
R
ESP ®
is deactivated.
R a loss of tyre pressure or a defective tyre is
detected.
Activating Active Blind Spo tAssist
X Make sure that the radar sensor system
(Y page 262) and Active Blind Spot Assist
(Y page 257) are activated in the on-board
computer.
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow.
Towing atrailer
If you attach a trailer, make sure tha tyou have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Active Blind Spot Assist is
then deactivated. The indicator lamp lights up
yellow in the exterior mirrors and the ActiveBlind Spot Assist currently unavail‐
able See Owner's Manual message
appears in the multifunction display.
Active Lane Keeping Assist Important safety notes
G
WARNING
Active Lane Keeping Assist does not keep
your vehicle in its lane. It is only an aid and
may detect the lane markings on the road
incorrectly or not at all.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to inade-
quate illumination of the road surface,
snow, rain, fog or spray.
R there is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles.
R the windscreen is dirty, fogged up or cov-
ered, for instance by a sticker, in the vicinity
of the camera. R
several or no lane markings for a single lane
are present.
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow.
R the distance to the vehicle in front is too
small and as a result the lane markings can-
not be recognised.
R the lane markings on the road are unclear,
e.g. near roadworks.
R the lane markings change quickly, e.g.
branch off, cross, or merge.
R the road is narrow and winding.
Active Lane Keeping Assist cannot detect
road and traffic conditions. It is not a substi-
tute for attentive driving. You are responsible
for the vehicle's speed, braking in good time,
and steering correctly. Always adapt your
driving style to suit the prevailing road and
weather conditions. Always pay attention to
traffic conditions and your surroundings. Oth-
erwise, you may fail to recognise dangers in
time, cause an accident and injure yourself
and others.
General notes Active Lane Keeping Assist monitors the area
in front of your vehicle by means of a cam-
era :at the top of the windscreen. Active
Lane Keeping Assist detect slane markings on
the road and warns you before you leave your
lane unintentionally. If you do no treact to the
warning, a lane-correcting application of the
brakes can bring the vehicle back into the
original lane. 232
Driving systemsDriving and parking

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). Important safety notes
G
WARNING
Only use the on-board computer when road
and traffic conditions permit .You would oth-
erwise be distracted and unable to concen-
trate properly on driving, and could cause an
accident. G
WARNING
No messages will be displayed if either the
instrument cluster or the multifunction dis-
play is inoperative.
As a result, you will not be able to see infor-
mation about your driving conditions, such as
speed, outside temperature, warning and indi-
cator lamps, display messages or system fail-
ures. Driving characteristics may be impaired.
Adjust your driving style and vehicle speed
accordingly.
Contact a qualified specialist workshop
immediately. G
WARNING
The on-board computer only records and dis-
plays malfunctions and warnings from certain
systems. For this reason, you should always
make sure that your vehicle is safe to use. You
could otherwise cause an accident by driving
an unsafe vehicle. G
WARNING
The operating safety of your vehicle could be
impaired if maintenance work is carried out
incorrectly. This could cause you to lose con-
trol of your vehicle and cause an accident.
Moreover, the safety systems may no longer
be able to protect you or others as they are
designed to do.
Always have service work carried out at a
qualified specialist workshop. G
WARNING
Hybrid vehicles: ensure that you read the
"HYBRID" supplement. You could otherwise
fail to recognise dangers.
For an illustration of the instrument cluster,
see (Y page 32). 244
Important safety notesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
J
Check brake fluid
level There is insufficien
tbrake fluid in the brake flui dreservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
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 .Donot continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 183).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake pad
wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. PRE-SAFE
inoperative See
Owner's Manual Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. 272
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
PRE-SAFE
Functions cur‐
rently limited See
Owner's Manual PRE-SAFE
®
Brake is temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow.
R the sensors in the radiato rtrim and in the bumpers are dirty.
R the rada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R AMG vehicles: ESP ®
is deactivated.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
PRE-SAFE ®
Brake is operational again.
If the display message does not disappear:
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 Clean the sensors in the radiator trim and in the bumpers
(Y page 354).
X Restart the engine.
X AMG vehicles: reactivate ESP ®
(Y page 74). PRE-SAFE
Functions cur‐
rently limited See
Owner's Manual PRE-SAFE
®
Brake is inoperative due to a fault. BAS PLUS or the
distance warning signal may also have failed.
X Visit a qualified specialist workshop. ü If the symbol appears in the multifunction display,
aseat belt
tongue has been inserted into a rear seat belt buckle.
For further information on the status indicator for the rear seat
belts: (Y page 54). Display messages
273On-board computer and displays Z

Engine
Display messages Possible causes/consequences and
M Solutions
+
Top
up coolant See
Owner's Manual The coolant level is too low.
!
Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing
so (Y page 348).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? The fan motor is faulty.
X
If the coolant temperature is below 120 †, you can continue
driving to the neares tqualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. ?
Coolant Stop vehi‐
cle Switch engine
off The coolan
tis too hot.
Aw arning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine
is overheated can cause som efluids which may have leaked into
the engine compartment to catch fire.
Steam fro manoverheated engine can cause serious burns, which
can occur just by opening the bonnet.
This poses a risk of injury.
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 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 display message goes out
and the coolant temperature is under 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visi taqualified specialist
workshop immediately.
The reading may rise up to 120 †undernormal driving conditions
if the coolant has been filled correctly. Display messages
279On-board computer and displays Z

Driving systems
Display messages Possible causes/consequences and
M Solutions
À
Attention Assist:
Take a break! Based on certain criteria, ATTENTION ASSIST has detected fatigue
or
alack of concentration on th epart of th edriver. A warning tone
also sounds.
X If necessary, take a break.
During long journeys, take regular breaks in good time so that you
get enough rest. À
Attention Assist
inoperative ATTENTION ASSIST is inoperative.
X
Visi taqualified specialist workshop. ¨or°
Vehicle rising Your vehicle is adjusting to the level you have selected.
¨or°
Vehicle rising
Please wait The vehicle level is too low when the vehicle is stationary.
Awarn-
ing tone also sounds.
X Do no tpull away.
The vehicle level is set when the display message disappears. ¨or
°
STOP vehicle Vehi‐ cle too low You have pulled away while the vehicle level is still too low.
AIRMATIC sets the vehicle to the selected level after a short
period.
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 Wait until the display message disappears before pulling away. AIRMATIC is faulty.
Awarning tone also sounds.
X Do not exceed a maximum speed of 80 km/h.
X Make only sligh tsteering movements. Otherwise, the front
wings or the tyres could be damaged if the steering movement
is too large.
X Liste nfor scraping sounds.
X Pull over and stop the vehicle safely, paying attention to road
and traffic conditions, and select a higher vehicle level.
Depending on the malfunction, it may be possible to raise the
vehicle.
X Visit a qualified specialist workshop. 282
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
¨or
°
Malfunction The AIRMATIC function is restricted. The vehicle's handling char-
acteristics may be affected.
X Do not drive at speeds above 80 km/h.
X Visit a qualified specialist workshop. Speed Limit Assist
currently unavail‐
able See Owner's
Manual Speed Limit Assis
tis deactivated and temporarily inoperative.
Possible causes:
R the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
X Cleant he windscreen.
If the system detects that the camera is fully operational, the dis-
play message disappears.
Speed Limit Assist is operational again. Speed Limit
Assist: Unavaila‐
ble in this country Speed Limit Assist is only available in certain countries.
X Drive on.
Speed Limit Assist is available again as soon as you drive in a
country in which its use is approved. Speed Limit Assist
inoperative Speed Limit Assist is faulty.
X
Visit a qualified specialist workshop. ë
off The HOLD function is deactivated. The vehicle is skidding.
Aw
arning tone also sounds.
X Reactivate the HOLD function later (Y page 205). The HOLD function is deactivated. When the brak
epedal is firmly
depressed, an activation condition is not fulfilled.
Aw arning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 205). Radar sensor deac‐
tivated See Own‐
er's Manual The radar sensor system is deactivated.
X
Chec kwhether or not the radar sensor system may be activated
(Y page 451).
X Activate the radar sensor system (Y page 262). Display messages
283On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions
Radar sensor deac‐
tivated autom. See
Owner's Manual Vehicles with a navigation system: the vehicle is close to a radio
telescope facility and is therefore prohibited from transmitting any
rada
rsignals .The radar sensor system has switched off automat-
ically (Y page 451).
If DISTRONIC PLUS was activated, it is no longer available. A
warning tone also sounds.
If Blind Spot Assist or Active Blind Spot Assist was activated, it is
no longer available. The yellow 9indicator lamps also light up
in the exterior mirrors.
BAS PLUS (Brake Assist PLUS) and PRE-SAFE ®
Brake are then also
unavailable.
X Drive on.
Once you have moved far enough away from the radio telescope,
the above functions are available again. Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is
not connected, the radar sensor system is deactivated automati-
cally.
BAS PLUS, DISTRONIC PLUS, Blind Spot Assist or Active Blind
Spot Assist and PRE-SAFE ®
Brake are unavailable.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Lane Keeping
Assist currently
unavailable See
Owner's Manual or
Active Lane Keep‐ ing Assist cur‐
rently unavailable
See Owner's Manual Lane Keeping Assist or Active Lane Keeping Assist is deactivated
and temporarily inoperative. Possible causes:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for a longer period.
R the lane markings are worn, dark or covered, e.g. by dirt or snow.
Once the causes listed above no longer apply, the display message
goes out.
Lane Keeping Assist or Active Lane Keeping Assist is operational
again.
If the display message does not disappear:
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 Cleant he windscreen. 284
Display messagesOn-board computer and displays