Page 249 of 426
249 Operation
At the gas station
Coolant
For normal replenishing, use water (pota-
ble water quality). For more information,
see “Coolant” (
page 255) and see “Fu-
els, coolants, lubricants, etc.”
(
page 393).
Engine oil level
For more information on engine oil level,
see “Engine oil” (
page 253).
Brake fluidWindshield washer and headlamp
cleaning system
For more information on filling up the
washer reservoir, see “Windshield washer
system and headlamp cleaning system”
(
page 257).
Vehicle lighting
Check function and cleanliness. For more
information on replacing light bulbs, see
“Replacing bulbs” (
page 361).
For more information on exterior lamps,
see “Exterior lamp switch” (
page 106).Tire inflation pressure
For more information on tire inflation pres-
sure, see “Checking tire inflation pressure
manually” (
page 271).
!
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 immediately. Notify an
authorized Mercedes-Benz Center immediately.
Do not add brake fluid as this will not solve the
problem. For more information, see “Practical
hints” (page 307).
Page 250 of 426
250 OperationEngine compartmentHood OpeningWarning!
G
Do not pull the release lever while the
vehicle is in motion. Otherwise the hood
could be forced open by passing air flow.
This could cause the hood to come loose
and injure you and/or others.Warning!
G
The exhaust areas on the engine hood and
between the doors and front wheels get very
hot. Avoid contact with them, otherwise
there is the risk of severe burns.
Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from the vehicle and do not open the
hood until the engine has cooled. If neces-
sary, call the fire department.Warning!
G
You could be injured when the hood is open
– even when the engine is turned off.
Parts of the engine can become very hot. To
prevent burns, let the engine cool off com-
pletely before touching any components on
the vehicle. Comply with all relevant safety
precautions.
Warning!
G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may also start at any time
automatically, even after the SmartKey has
been removed from the starter switch. Stay
clear of fan blades.Warning!
G
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnos-
tic socket) of the ignition system
with the engine running
while starting the engine
if ignition is “on” and the engine is
turned manually
Page 255 of 426
255 Operation
Engine compartment
Coolant
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking coolant level,
the vehicle must be parked on level
ground
the coolant temperature must be be-
low 158°F (70°C)
1Expansion tank
Using a rag, turn cap slowly approxi-
mately one half turn to the left to
release any excess pressure.
Continue turning the cap to the left and
remove it.
The coolant level is correct if the level
for cold coolant: reaches the upper
mark on the bracing rib of the ex-
pansion tank (arrow)
for warm coolant: is approximately
0.4 in (1 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information, see “Coolants”
(
page 398).
Warning!
G
In order to avoid potentially 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 coolant temperature is
above 158°F (70°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
approximately
1/2 turn to relieve excess
pressure. If opened immediately, scald-
ing hot fluid and steam will be blown out
under pressure.
Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.
Page 310 of 426
310 Practical hintsWhat to do if ...
During severe operating conditions, e.g.
stop-and-go traffic, the coolant tempera-
ture may rise close to 248°F (120°C).
Problem
Possible cause/consequence
Suggested solution
D
The red coolant temperature
warning lamp comes on while
the engine is running.
There is insufficient coolant in the reservoir.
Immediately add coolant to prevent en-
gine from overheating (
page 255).
If this warning lamp comes on frequently,
there is a leak in the cooling system.
Have the cooling system checked by
an authorized Mercedes-Benz Center.
If the coolant level is correct, the electric
radiator fan may be broken.
If the coolant temperature is below
248°F (120°C), you can continue driv-
ing to the nearest authorized
Mercedes-Benz Center.
Avoid high engine loads (e.g. driving
uphill) and stop-and-go driving.
D
The red coolant temperature
warning lamp comes on while
the engine is running and you
hear a warning sound.
The coolant temperature has exceeded
248°F (120°C).
Stop as soon as possible in a safe loca-
tion and allow the engine and coolant
to cool down.
Warning!
G
Driving when your engine is overheated 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 which can occur just by open-
ing the engine hood. Stay away from the en-
gine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. 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). Do-
ing so may cause serious engine damage which
is not covered by the Mercedes-Benz Limited
Warranty.
Page 340 of 426
340 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
B
Top Up
Coolant
See Oper. Manual
The coolant level is too low.
Add coolant (
page 255).
Comply with all warnings while doing so.
If you have to add coolant frequently, have the cooling
system checked by an authorized Mercedes-Benz Center
immediately.
•
The cooling fan for the coolant
is malfunctioning.
Observe the coolant temperature gauge in the instru-
ment cluster (
page 29).
If the coolant temperature is below 248°F (120°C), you
may continue driving to the nearest specialist workshop.
Avoid placing heavy loads on the engine (e.g. by driving
uphill) as well as stop-and-go traffic.
Have the fan replaced as soon as possible.
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.
!
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 engine damage.
Page 341 of 426
341 Practical hints
What to do if ...
Left display
Right display
Possible cause/
consequence
Possible solution
•
Coolant
Stop car,
switch engine off.
The coolant is too hot.
Among other possible causes,
the poly-V-belt could be
broken.
Stop the vehicle in a safe location or as soon as it is safe
to do so.
Turn off the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise, the engine will over-
heat due to an inoperative water pump which may result
in damage to the engine. Contact an authorized
Mercedes-Benz Center.
If it is intact:
Wait for the message to disappear before restarting the
engine.
Doing otherwise could result in serious engine damage
that is not covered by the Mercedes-Benz Limited War-
ranty.
(Continued on next page)
Page 342 of 426
342 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).
Left display
Right display
Possible cause/
consequence
Possible solution
Observe the coolant temperature gauge in the
instrument cluster (
page 29).
If the temperature rises again:
Contact an authorized Mercedes-Benz Center
immediately.
Warning!
G
Driving when your engine is overheated 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 which can occur just by open-
ing the hood. Stay away from the engine if
you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. 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.
Page 344 of 426
344 Practical hintsWhat to do if ...Left display
Right display
Possible cause/
consequence
Possible solution
±
Service
Required
Certain electronic systems are
unable to relay information to
the control system. The follow-
ing systems may have failed:
Coolant temperature gauge
Tachometer
Have the electronic systems checked by an authorized
Mercedes-Benz Center immediately.
Fuel System
Malfunction
Service
Required
The fuel cooling system is
malfunctioning.
Contact an authorized Mercedes-Benz Center
immediately.
:
Engine
Oil Pressure
Service
Required
There is no oil in the engine.
There is a danger of engine
damage.
Stop your vehicle immediately in a safe location.
Switch off the engine.
Do not drive any further.
Contact an authorized Mercedes-Benz Center
immediately.
!
The engine oil level warning 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.
