
241 Malfunction and warning messages
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index COOLANT TEMP. (coolant temperature)
1 Observe coolant temperature gauge, see page 86.
Check coolant level, see page 257.
This may indicate that the poly-V-belt has broken. Should this
c on diti on oc cur, the po ly-V-belt m ust be r ep lac ed befor e c ont inui ng
to operate the vehicle. Otherwise, the engine will overheat due to
an inoperative water pump which may result in damage to the
engine. 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.
During severe operating conditions and stop-and-go city
traf f ic, th e coolant temperature may rise close to th e red
marking.
The engine should not be operated with the coolant
temperature in the red zone. Doing so may cause
serious engine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Line 1 Line 2
COOLANT TEMP. VISIT WORKSHOP!
1
Wa r n i n g !
Driving when your engine is badly overheated 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 engine
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 it cools down.

254 Engine compartment
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Hood
Wa r n i n g !
To help prevent personal injury, stay clear of
moving parts wh en t he hood is open and th e engine
is running. Be sure the hood is properly closed
before driving. When closing hood, use extreme
caution not to catch hands or fingers.The radiator fan may continue to run for
approximately 30 seconds or even restart after the
engine has been turned off. Stay clear from fan
blades.
The engine is equipped with a transistorized
ignition system. Because of the high voltage it is
dangerous to touch any components (ignition coils,
spark plug sockets, diagnostic socket) of the
ignition system
• with the engine running,
• while starting the engine,
• if ignition is “on” and the engine is turned
manually.If you see flames, steam or smoke coming from the
engine compartment, or if the coolant temperature
gauge indicates that the engine is overheated, do
not open the hood. Move away from vehicle and do
not open the hood until the engine has cooled. If
necessary, call a fire department.

258 Engine compartment
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Adding coolant
If coola nt h as to be ad ded, a 50 / 50 m ixtu re of wa ter and
MB anticorrosion / antifreeze should be added.
The drain plugs for the cooling system are located on
the right side of the engine block and at the bottom of
the radiator.
Anticorrosion / antifreeze mixture, see page 322.
Wa r n i n g !
In order to avoid possible serious burns or injury:
• 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 indicates 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 cap approximately
1/2 turn to relieve excess pressure. If opened
immediately, scalding 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.

317 Fuels, coolants, lubricants etc. - capacities
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index Fuels, coolants, lubricants etc. – capacities
Veh icle c omponents and t heir respec tive lub rica nts mu st ma tch . T herefore u se only brands tested and rec omm end ed
by us. Please refer to the Factory Approved Service Products pamphlet, or inquire at your Mercedes-Benz Center.
Fuels, coolants, lubricants etc. Model Capacity
Engine with oil filter
(recommended engine oils)8.5 US qt (8.0 l)
Automatic transmission
(automatic transmission fluid)CLK 320
CLK 4308.5 US qt (8.0 l)
9.6 US qt (9.1 l)
Rear axle
(Hypoid gear oil SAE 90, 85 W 90)1. 4 U S q t (1. 3 l )
Power steering
(MB Power steering fluid)approx. 1.1 US qt (1.0 l)
Front wheel hubs
(high temperature roller bearing grease)approx. 2.1 oz (60 g) each
Brake system
(MB Brake fluid (DOT 4))approx. 0.5 US qt (0.5 l)
Cooling system
(MB Anticorrosion/antifreeze)CLK 320
CLK 430approx. 9.5 US qt (9.0 l)
a p p r o x . 11 . 7 U S q t ( 11 . 1 l )

318 Fuels, coolants, lubricants etc. - capacities
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
Windshield washer system
(MB Windshield washer concentrate “S”
1)approx. 7.4 US qt (7.0 l)
Fuel tank
including a reserve of
(Premium unleaded gasoline:
Posted Octane 91 (Avg. of 96 RON/86 MON))approx. 16.4 US gal (62.0 l)
approx. 2.1 US gal (8.0 l)
Air conditioner system
(R-134a refrigerant and special
PA C l u b r i c a n t (Never R-12))
1 Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing or MB Windshield Washer Concentrate “S” and
commercially available premixed windshield washer solvent/antifreeze for temperatures below freezing. Follow suggested mixing ratios, see
page 259.Fuels, coolants, lubricants etc. Model Capacity

322 Fuels, coolants, lubricants etc.
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car care Index
the engine temperature will increase due to the lower
h eat transfer ca pa bil ity of th e sol ution. Therefore, d o not
use more than this amount of anticorrosion/antifreeze.
If the coolant level is low, water and MB anticorrosion/
antifreeze should be used to bring it up to the proper
level (have cooling system checked for signs of leakage).
The water in the cooling system must meet minimum
requirements, which are usually satisfied by normal
drinking water. If your are not sure about the water
quality, consult your authorized Mercedes-Benz Center.
Anticorrosion/antifreeze
Your vehicle contains a number of aluminum parts. The
use of aluminum components in motor vehicle engines
necessitates that anticorrosion/antifreeze coolant used
in such e ng ines b e specif ica lly formul ated to protec t th e
aluminum parts. (Failure to use such anticorrosion/
antifreeze coolant will result in a significantly
shortened service life.)
Therefore the following product is strongly
recommended for use in your vehicle: Mercedes-Benz
Anticorrosion/antifreeze agent.Before the start of the winter season (or once a year in
the hot southern regions), you should have the
anticorrosion/antifreeze concentration checked. The
coolant is also regularly checked each time you bring
your vehicle to your authorized Mercedes-Benz Center
for service.
Anticorrosion/antifreeze quantity
Model Approx. freeze protection
-35°F
(-37°C)-49°F (
-45°C)
CLK 320 4.8 US qt
(4.5 l)5.3 US qt
(5.0 l)
CLK 430 5.9 US qt
(5.6 l)6.5 US qt
(6.1 l)

327 Index
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car careIndex Central locking system ................................................... 28
Automatic central locking ......................................... 37
Choosing global or selective mode ........................... 31
Electronic main key .................................................... 25
Electronic reserve key ................................................ 26
Locking and unlocking .............................................. 30
Mechanical keys .......................................................... 33
Remote control ............................................................ 28
Changing wheels ...........................................................266
CHECK ENGINE malfunction indicator lamp ............228
Check regularly and before a long trip ......................226
Checking engine oil level
Via engine oil level indicator ...................................112
Via oil dipstick ...........................................................256
Child restraint .............................................. 58, 63, 64, 74
Cleaning and care of the vehicle .................................302
Clock, setting .................................................................. 106
COMAND, radio and telephone ................................... 178
Combination switch .......................................................117
Consumer information ..................................................323
Control and operation of radio transmitters ............. 178
COOLANT (coolant level) -
malfunction and warning messages ......................240
Coolant level
Adding coolant ..........................................................258
Checking ....................................................................257COOLANT TEMP. (coolant temperature) -
malfunction and warning messages ......................241
Coolant temperature gauge ............................................ 86
Coolants ...........................................................................321
Anticorrosion/antifreeze quantity .........................321
Cruise control ................................................................. 214
Cup holder
Center console, front ................................................ 153
DDaytime running lamps ................................................ 115
Deep water
Driving instructions ................................................. 212
DISPLAY DEFECTIVE (engine control unit) -
malfunction and warning messages ..................... 235
DISPLAY DEFECTIVE (several systems) -
malfunction and warning messages ..................... 235
Display illumination ........................................................ 85
Doors .................................................................................. 34
Drinking and driving .................................................... 205
Drive sensibly - save fuel ............................................. 205
Driving instructions ..................................................... 205
Driving off ...................................................................... 207

331 Index
Te ch n ica l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hints Car careIndex
MMaintenance ................................................................... 179
Malfunction and indicator lamps
in the instrument cluster .........................................228
Malfunction and warning messages ...........................234
ABS-SYSTEM .............................................................237
BATTERY/ALTERNATOR ..........................................236
BRAKE ASSIST ..........................................................237
BRAKE FLUID ............................................................238
BRAKE LINING WEAR .............................................238
COOLANT (coolant level) .........................................240
COOLANT TEMP. (coolant temperature) ............... 241
DISPLAY DEFECTIVE (engine control unit) .........235
DISPLAY DEFECTIVE (several systems) ...............235
ELEC. STABIL. PROG. ...............................................245
ENGINE FAN ..............................................................239
ENGINE OIL LEVEL ..................................................244
LIGHT SENSOR .........................................................243
LIGHTING SYSTEM ...................................................242
PARKING BRAKE ......................................................239
REMOVE KEY ............................................................245
STEER. WHEEL ADJUST. .........................................243
TELE AID ....................................................................247
WASHER FLUID ........................................................246Malfunction message memory ....................................104
Manual operation of soft top ........................................ 291
Mechanical keys ............................................................... 33
Memory
Recalling ................................................................ 49, 79
Storing ........................................................................... 48
Mirror, exterior, adjusting ..............................................78
Mirror, exterior, rear view ..............................................78
Mirror, inside, rear view ................................................. 77
Multicontour seat ............................................................. 55
Multifunction display ...................................................... 88
Engine oil level indicator ...........................................92
FSS (Flexible service system) ................................... 92
Setting the audio volume .........................................108
Trip and main odometer ............................................ 92
Vehicle speed ............................................................... 92
Multifunction steering wheel .........................................88
NNavigation system - Multifunction display ................ 101
Night security illumination .......................................... 115