
Key
Display messages Possible causes/consequences and
M Solutions
Â
Key does not
belong to vehicle You have put the wrong key in the ignition lock.
X
Use the correct key. Â
Replace key The key needs to be replaced.
X
Visit a qualified specialist workshop. Â
Change key batter‐
ies The batteries of the KEYLESS-GO key are discharged.
X Change the batteries ( Ypage 85). Â
Key not detected
(red display message) The KEYLESS-GO key is not in the vehicle.
Aw
arning tone also sounds.
If the engine is switched off, you can no longer loc kthe vehicle
centrally or start the engine.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 183).
X Locate the KEYLESS-GO key. The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
Aw
arning tone also sounds.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 183).
X Operate the vehicle with the key in the ignition lock if necessary. Â
Key not detected
(white display mes-
sage) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
X Operate the vehicle with the key in the ignition lock if necessary. Â
Key still in vehi‐
cle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. Display messages
297On-board computer and displays Z

Safety
Seat belts Problem Possible causes/consequences and
M Solutions
ü
Only for certain coun-
tries: the red seat belt
warning lamp lights up
for six seconds after
the engine starts. The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.
X Fasten your seat belt (Y page 52).ü
Only for certain coun-
tries: the red seat belt
warning lamp lights up
after the engine starts.
In addition, a warning
tone sounds for up to
six seconds.
The driver's seat belt is not fastened.
X
Fasten your seat belt (Y page 52).
The warning tone ceases. ü
The red seat belt warn-
ing lamp lights up after
the engine starts, as
soon as the driver's or
the front-passenger
door is closed. The driver or front passenger has not fastened their seat belt.
X
Fasten your seat belt (Y page 52).
The warning lamp goes out. There are objects on the front-passenger seat.
X
Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out. ü
The red seat belt warn-
ing lamp flashes and an
intermittenta
udible
warning sounds. The driver or passenger has no
tfastened their seat belt .Atthe
same time, the car is being driven faster than 25 km/h or has been
briefly driven faster than 25 km/h.
X Fasten your seat belt (Y page 52).
The warning lamp goes out and the intermittent warning tone
ceases. There are objects on the front-passenger seat. At the same time,
you are driving faster than 25 km/h or have briefly driven faster
than 25 km/h.
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning tone
ceases. Indicator and warning lamps in the instrument cluster
299On-board computer and displays Z

Safety systems
Problem Possible causes/consequences and
M Solutions
J
The yellow brake sys-
tem warning lamp
lights up while the
engine is running. G
WARNING
The brake system is malfunctioning and the braking characteris-
tics may be affected.
There is a risk of an accident.
X If the multifunction display shows a display message, please
observe this.
X Drive on carefully.
X Visit a qualified specialist workshop. J
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
G
WARNING
The brake boosting effect is malfunctioning and the braking char-
acteristics may be affected.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 183).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. J
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
The braking efficiency may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 183).
X Do not top up the brake fluid. Topping up will not rectify the
fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. 300
Indicator and warning lamps in the instrument clusterOn-board computer and displays

Engine
Problem Possible causes/consequences and
M Solutions
;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running.
There may be a fault, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engin emay
be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop. Vehicles with a diesel engine: the fuel tan
khas been run dry
(Y page 182).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need no tbe
checked. 8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the
star toft he scale. The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 183).
X Consult a qualified specialist workshop. Indicator and warning lamps in the instrument cluster
305On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 183).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 348).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
under 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine
is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
Steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
This poses a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 183).306
Indicator and warning lamps in the instrument clusterOn-board computer and displays

Tyres
Problem Possible causes/consequences and
M Solutions
h
The yellow tyre pres-
sure monitor warning
lamp is on. The tyre pressure monitor has detected a loss of pressure in at
leas
tone of the tyres.
G WARNING
With tyre pressures which are too low, there is a ris kofthe fol-
lowing hazards:
R the tyres may burst, especially as the load and vehicle speed
increase.
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
manoeuvres. Pay attention to the traffic conditions as you do
so.
X Secure the vehicle against rolling away (Y page 183).
X Observe the additional display messages in the multifunction
display.
X If there is a flat tyre, inspect the tyres (Y page 363).
X Check the tyre pressure (Y page 386).
X If necessary, correct the tyre pressure. 308
Indicator and warning lamps in the instrument clusterOn-board computer and displays

Useful information
i This Owner's Manual describes all mod-
els, series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos-
sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 25). Stowage areas
Loading guidelines
G
WARNING
Secure and position the load as described in
the loading guidelines.
Otherwise, vehicle occupants could
be injured by the load being thrown around in
the even tofsharp braking, a sudden change
in direction or an accident.
You will find further information in the "Secur-
ing a load" section.
Even if you follow all the loading guidelines,
the load will increase the risk of injury in the
event of an accident. G
WARNING
Keep the boot lid/tailgate closed while the
vehicle is in operation. Otherwise, exhaust
fumes could enter the vehicle interior and poi-
son you.
The handling characteristics of a laden vehi-
cle are dependent on the distribution of the
load within the vehicle. For this reason, you
should observe the following notes when
transporting a load:
R when transporting a load, never exceed the
maximum permissible gross vehicle weight or the permissible axle loads for the vehicle
(including occupants).
R position heavy loads as far forwards as pos-
sible and as low down in the boot/luggage
compartmenta s possible.
R the load must not protrude above the upper
edge of the seat backrests.
R always place the load against the rear or
front seat backrests. Make sure that the
seat backrests are securely locked into
place.
R always place the load behind unoccupied
seats if possible.
R secure the load with sufficiently strong and
wear-resistant lashing material. pad sharp
edges for protection.
i Load restraints are available at any quali-
fied specialist workshop, e.g. a Mercedes-
Benz Service Centre. Stowage compartments
Important safety notes G
WARNING
The stowage compartments must be closed
when items are stored in them. Luggage nets
are not designed to secure heavy items of
luggage.
You or other vehicle occupants could be
injured by objects being thrown around if you:
R brake sharply
R change direction suddenly
R are involved in an accident
Sharp-edged and fragile objects must not be
placed in the luggage net.
Do not place hard objects in the map pockets.
Objects must not protrude from the map
pockets. 310
Stowage areasStowing and features

an accident, the luggage net will no
tsecure
the transported goods.
Luggage nets are located in the front-
passenger footwell and on the left and right-
hand sides of the boot/luggage compart-
ment. Skibag
Unfolding the skibag and loading skis G
WARNING
The skibag is designed to carry up to four pairs
of skis. Do not use the skibag to carry any
other type of load.
The skibag must always be secured when
laden. Otherwise, injuries could be caused by
it in the event of an accident. X
Fold down the rear seat armrest.
X Press release catches ;together and fold
down cover :. X
Pull skibag :into the vehicle interior and
unfold it.
X Open the boot lid. X
Press release catch :.
The flap opens downwards.
X Slide the skis into the skibag from the boot. X
Pull strap :tight by the loose end until the
skis are held firmly inside the skibag. X
Engage hook :in securing ring ;.
X Pull the strap tight by the loose end. 314
Stowage areasStowing and features