2005 MERCEDES-BENZ CLK500 CABRIOLET check engine

359 Practical hints
What to do if …?
Problem
Possible cause
Suggested solution
A
The yellow fuel tank reserve
warning lamp comes on while
driving.
The fuel level has gone below the reserve
mark.

Refuel at the next gas station
(page 302).
C
The yellow roll bar warning lamp
comes on or flickers when the
engine is running.
The roll bar system is malfunctioning.

Release the roll bars manually.

Have the system checked at an autho-
rized Mercedes-Benz Center as soon
as possible.
<
The red seat belt telltale illumi-
nates for a brief period after
starting the engine.
The seat belt telltale reminds you to fasten
seat belts.

Fasten your seat belt.
The seat belt telltale goes out.
<
The red seat belt telltale illumi-
nates and a warning chime
sounds for approximately six
seconds after starting the en-
gine.
The driver’s seat belt is not fastened before
the engine is started.

Fasten the driver’s seat belt.
The seat belt telltale goes out.

374 Practical hintsWhat to do if …?Symbol messagesDisplay symbol
Display message
Possible cause
Possible solution
#
Visit Workshop!
The battery is no longer charging.
Possible causes:

broken poly-V-belt


alternator malfunctioning

Stop immediately and check the
poly-V-belt.
If it is broken:

Do not continue to drive. Otherwise
the engine will overheat due to an
inoperative water pump which may
result in damage to the engine. Notify
an authorized Mercedes-Benz Center.
If it is intact:

Drive immediately to the nearest
authorized Mercedes-Benz Center.
Undervoltage
Charge battery
The battery has insufficient voltage.

Start the engine (
page 46).
Undervoltage
Switch off
consumers
The battery has insufficient voltage.

Turn off unnecessary electrical con-
sumers.

375 Practical hints
What to do if …?
Display symbol
Display message
Possible cause
Possible solution
2
Brake wear
Visit workshop
The brake pads have reached their wear
limit.

Have the brake pads replaced as soon
as possible.
;
(USA only)
!
(Canada only)
Parking brake
Release brake!
You are driving with the parking brake set.

Release the parking brake
(page 49).
3
Brake fluid
Visit workshop
There is insufficient brake fluid in the res-
ervoir.

Risk of accident! 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 this message displayed can re-
sult in an accident. Have your brake system
checked immediately. Don’t add brake fluid
before checking the brake system. Overfill-
ing the brake fluid reservoir can result in
spilling brake fluid on hot engine parts and
the brake fluid catching fire. You can be se-
riously 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.
!Brake pad thickness must be visually
checked by a qualified technician at the
intervals specified in the Maintenance
Booklet.

376 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
ú
Visit workshop!
There may be a malfunction in the

fuel injection system


ignition system


exhaust system


fuel system

Have the measuring system checked
by an authorized Mercedes-Benz Cen-
ter.
B
Coolant
Check level
The coolant level is too low.

Add coolant (
page 310).

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. 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 en-
gine damage.

378 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
•
Coolant
Stop, engine off!
The poly-V-belt could be broken.

Stop immediately and 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. Notify an
authorized Mercedes-Benz Center.
If it is intact:

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.

Drive immediately to the nearest au-
thorized Mercedes-Benz Center.
Coolant
Visit workshop
!
The cooling fan for the coolant is malfunc-
tioning.

Observe the coolant temperature dis-
play.

Have the fan replaced as soon as pos-
sible.

380 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
:
USA only:Add 1 qt. engine oil
at next refuelingCanada only:Add 1 liter engine oil
at next refueling
The engine oil level is too low.

Add engine oil (
page 309) and check
the engine oil level (
page 307).
Engine oil level
Reduce oil level!
You have added too much engine oil.
There is a risk of damaging the engine or
the catalytic converter.

Have oil siphoned or drained off. Ob-
serve all legal requirements with re-
spect to its disposal.
Engine oil level
Stop, engine off!
There is no oil in the engine. There is a
danger of engine damage.

Carefully bring the vehicle to a halt as
soon as possible.

Turn off the engine.

Add engine oil (
page 309) and check
the engine oil level (
page 307).

381 Practical hints
What to do if …?
When the message
Add 1 qt. engine oil
at next refueling (Canada:
1 liter
) ap-
pears 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
approved oil specified in the Factory
Approved Service Products pamphlet.
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 307) and add oil as required
(page 309).

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.

382 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 302).
Y
Hood open!
You are driving with the hood open.

Close the hood (
page 306).
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 412).
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.
Keyless Go
Check system
The KEYLESS-GO* system is malfunction-
ing.

Visit an authorized Mercedes-Benz
Center as soon as possible.