to the following functions:


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 or0
(page 191) again.
The indicator lamp on the button goes
out. Defrosting is turned off.
The previous settings are once again in
effect.
Maximum cooling MAXCOOL
If the left and right air distribution controls
as well as the airflow volume control are
set toU (
page 191) 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 soft top are closed).
Air recirculation mode
Switch to air recirculation mode to prevent
unpleasant odors from entering the vehicle
from the outside. This setting cuts off the
intake of outside air and recirculates the
air in the passenger compartment.
iThese settings should only be selected
for a short time.
Warning!
G
When the outside temperature is below
41°F (5°C), only switch to air recirculation
mode for short periods to prevent window
fogging.
Window fogging may impair visibility and
endanger you and others.

198 Controls in detailAutomatic climate control (CLK 500/CLK 55 AMG)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
vehicle will then no longer be cooled or
dehumidified.
Automatic climate control panel
design A

Press button° (
page 191).
The indicator lamp on the button
comes on.
The cooling function switches off after
a short delay.
Automatic climate control panel
design B

Press button2(
page 191).
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.
Automatic climate control panel
design A

Press button°(
page 191) again.
The indicator lamp on the button goes
out.
The cooling function is switched on.
Automatic climate control panel
design B

Press button2(
page 191)
again.
The indicator lamp on the button
comes on.
The cooling function is switched 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.

204 Controls in detailAudio systemButton 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 position 1 or 2.

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 position 1 or 2.
or

Press M button.Switching off

Remove SmartKey from starter switch.
or

Press M button.
!Do not press directly in the display
face. Otherwise, the display will be
damaged.
iIf the radio is switched on without the
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 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.

310 OperationEngine compartmentCoolant
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
compartment.
1Coolant expansion tank
2Cap

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

Continue turning the cap2 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 cap2.
More information on coolant can be found
in the “Technical data” section
(
page 458).
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 the coolant temperature is
above 158°F (70°C). Allow the coolant
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.

357 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
•
The red coolant warning lamp
comes on when the engine is
running.
There is insufficient coolant in the reservoir.

Add coolant to prevent engine from
overheating (
page 310).
If this warning lamp comes on frequently,
there is a leak in the cooling system.

Have the cooling system checked.
If the coolant level is correct, the electric ra-
diator fan may be broken.

If the coolant temperature is below
257 °F (125 °C), you can continue
driving to the nearest authorized
Mercedes-Benz Center.

Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.
•
The red coolant warning lamp
comes on while driving and you
hear a warning sound.
The coolant temperature has exceeded
257 °F (125 °C).

Stop as soon as possible and allow
the engine and coolant to cool down.
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have
leaked into the engine compartment to
catch fire. You could be seriously burned.
Steam from an overheated engine can cause
serious burns and can occur just by opening
the hood. Stay away from the engine if you
see or hear steam coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.

376 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
ú
Visit workshop!
There may be a malfunction in the

fuel injection system


ignition system


exhaust system


fuel system

Have the measuring system checked
by an authorized Mercedes-Benz Cen-
ter.
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 310).

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.

378 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
•
Coolant
Stop, engine off!
The poly-V-belt could be broken.

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an in-
operative water pump which may re-
sult in damage to the engine. Notify an
authorized Mercedes-Benz Center.
If it is intact:

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

Drive immediately to the nearest au-
thorized Mercedes-Benz Center.
Coolant
Visit workshop
!
The cooling fan for the coolant is malfunc-
tioning.

Observe the coolant temperature dis-
play.

Have the fan replaced as soon as pos-
sible.

454 Technical dataFuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants, etc.
Cooling system
CLK 320
CLK 500
CLK 55 AMG
approx. 10.7 US qt (10.0 l)
approx. 12.8 US qt (12.0 l)
approx. 12.8 US qt (12.0 l)
MB 325.0 Anticorrosion/Antifreeze
Agent
Fuel tank
including a reserve of
CLK 320
CLK 500
CLK 55 AMG
16.35 US gal (62.0 l)
2.11 US gal (8.0 l)
2.11 US gal (8.0 l)
2.64 US gal (10.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON / 86 MON)
Air conditioning system
R-134a refrigerant and special PAG lu-
bricant oil (never R-12)
Windshield washer and
headlamp cleaning system*
6.4 US qt (6.0 l)
MB Windshield Washer Concentrate
1
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 460).