Page 280 of 394
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).
Page 281 of 394
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.
Page 287 of 394
287 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
;
(USA only)
3
(Canada only)
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.
Page 288 of 394
288 Practical hintsWhat to do if …?Display
Possible cause
Suggested solution
F
Key
Check battery!
The SmartKey with KEYLESS-GO* batter-
ies are discharged.
Change the batteries (
page 312).
Key
not recognized!
The SmartKey with KEYLESS-GO* is not
recognized while the engine is running be-
cause
the key is not in the vehicle
there is strong radio-frequency inter-
ference
S t o p t h e v e h i c l e a s s o o n a s i t i s s a f e t o
do so.
Search for the key.
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 key in the
vehicle.
Operate the vehicle with the key in the
starter switch if necessary.
Key recognized
in vehicle
A SmartKey with KEYLESS-GO* left in the
vehicle was recognized while locking the
vehicle from the outside.
Take the key 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.
Page 289 of 394
289 Practical hints
What to do if …?
Display
Possible cause
Suggested solution
F
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 key in the
starter switch.
Message is only a reminder.
Insert key in the starter switch.
Take the SmartKey with KEY-
LESS-GO* with you when leaving the
vehicle.
B
Coolant
Check level
The coolant level is too low.
Add coolant (
page 256).
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.
Page 290 of 394
290 Practical hintsWhat to do if …?
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display
Possible cause
Suggested solution
Ï
Coolant
Stop, engine off!
The coolant is too hot.
Stop the vehicle and turn off the en-
gine.
Only start the engine again after the
message disappears. You could other-
wise 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 it
cools 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.
Page 291 of 394
291 Practical hints
What to do if …?
Display
Possible cause
Suggested 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 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.
Ï
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.
Page 292 of 394
292 Practical hintsWhat to do if …?Display
Possible cause
Suggested solution
Distronic
External interference
Reactivate!
Distronic* is switched off and is tempo-
rarily unavailable.
Try activating Distronic* again later.
Unavailable!
see oper. manual
Distronic* is switched off because the
Distronic* cover in the radiator grille is
dirty.
Clean the Distronic* cover in the radi-
ator grille (
page 271).
Restart the vehicle.
Visit workshop!
Distronic* is malfunctioning or the display
is malfunctioning.
Visit an authorized Mercedes-Benz
Center as soon as possible.
P
Selector lever
in park position
You have turned off the engine with the
KEYLESS-GO* start/stop button and
opened the driver’s door.
Place the selector lever in positionP.
J
Doors open!
You are attempting to drive with one or
more doors open.
Close the doors.
?
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.
