Page 380 of 521
379 Practical hints
What to do if …
Problem
Possible cause/consequence
Suggested solution
D
The red coolant warning lamp
comes on when the engine is
running.
There is insufficient coolant in the reservoir.
If this warning lamp comes on frequently,
there is a leak in the cooling system.
If the coolant level is correct, the electric ra-
diator fan may be broken.
Immediately add coolant to prevent
engine from overheating
(page 325).
Have the cooling system checked.
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
comes on while driving and you
hear a warning sound.
The coolant temperature has exceeded
257°F (125°C).
Stop as soon as possible in a safe lo-
cation and allow the engine and cool-
ant 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 the
engine has cooled down.
Page 399 of 521
398 Practical hintsWhat to do if …Symbol messagesDisplay symbol
Display messages
Possible cause/consequence
Possible solution
#
Low voltage
Switch off
consumers
The battery has insufficient voltage.
Turn off unnecessary electrical con-
sumers.
Visit workshop
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
broken poly-V-belt
Do not forget that the brake system re-
quires electrical energy and may be oper-
ating with restricted capability.
Considerably greater brake pedal force is
required and the stopping distance is in-
creased.
Stop immediately in a safe location or
as soon as it is safe to do so 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:
Drive immediately to the nearest au-
thorized Mercedes-Benz Center. Ad-
just driving to be consistent with
reduced braking responsiveness.
Page 402 of 521
401 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
(USA only);(Canada only)3
Reduced braking power
Visit workshop
The electrohydraulic brake system is in
emergency operation mode. Consider-
able brake pedal force is required and the
stopping distance is increased.
Continue driving with added caution.
Adjust driving to be consistent with
reduced braking responsiveness.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Service brake
Visit workshop
There are malfunctions, but the electro-
hydraulic brake system is operating nor-
mally.
Visit an authorized Mercedes-Benz
Center as soon as possible.
Brake overheated
Drive on, but with
even greater care
The brake system is overheated due to an
excessive load on the brakes.
Relieve the load on the brake system.
Drive more smoothly and think ahead
to avoid unnecessary braking.
When driving down slopes, shift into a
lower gear to use the engine’s braking
power (
page 190).
Cautiously continue driving so that
the air stream will cool down the
brakes.
Release parking
brake
You are driving with the parking brake
set.
Release the parking brake
(page 53).
Page 404 of 521
403 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
ú
(USA only)
±
(Canada only)
Engine
Service
There may be a malfunction in the:
fuel injection system
ignition system (Gasoline engine)
exhaust system
fuel system
Have the measuring system checked
by an authorized Mercedes-Benz
Center.
B
Coolant
Check level
The coolant level is too low.
Add coolant (
page 325).
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 405 of 521
404 Practical hintsWhat to do if …
During severe operation conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbol
Display messages
Possible cause/consequence
Possible solution
Ï
Coolant
Stop, engine off
The coolant is too hot.
Stop the vehicle in a safe location or
as soon as it is safe to do so.
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 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
damage which is not covered by the
Mercedes-Benz Limited Warranty.
Page 406 of 521
405 Practical hints
What to do if …
Display symbol
Display messages
Possible cause/consequence
Possible solution
Ï
Coolant
Stop, engine off
The poly-V-belt could be broken.
Stop the vehicle in a safe location or as soon
as it is safe to do so and immediately turn
off the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the en-
gine will overheat due to an inoperative wa-
ter 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 re-
sult in serious engine damage that is not
covered by the Mercedes-Benz Warranty.
Drive immediately to the nearest authorized
Mercedes-Benz Center.
Coolant
Visit workshop
The cooling fan for the coolant is malfunc-
tioning.
Observe the coolant temperature display.
Have the fan replaced as soon as possible.
