check engine MERCEDES-BENZ SLK CLASS 2003 User Guide

176 OperationEngine compartmentTransmission 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 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.
SLK 230 Kompressor1Coolant expansion tank
2Float in the filler neck
Using a rag, turn the cap to the left to
the first detent position. Allow any ex-
cess pressure to escape.

Continue turning the cap to the left and
remove it.
The coolant level is correct if float2
can be seen at the top through the filler
neck.
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 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 the cap approx-
imately ½ 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.


178 OperationEngine compartmentBattery
Your vehicle’s battery is located in the en-
gine 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.
Observe all safety instructions
and precautions when handling
automotive batteries.Risk of explosionKeep flames or sparks away
from battery. Do not smoke.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.
Wear eye protection.Keep children away.Follow the instructions in this
Operator's Manual.

183 Operation
Winter driving
Winter driving
Before the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Center. This service
includes:

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 premixed windshield washer
solvent / antifreeze which is formulated
for below freezing temperatures
(page 275).


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
rated 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 ESP in winter
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.

195 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
¿
The yellow BAS/ESP malfunction
indicator lamp comes on while
driving.
The ESP is deactivated because of an inter-
rupted power supply. The ABS may still be
operational.

With vehicle stationary and the engine
running, turn the steering wheel com-
pletely to the left and then to the right
to synchronize the ESP.
The BAS has detected a malfunction and
switched off. The brake system is still func-
tioning normally but without the BAS avail-
able.

Continue driving with added caution.

Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
Failure to follow these instructions in-
creases the risk of accident.
The charging voltage has fallen below
10 volts and the BAS has switched off.

When the voltage is above this value
again, the BAS is operational again.

If necessary, have the alternator and
battery checked.

196 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
-
The yellow ABS malfunction indi-
cator lamp and warning comes
on while driving.
The ABS has detected a malfunction and has
switched off. The BAS and ESP are also
switched off. Both indicator lamps come on
with the engine running.
The brake system is still functioning normally
but without the ABS available.

Continue driving with added caution.
Wheels will lock during hard braking
reducing steering capability.

Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
Failure to follow these instructions in-
creases the risk of an accident.
The charging voltage has fallen below
10 volts and the ABS has switched off.

When the voltage is above this value
again, the ABS is operational again.

If necessary, have the alternator and
battery checked.

198 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
3
(Canada only)
;
(except Canada)The red brake warning lamp
lights up while driving and you
hear a warning sound.
You are driving with the parking brake set.

Release the parking brake
(page 42).
3
(Canada only)
;
(except Canada)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 sys-
tem.
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.

199 Practical hints
What 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 affect emissions
Such malfunctions may result in excessive
emissions values and may switch the engine
to its limp-home (emergency operation)
mode.

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 sys-
tem. It allows the accurate identifica-
tion of system malfunctions through
the readout of diagnostic trouble
codes. It is located in the passenger
compartment near the engine hood
release.
The fuel cap is not closed tight.

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.

200 Practical hintsWhat to do if …?When the low engine oil level warning lamp
does not go out after starting the engine,
or comes on while the engine is running
and at operating temperature, the engine
oil level has dropped to approximately the
minimum mark on the dipstick.When this occurs, the warning lamp will
first come on intermittently and then stay
on if the oil level drops further.
If no oil leaks are noted, continue to drive
to the nearest service station where the
engine oil should be topped to the “full”
mark on the dipstick with an approved oil.Problem
Possible cause
Suggested solution
_
The red telescoping steering
column* warning lamp remains
lit after starting the engine.
The adjustable steering column is not locked
properly.

Lock the steering column
(page 34).
W
The yellow low windshield and
headlamp* washer system fluid
level warning lamp remains lit af-
ter starting the engine or lights
up while driving.
The fluid level has dropped to about
1/3 of
total reservoir capacity.

Add washer fluid (
page 179).
N
The yellow low engine oil level
warning lamp remains lit after
starting the engine or lights up
while driving.
The engine oil level is too low.

Check the engine oil level
(page 172) and add oil as required
(page 175).

If you must add engine oil frequently,
have the engine checked for possible
leaks.!The low engine oil level warning light
should not be ignored. Extended driv-
ing with the light illuminated could re-
sult in serious engine damage that is
not covered by the Mercedes-Benz
Limited Warranty.

201 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
The fuel reserve and fuel cap placement
warning lamp:

lights up while driving
The fuel level has gone below the reserve
mark.

Refuel at the next gas station
(page 169).


blinks
The fuel cap is not closed tight.

Check the fuel cap.
A fuel system leak has been detected.

Have the fuel system checked as soon
as possible by an authorized
Mercedes-Benz Center
B
The yellow low engine coolant
level warning lamp remains lit af-
ter starting the engine or lights
up while driving.
The coolant level is too low.

Add coolant (
page 176).

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 light. Extended driving
with the light illuminated 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.

202 Practical hintsWhat to do if …?Problem
Possible cause
Suggested solution
#
The red charge indicator lamp
lights up while the engine is
running.
The battery was charged with a battery
charger or jump started.

Have the battery checked at a service
station.
The battery is no longer charging.
Possible causes:

alternator malfunctioning


one of the two poly-V-belts is broken

Stop immediately and check the
poly-V-belts.
If one 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:

Drive immediately to the nearest
authorized Mercedes-Benz Center.
2
The yellow brake pad wear indi-
cator lamp lights up while brak-
ing.
The brake pads have reached their wear limit.

Have the brake pads replaced as soon
as possible.
!Brake pad thickness must be visually
checked by a qualified technican
at the intervals specified in the Service
booklet.