2004 MERCEDES-BENZ CL500 engine

305 Practical hints
What to do if …?
Display symbol
Display messages
Possible cause
Possible solution
2
BRAKE PAD WEAR
VISIT WORKSHOP!
The brake pads have reached their wear
limit.

Have the brake pads replaced as soon as
possible.
USA only:;Canada only:3
BRAKE FLUID
VISIT WORKSHOP!
There is insufficient brake fluid in the res-
ervoir.

Risk of accident! Stop the vehicle and no-
tify an authorized Mercedes-Benz Center.
Do not add brake fluid! This will not solve
the problem.
USA only:;Canada only:!
PARK. BRAKE
RELEASE BRAKE!
You are driving with the parking brake en-
gaged.

Release the parking brake (
page 47).
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 Service Book-
let.

306 Practical hintsWhat to do if …?Display symbol
Display messages
Possible cause
Possible solution
?
VISIT WORKSHOP!
There may be a malfunction in the:

Fuel injection system


Ignition system


Exhaust system


Fuel system

Visit an authorized Mercedes-Benz
Center as soon as possible.
B
COOLANT
CHECK LEVEL!
The coolant level is too low.

Add coolant (
page 266).

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 a sufficient
amount of coolant in the cooling sys-
tem. The engine will overheat, causing
major engine damage.

307 Practical hints
What to do if …?
During severe operating conditions,
e.g. stop-and-go traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbol
Display messages
Possible cause
Possible solution
Ï
COOLANT
STOP, ENGINE OFF!
The coolant is too hot.

Stop the vehicle and turn off the engine.

Only start the engine again after the mes-
sage disappears. You could otherwise
damage the engine.
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 the
engine has cooled down.
!The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
engine damage which is not covered by
the Mercedes-Benz Limited Warranty.

308 Practical hintsWhat to do if …?Display
Display messages
Possible cause
Possible solution
Ï
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 inoperative
water pump which may result 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 Limit-
ed Warranty.
Ï
COOLANT
VISIT WORKSHOP!
The cooling fan for the coolant is malfunc-
tioning.

Observe the coolant temperature display.

Have the fan replaced as soon as possi-
ble.

310 Practical hintsWhat to do if …?Display symbol
Display message
Possible cause
Possible solution
:
USA only:ADD 1.0 QT. ENGINE
OIL
AT NEXT REFUELING!Canada only:ADD 1.0 LITER ENGINE
OIL
AT NEXT REFUELING!
The engine oil level is too low.

Add engine oil (
page 265) and check
the engine oil level (page 262).
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 265) and check
the engine oil level (page 262).
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 excess oil siphoned or drained off.
Observe all legal requirements with re-
spect to its disposal.

311 Practical hints
What to do if …?
When the message
ADD 1.0 QT. ENGINE
OIL AT NEXT REFUELING!
(Canada:
1 Liter
) appears while the engine is run-
ning and at operating temperature, the en-
gine 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 level checked
(page 262).
ENGINE OIL LEVEL
VISIT WORKSHOP!
The engine oil has dropped to a critical
level.

Check the engine oil level (
page 262)
and add engine oil as required
(
page 265).

If you must add engine oil frequently,
have the engine checked for possible
leaks.
ENGINE OIL SENSOR
VISIT WORKSHOP!
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.

313 Practical hints
What to do if …?
Display symbol
Display messages
Possible cause
Possible solution
F
KEY
CHECK BATTERY
The battery in the KEYLESS-GO* key is
discharged.

Change the battery (
page 332).
KEY
NOT RECOGNIZED!
SmartKey with KEYLESS-GO* is not rec-
ognized while the engine is running be-
cause

the SmartKey with KEYLESS-GO* 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 with
KEYLESS-GO*.
Otherwise the vehicle cannot be centrally
locked nor can the engine be started again
after it has been stopped.
SmartKey with KEYLESS-GO* is momen-
tarily not recognized.

Change the position of the SmartKey with
KEYLESS-GO* in the vehicle.

Operate the vehicle with the SmartKey in
the starter switch if necessary.
KEY
DETECTED IN VEHICLE
SmartKey with KEYLESS-GO*left in the
vehicle was recognized while locking the
vehicle from the outside.

Take the SmartKey with KEYLESS-GO*
out of the vehicle.
KEY
DRIVE TO WORKSHOP!
The KEYLESS-GO* system is malfunction-
ing.

Visit an authorized Mercedes-Benz Cen-
ter as soon as possible.

319 Practical hints
What to do if …?
Display symbol
Display messages
Possible cause
Possible solution
t

FUNCTION
NOT AVAILABLE!
This display appears if button t or
son the multifunction steering wheel
is pressed and the vehicle is not equipped
with a telephone.
Ê
TRUNK OPEN!
This message will appear whenever the
trunk lid is open.

Close the trunk lid.
W
WASHER FLUID
CHECK LEVEL!
The fluid level has dropped to about
1/3
of total reservoir capacity.
Add washer fluid (
page 269).
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.