2004 MERCEDES-BENZ CLK320 COUPE check engine

327 Practical hints
What to do if …?
When the message
Add 1 qt. engine oil
when next refueling
(Canada:
1 liter
)
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 will first
come on intermittently and then stay on if
the oil level drops further.
Visually check for oil leaks. If no obvious oil
leaks are noted, drive to the nearest ser-
vice station where the engine oil should be
topped to the required level with an ap-
proved oil.
Display symbol
Display message
Possible cause
Possible solution
:
Engine oil
Visit workshop!
It may be that there is water in the engine
oil.

Have the engine oil checked.
Engine oil level
Visit workshop!
The engine oil has dropped to a critical
level.

Check the engine oil level
(page 283) and add oil as required
(page 285).

If you must add engine oil frequently,
have the engine checked for possible
leaks.
The measuring system is malfunctioning.

Have the measuring system checked
by an authorized Mercedes-Benz
Center.!The engine oil level warnings should
not be ignored. Extended driving with
the symbol displayed could result in
serious engine damage that is not
covered by the Mercedes-Benz Limited
Warranty.

328 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
A
Reserve fuel
The fuel level has dropped below the re-
serve mark.

Refuel at the next gas station
(page 278).
Y
Hood open!
You are driving with the hood open.

Close the hood (
page 282).
I
Remove key
You have forgotten to remove the
SmartKey.

Remove the SmartKey from the start-
er switch.
Replace key!
No additional code available for SmartKey
or SmartKey with KEYLESS-GO*

Visit an authorized Mercedes-Benz
Center as soon as possible.
Key
Check battery!
The SmartKey with KEYLESS-GO* batter-
ies are discharged.

Change the batteries (
page 345).
Key
not recognized!
The 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.

Search for the SmartKey.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started
again after the engine has been stopped.
The 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.

329 Practical hints
What to do if …?
Display symbol
Display message
Possible cause
Possible solution
I
Key recognized
in vehicle
A SmartKey with KEYLESS-GO* left in the
vehicle was recognized while locking the
vehicle from the outside.

Take the SmartKey out of the vehicle.
Keyless Go
Check system
The KEYLESS-GO* system is malfunction-
ing.

Visit an authorized Mercedes-Benz
Center as soon as possible.
Key
do not forget key
This 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.
.
3rd stop lamp
The high mounted brake lamp is malfunc-
tioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.
Back- up lamp, left
The left backup lamp is malfunctioning.

Replace the bulb as soon as possible.
Back- up lamp, right
The right backup lamp is malfunctioning.

Replace the bulb as soon as possible.
Display defective!
Visit workshop!
The display for the lamps or the system is
malfunctioning.

Visit an authorized Mercedes-Benz
Center as soon as possible.
Front foglamp, left
The left front fog lamp is malfunctioning.

Replace the bulb as soon as possible.
Front foglamp, right
The right front fog lamp is malfunctioning.

Replace the bulb as soon as possible.

363 Practical hints
Battery
Battery
The battery is located on the right side of
the engine compartment.
Removal of filter box:
Release the three clamps1.

Remove filter box.
Installation of filter box:

Insert filter box properly.

Secure it with the three clamps1.
Warning!
G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries,
see “Battery” (
page 288).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Service Booklet for mainte-
nance intervals or contact your autho-
rized Mercedes-Benz Center for further
information.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.

366 Practical hintsJump starting
Jump starting
If the battery is discharged, the engine can
be started with jumper cables and the bat-
tery of another vehicle. Observe the follow-
ing:

Jump starting should only be performed
when the engine and catalytic convert-
er are cold.


Do not start the engine if the battery is
frozen. Let the battery thaw out first.


Only jump start from batteries with the
same voltage rating (12 V). Jump start-
ing with a more powerful battery could
damage the vehicle’s electrical system,
which will not be covered by the
Mercedes-Benz Limited Warranty.


Only use jumper cables with sufficient
cross-section and insulated terminal
clamps.


Always make sure the jumper cables
are not on or near pulleys, fans or other
parts that move when an engine is
started or running.
Warning!
G
Failure to follow these directions will cause
damage to the electronic components, and
can lead to a battery explosion and severe
injury or death.
Never lean over batteries while connecting
or jump starting, you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water, and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and very explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
Attempting to jump start a frozen battery
can result in it exploding, causing personal
injury.
Read all instructions before proceeding.
!Avoid repeated and lengthy starting at-
tempts.
Do not attempt to start the engine us-
ing a battery quick charge unit.
If the engine does not run after several
unsuccessful starting attempts, have it
checked at the nearest authorized
Mercedes-Benz Center.
Excessive unburned fuel generated by
repeated failed starting attempts may
damage the catalytic converter and
may present a fire risk.
Make sure the jumper cables do not
have loose or missing insulation.
Make sure the cable clamps do not
touch any other metal part while the
other end is still attached to a battery.

367 Practical hints
Jump starting
The battery is located on the right side of
the engine compartment. For jump start-
ing use the terminals in front of the bat-
tery.
Make sure the two vehicles do not
touch.

Turn off all electrical consumers.

Apply parking brake.

Shift gear selector lever to positionP.

Open the hood.1Positive terminal of charged battery
2Positive under hood terminal in front of
discharged battery
3Negative under hood terminal in front
of discharged battery
4Negative terminal of charged battery

Connect the positive terminal1 of the
charged battery with the positive under
hood terminal 2 in front of the dis-
charged battery with the jumper cable.
Clamp cable to charged battery1
first.

Start engine of the vehicle with the
charged battery and run at idle speed.

Connect the negative terminal4 of
the charged battery with the negative
under hood terminal 3 in front of the
discharged battery with the jumper ca-
ble. Clamp cable to charged battery4
first.

Start the engine of the disabled vehi-
cle.
You can now turn on the electrical con-
sumers. Do not turn on the lights under
any circumstances.

Remove the jumper cables first from
the negative terminals3 and4 and
then from the positive terminals1
and2.
You can now turn on the lights.

Have the battery checked at the near-
est authorized Mercedes-Benz Center.
Warning!
G
Keep flames or sparks away from battery.
Do not smoke.
Observe all safety instructions and precau-
tions when handling automotive batteries
(page 288).
!Never invert the terminal connections.
!Do not tow-start the vehicle.

390 Technical dataFuels, coolants, lubricants, etc.Engine oils
Engine oils are specifically tested for their
suitability in our engines. Therefore, only
use engine oils approved by
Mercedes-Benz. Information on approved
engine oils is available in the Factory Ap-
proved Service Products pamphlet, or at
your authorized Mercedes-Benz Center.Please follow FSS recommendations for
scheduled oil changes. Failure to do so
could result in engine damage not covered
by the Mercedes-Benz Limited Warranty.
Engine oil additives
Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from
blending oil additives are not covered by
the Mercedes-Benz Limited Warranty.Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air condition-
ing system.Never use R-12 (CFC) or mineral-based lu-
bricating oil. Otherwise damage to the
system will occur.
Brake fluid
During vehicle operation, the boiling point
of the brake fluid is continuously reduced
through the absorption of moisture from
the atmosphere. Under extremely strenu-
ous operating conditions, this moisture
content can lead to the formation of bub-
bles in the system, thus reducing the sys-
tem’s efficiency.
Therefore, the brake fluid must be re-
placed every two years, preferably in the
spring.
Only brake fluid approved by
Mercedes-Benz is recommended. Your au-
thorized Mercedes-Benz Center will pro-
vide you with additional information.
!Always check the oil filler cap
(page 285) for important information
pertaining to the engine oil needing to
meet a specific Mercedes-Benz specifi-
cation (e.g. MB 229.5). If such informa-
tion is printed on the oil filler cap, only
use an engine oil from the list of ap-
proved engine oils in the Factory Ap-
proved Service Products pamphlet that
meets the specification indicated on
the oil filler cap.
Using engine oils of other specification
may cause the FSS to incorrectly deter-
mine the next service interval and will
result in engine damage not covered by
the Mercedes-Benz Limited Warranty.

392 Technical dataFuels, coolants, lubricants, etc.Damage or malfunctions resulting from
poor fuel quality or from blending specific
fuel additives are not covered by the
Mercedes-Benz Limited Warranty.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 corro-
sion 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 approximately 266°F
(130°C).
The coolant solution must be used year
round to provide the necessary corrosion
protection and increase boil-over protec-
tion. Refer to Service Booklet for replace-
ment interval.
Coolant system design and coolant used
stipulate the replacement interval. The
replacement interval published in the
Service Booklet is only applicable if
MB 325.0 anticorrosion/antifreeze solu-
tion or other Mercedes-Benz approved
products of equal specification (see Facto-
ry Approved Service Products pamphlet)
are used to renew the coolant concentra-
tion or bring it back up to the proper level.To provide important corrosion protection,
the solution must be at least 45% anticor-
rosion/antifreeze (equivalent to freeze
protection to approx. -22°F [-30°C]). If you
use a solution that is more than 55% anti-
corrosion/antifreeze (freeze protection to
approx. -49°F [-45°C]), the engine temper-
ature will increase due to the lower heat
transfer capability of the solution. There-
fore, do 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 cool-
ing system checked for signs of leakage).
Please make sure the mixture is in accor-
dance 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, con-
sult your authorized Mercedes-Benz
Center.