
Display messages Possible causes/consequences and
M Solutions
T!
÷
inoperative See
Owner's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, PRE-
SAFE ®
, the HOLD function ,hill start assist and ESP ®
trailer stabi-
lisatio nare unavailable due to a malfunction.
The adaptive brake lights, BAS PLUS and PRE-SAFE ®
Brake may
also have failed.
In addition, the ä,åand! warning lamps light up in
the instrument cluster and a warning tone sounds.
G WARNING
The brake system continues to function normally, but withou tthe
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. J
Release parking
brake You are driving with the parking brake applied.
Awarning tone also
sounds.
X Release the parking brake. J
Brake immediately or
Vehicles with manual transmission
:with the HOL Dfunction acti-
vated, you have either:
R opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet.
At one may also sound at regular intervals. If you attempt to lock
the vehicle, the tone becomes louder.
You cannot start the engine.
X Paying attention to the traffic situation, immediately depress the
brake pedal firmly and hold until the display message disap-
pears.
X Secure the vehicle against rolling away (Y page 177).
You can restart the engine. 252
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
¸
Please
replace air
cleaner Vehicles with a diesel engine: the engine air filte
ris dirty and must
be replaced.
X Visit a qualified specialist workshop. !
Clean
the fuel fil‐
ter Vehicles with a diesel engine: there is water in the fuel filter. The
water must be drained off.
X
Visit a qualified specialist workshop. 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. Speed Limit Assist
currently unavail‐
able See Owner's
Manual Speed Limit 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.
X Clean the 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. 262
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Lane Keeping
Assist currently
unavailable See
Owner's Manual or
Active Lane Keep‐ ing Assist cur‐
rently unavailable
See Owner's Manual Lane Keeping Assis
torActive 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 177).
X Clean the windscreen. Lane Keeping
Assist inopera‐
tive or
Active Lane Keeping
Assist inoperative Lane Keeping Assist or Active Lane Keeping Assist is faulty.
X
Visit a qualified specialist workshop. Blind Spot Assist
currently unavail‐
able See Owner's
Manual or
Active Blind Spot Assist
currently unavail‐
able See Owner's
Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative.
You have established the electrical connection between the trailer
and your vehicle.
X
Press aon the steering wheel to confirm the display mes-
sage.
Blind Spot Assist or Active Blind Spot Assist is deactivated while
towing a trailer. 264
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
Blind Spot Assis
torActive Blind Spot Assist is temporarily inop-
erative .Possible causes:
R the sensors are dirty.
R the function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
Once the causes listed above no longer apply, the display message
goes out.
Blind Spot Assist or Active Blind Spot 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 177).
X Clean the sensors (Y page 317).
X Restart the engine. Blind Spot Assist
inoperative or
Active Blind Spot Assist inoperative Blind Spot Assist or Active Blind Spot Assist is faulty.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Parking Guidance
inoperative Parking Guidance is malfunctioning (Y
page 203).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. Display messages
265On-board computer and displays Z

Safety systems
Problem Possible causes/consequences and
M Solutions
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 177).
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. !
The yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Brake System) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
,P RE-SAFE ®
Brake ,the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are also deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will not be available. Warning and indicator lamps in the instrument cluster
277On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is not available due to a malfunction. Therefore, ABS, BAS,
BAS PLUS, ESP
®
, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Jäå!
The red brake warning
lamp, the yellow ESP
®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are not available due to a fault. Therefore, BAS, BAS
PLUS, EBD,P RE-SAFE®
,P RE-SAFE ®
Brake, the HOLD function, hill
start assist, the adaptive brake lights and ESP ®
trailer stabilisa-
tion, for example, are no tavailable either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The dange rofskidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visi taqualified specialist workshop. 278
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
ä
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. ESP
®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X Only depress the accelerator pedal as far as necessary when
pulling away.
X Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions, see: (Y page 67).å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. ESP
®
is deactivated.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Reactivate ESP ®
.
For exceptions, see: (Y page 67).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Have ESP ®
checked at a qualified specialist workshop. äå
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are not available due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
279On-board computer and displays Z

The vehicle tool kit contains:
R
Cabriolet: straps for emergency release of
the soft top
R Foldable wheel chock
R Fuse allocation chart
R Jack
R Centring pin
R One pair of gloves
R wheel wrench
R Towing eye Flat tyre
Preparing the vehicle
Information on changing a wheel/fitting
(Y page 346).
Vehicle preparation is not necessary on vehi-
cles with MOExtended tyres.
Your vehicle may be equipped with:
R MOExtended tyres (tyres with run-flat char-
acteristics) (Y page 324)
R a TIREFIT kit (Y page 325)
R an emergency spare wheel (only for certain
countries) (Y page 363)
X Stop the vehicle as far away as possible
from traffic on solid, non-slippery and level
ground.
X Switch on the hazard warning lamps.
X Apply the parking brake.
X Bring the frontw heels into the straight-
ahead position.
X Shift the transmission to position P.
X Switch off the engine.
X Vehicles without KEYLESS-GO: remove
the key from the ignition lock.
X Vehicles with KEYLESS-GO: open the
driver's door.
The on-board electronics have status 0,
which is the same as the key having been
removed. X
Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
(Y page 159).
X All occupants must get out of the vehicle.
Make sure that they are not endangered as
they do so.
X Make sure that no one is near the danger
area while a wheel is being changed. Any-
one who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.
X Get out of the vehicle. Pay attention to traf-
fic conditions when doing so.
X Close the driver's door.
X Place the warning triangle a suitable dis-
tance away (Y page 322). Observe legal
requirements. MOExtended tyres (tyres with run-flat
characteristics)
G
WARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a risk of accident.
Do not exceed the stated maximum speed.
Avoid abrupt steering and driving manoeu-
vres, and driving over obstacles (kerbs, pot-
holes, off-road). This applies in particular to a
laden vehicle.
Stop driving in emergency mode if:
R you hear banging noises.
R the vehicle starts to shake.
R you see smoke and smell rubber.
R ESP ®
is intervening constantly.
R there are tears in the sidewalls of the tyre.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
faulty tyre must be replaced.
With MOExtended tyres (tyres with run-flat
characteristics), you can continue to drive 324
Flat tyreBreakdown assistance