2003 MERCEDES-BENZ CLK500 COUPE check engine

254 OperationEngine compartment
Closing
Let the hood drop from a height of ap-
proximately 1 ft (30 cm).
The hood will lock audibly.

Check to make sure that the hood is
fully closed.
If you can raise the hood at a point
above the headlamps, then it is not
properly closed. Open it again and let it
drop with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when

the vehicle is new


the vehicle is driven frequently at high-
er engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Checking engine oil level
When checking the oil level the vehicle
must


be parked on level ground


be at normal operating temperature


have been stationary for at least five
minutes with the engine turned off
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from the vehicle and do not open the
hood until the engine has cooled. If neces-
sary, call the fire department.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components (ig-
nition 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
Warning!
G
Be careful that you do not close the hood on
anyone.

255 Operation
Engine compartment
You can check the engine oil level on the
multifunction display.
Turn the key in the starter switch to
position2.
The standard display (
page 114) should
appear in the multifunction display.

Press button
k
or
j
on the
steering wheel until the following mes-
sage is seen in the multifunction dis-
play:
Engine oil level Measuring now!
Measurement correct only if veh.
level
One of the following messages will sub-
sequently appear in the indicator:

Engine oil level ok


Add 1.0 qt. to reach max. oil
level!(Canada:
1.0 liter
)


Add 1.5 qts. to reach max. oil
level!(Canada:
1.5 liters
)


Add 2.0 qts. to reach max. oil
level!(Canada:
2.0 liters
)

If necessary, add engine oil.Adding engine oil
1Filler neck

Unscrew the cap from filler neck 1. Be
careful not to overfill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.

256 OperationEngine compartment
Screw the cap back on the filler neck.
Other display messages
If there is excessive engine oil with the en-
gine at normal operating temperature, the
following message will appear:
Engine oil level Reduce oil level!
Have excess oil siphoned.
If the key is not turned to position 2 in the
starter switch:
Turn on ignition to see engine oil
level!
Switch on the ignition.If you see the message:
Observe waiting time
Wait five minutes before repeating
check procedure.
If you see the message:
Engine oil level Not when engine on! 
Turn off the engine. If engine is at nor-
mal operating temperature, wait five
minutes before checking oil. If the en-
gine is not yet at normal operating tem-
perature, you must wait 30 minutes
before checking oil.
See “Practical hints” (
page 294) if the
engine oil level indicator lights up in the
display while the engine is running.More information on engine oil can be
found in the “Technical data”
(
page 353).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Center
check the automatic transmission.Coolant
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 compart-
ment.
!Excessive oil must be siphoned or
drained off. It could cause damage to
the engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.
iIf you want to interrupt the checking
procedure, press the
k
or
j
but-
ton on the multifunction steering
wheel.

258 OperationEngine compartmentBattery
Your vehicle’s battery is located on the
right side of the engine compartment.
The battery should always be sufficiently
charged in order to achieve its rated ser-
vice life.
If you use your vehicle mostly for short dis-
tance trips, you will need to have the bat-
tery charge checked more frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Center about
steps you need to observe.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
G
Observe all safety instructions
and precautions when handling
automotive batteries.
A
Risk of explosion
D
Keep flames or sparks away
from battery. Do not smoke.
B
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
In case it does, immediately
flush affected area with clear
water and seek medical help if
necessary.
E
Wear eye protection.
C
Keep children away.
F
Follow the instructions in this
Operator's Manual.

264 OperationWinter driving
Winter drivingBefore the onset of winter have your vehi-
cle winterized at an authorized
Mercedes-Benz Center. This service in-
cludes:

Check of anticorrosion and antifreeze
concentration.


Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a pre-mixed windshield washer
solvent / antifreeze which is formulated
for below freezing temperatures
(page 357).


Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to ensure
that the engine can be started even at
low ambient temperatures.


Tire change. We recommend M+S rat-
ed radial-ply tires on all four wheels for
the winter season.
Winter tires
Always use winter tires at temperatures
below 39°F (4°C) and whenever wintry
road conditions prevail. Use of winter tires
is the only way to achieve the maximum ef-
fectiveness of the ABS and the ESP in win-
ter operation.
For safe handling, ensure that all mounted
winter tires are of the same make and have
the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your ve-
hicle, you must place a notice to this effect
where it will be seen by the driver. Such no-
tices are available from your tire dealer or
from any authorized Mercedes-Benz
Center.Warning!
G
Winter tires with a tread depth under 0.16 in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Warning!
G
If you use your spare tire* when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Center.

279 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
;
(except Canada)
3
(Canada only)
You are driving with the parking brake set.

Release the parking brake
(page 45).
The red brake warning lamp
lights up while driving and you
hear a warning sound.The red brake warning lamp
lights up while driving.
There is insufficient brake fluid in the reser-
voir.

Risk of accident! Carefully stop the
vehicle and notify an authorized
Mercedes-Benz Center. Do not add
brake fluid! This will not solve the
problem.
Warning!
G
Driving with the brake warning lamp illumi-
nated can result in an accident. Have your
brake system checked immediately if the
brake warning lamp stays on. Don’t add
brake fluid before checking the brake
system.
Overfilling the brake fluid reservoir can re-
sult in spilling brake fluid on hot engine
parts and the brake fluid catching fire. You
can be seriously burned.
!If you find that the brake fluid in the
brake fluid reservoir has fallen to the
minimum mark or below, have the
brake system checked for brake pad
thickness and leaks.

280 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
?
The yellow “CHECK ENGINE”
malfunction indicator lamp
comes on while driving.
There is a malfunction in:

The fuel management system


The ignition system


The emission control system


Systems which impact emissions
Such malfunctions may result in excessive
emissions values and may switch the engine
to its Limp-Home Mode (emergency opera-
tion).

Have the vehicle checked as soon as
possible by an authorized
Mercedes-Benz Center.
An on-board diagnostic connector is
used by the service station to link the
vehicle to the shop diagnostics system.
It allows the accurate identification of
system malfunctions through the read-
out of diagnostic trouble codes. It is lo-
cated in the front left area of the
footwell next to the parking brake pedal.
The fuel cap is not closed tightly.

Check the fuel cap.
Your gas tank is empty.

After refuelling, start the engine three or
four times in succession.
The Limp-Home mode is canceled. You do
not need to have your vehicle checked.
<
The red seat belt warning lamp
blinks for a brief period after
starting the engine.
The warning lamp reminds you to fasten seat
belts.

Fasten your seat belt.
A
The yellow fuel tank reserve
warning lamp lights up while
driving.
The fuel level has gone below the reserve
mark.

Refuel at the next gas station
(page 251).

281 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
•
The red coolant warning lamp
lights up when the engine is run-
ning.
There is insufficient coolant in the reservoir.

Add coolant to prevent engine from
overheating (
page 256).
If this warning lamp lights up 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
lights up 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 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.