2008 MERCEDES-BENZ CLK550 engine

405 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
úVisit workshopThere may be a malfunction in the

fuel injection system

ignition system

exhaust system

fuel system
Have the measuring system checked
at an authorized Mercedes-Benz Cen-
ter.
B Top Up
Coolant
See Operator’s Man.The coolant level is too low.Add coolant (page 328).
If you have to add coolant frequently,
have the cooling system checked at
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 could 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.

406 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant
Stop vehicle,
turn engine off.The coolant is too hot.
Among other possible causes, the
poly-V-belt could be broken.Stop the vehicle in a safe location or
as soon as it is safe to do so.
Apply the parking brake (page 59).
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 in-
operative water pump which may re-
sult in damage to the engine. Contact
an authorized Mercedes-Benz Center.
If it is intact:
Wait for the message to disappear be-
fore restarting the engine.
Doing otherwise could result in seri-
ous engine damage that is not covered
by the Mercedes-Benz Limited War-
ranty.
(Continued on next page)

407 Practical hints
What to do if …?
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbolDisplay messagePossible cause/consequencePossible solution
•Observe the coolant temperature indicator in
the instrument cluster (
page 28).
If the temperature rises again:
Contact an authorized Mercedes-Benz
Center immediately.
•The cooling fan for the coolant is mal-
functioning.Observe the coolant temperature indicator in the
instrument cluster (
page 28).
Have the fan replaced as soon as possible.
Warning!G
Driving when your engine is 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 which can occur just by open-
ing 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.!The engine should not be operated with the
coolant temperature above 248°F (120°C). Do-
ing so may cause serious engine damage which
is not covered by the Mercedes-Benz Limited
Warranty.

409 Practical hints
What to do if …?
When the message Check oil level at
next refueling.
appears while the engine
is running and at operating temperature,
the engine oil level has dropped to
approximately the minimum level.When this occurs, the warning is at first in-
termittent and then remains on if the oil
level drops further.
Visually check for oil leaks. If there are no
obvious oil leaks, drive to the nearest ser-
vice station to refill the engine oil to the re-
quired level.
For information on approved engine oils,
refer to the Factory Approved Service
Products pamphlet (USA only) or contact
an authorized Mercedes-Benz Center.
Display symbolDisplay messagePossible cause/consequencePossible solution
:Check oil level
at next refueling
.
The engine oil level has dropped to a
critical level.Check the engine oil level
(
page 325) and add oil as required
(
page 327).
If you must add engine oil frequently,
have the engine checked for possible
leaks.
!Engine oil level warnings should not be ig-
nored. Extended driving with the symbol dis-
played could result in serious engine damage
that is not covered by the Mercedes-Benz Limit-
ed Warranty.

410 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
I Change
Key BatteriesThe SmartKey with KEYLESS-GO* batter-
ies are discharged.Change the batteries (page 441).
Key Detected
In VehicleA SmartKey with KEYLESS-GO* left in the
vehicle was recognized while locking the
vehicle from the outside.Take the SmartKey out of the vehicle.
Key
Not DetectedThe SmartKey with KEYLESS-GO* is mo-
mentarily not recognized.Change the position of the SmartKey
in the vehicle.
Operate the vehicle with the SmartKey
in the starter switch if necessary.
Key
Not DetectedThe SmartKey with KEYLESS-GO* is not
recognized while the engine is running be-
cause

the SmartKey is not in the vehicle

there is strong radio-frequency inter-
ference
Stop the vehicle as soon as it is safe to
do so.
Apply the parking brake (page 59).
Search for the SmartKey.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started
again after the engine has been stopped.
Please
get a new key.No additional code available for SmartKey
or SmartKey with KEYLESS-GO*Contact an authorized Mercedes-Benz
Center as soon as possible.

411 Practical hints
What to do if …?
Display symbolDisplay messagePossible cause/consequencePossible solution
I Please don’t
forget your keyThis display appears (for a maximum of
60 seconds) if the driver’s door is opened
with the engine shut off and no SmartKey in
the starter switch.
Message is only a reminder.Insert SmartKey in the starter switch.
Take the SmartKey with
KEYLESS-GO* with you when leaving
the vehicle.
Remove KeyYou have forgotten to remove the SmartKey.Remove the SmartKey from the start-
er switch.
. Active Headlamps
Auxiliary Bulb OnThe active headlamps are malfunctioning. An-
other light is being used.Contact an authorized Mercedes-Benz
Center as soon as possible.
Active Headlamps
InoperativeThe Bi-Xenon cornering lamps system is mal-
functioning.Contact an authorized Mercedes-Benz
Center as soon as possible.
AUTO-Light
InoperativeThe light sensor is malfunctioning. The head-
lamps switch on automatically.Contact an authorized Mercedes-Benz
Center as soon as possible.
To switch off the headlamps:
In the control system, set lamp opera-
tion to manual mode (
page 162).
Switch off the headlamps using the
exterior lamp switch (
page 129).
3rd
Brake LampThe high mounted brake lamp is malfunction-
ing. This message will only appear if a critical
number of LEDs have stopped working.Contact an authorized Mercedes-Benz
Center as soon as possible.

430 Practical hints
Opening/closing in an emergency (Cabriolet)
Operating roll bars manually
Releasing roll bars manually
If the roll bar system is malfunctioning, you
can release the roll bars manually.Close the soft top (page 261).
Open the trunk (page 110).
Fold back the luggage cover
(
page 264).
Take hex wrench out of its storage
location in the storage well casing
(
page 422).
1Perforation
Push hex wrench through
perforation1 in trim of rear wall in
trunk.
2Hex wrench
Warning!G
If the yellow roll bar warning lamp in
the clock does not go out after starting the
engine, or if it comes on while driving, then
the roll bar system is not operating properly
and may not activate in an accident. In this
case, raise the roll bars manually before
continuing to drive.
For safety reasons drive only with the roll
bars raised until the malfunction is repaired.
Have your vehicle checked at an authorized
Mercedes-Benz Center.
iWith the roll bars released, the soft top can-
not be operated using the soft top switch and the
rear head restraints cannot be lowered using the
rear head restraint lowering switch.
Warning!G
Make sure no one is located in the roll bar’s
path of motion while the next steps are be-
ing carried out.
When the roll bar is manually released, the
rear head restraints and the roll bar under-
neath shoot up almost instantaneously.

432 Practical hints
Opening/closing in an emergency (Cabriolet)
Soft top emergency operation
If the soft top cannot be automatically
closed, check the following:

Is the luggage cover engaged in place
(
page 264)?

Have the roll bars been released? If so,
lower the roll bars manually
(
page 431).

Is the trunk lid closed (page 112)?

Is there sufficient on-board voltage?
Start the engine if necessary.
These messages will also appear in the
multifunction display (
page 420).
If automatic operation still does not func-
tion properly, you can close the soft top
manually.
This procedure should be performed with
great care by two persons.
Engage parking brake.
Lower the side windows.
Lower rear head restraints
(
page 123).
For safety reasons, remove SmartKey
from starter switch.
Open the trunk.
Remove the trunk floor cover.
Take the two straps for soft top emer-
gency operation out of vehicle tool kit
(
page 422).
Take hex wrench out of its storage
location in the storage well casing
(
page 422).
Open the left side trim panel in the
trunk.
!Manually closing the soft top is a complicat-
ed and technically demanding procedure. Close
the soft top manually in emergency cases only.
Otherwise, visit an authorized Mercedes-Benz
Center. Please read the instructions fully before
beginning operation and only undertake it with
another person and if you feel fully capable of
performing the tasks involved.
Warning!G

It is important that a second person
helps you. Otherwise, you could become
trapped or injured.

Remove any wristwatches or jewelry
such as rings or bracelets. Otherwise,
they could get caught in the vehicle
mechanism, causing personal injury to
yourself or damage to the vehicle.

Always use the grips provided as indi-
cated. Otherwise you could injure your-
self.
iIf the rear head restraints cannot be lowered
using the rear head restraint lowering switch, the
roll bars may have been released. For more infor-
mation, see “Operating roll bars manually”
(
page 430).