Up to a speed of approximately 44 mph
(70 km/h), Adaptive Brake Assist reacts to
stationary obstacles.
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
Ryou release the brake pedal.
Rthere is no longer any danger of a collision.
Rno obstacle is detected in front of your
vehicle.
Adaptive Brake Assist is then deactivated.
Important safety notes
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
Rintervene unnecessarily
Rnot intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
GWARNING
Adaptive Brake Assist does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen cornering
As a result, the Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause Brake Assist to inter-
vene. If adaptive Brake Assist is not available due to
a malfunction in the radar sensor system, the
brake system remains available with full
brake boosting effect and BAS.
Detection of hazardous situations can be par-
ticularly impaired by:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is snow or heavy rain
Rthere is interference by other radar sources
Rthere are strong radar reflections, for
example in parking garages
Ra narrow vehicle traveling in front, e.g. a
motorbike
Ra vehicle traveling in front on a different line
Rnew vehicles after the first few kilometers
of driving or after the COLLISION PREVEN-
TION ASSIST PLUS system has been serv-
iced
Observe the important safety notes in the
"Breaking-in notes" section (
Ypage 138).
Following damage to the front end of the vehi- cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at low speeds where there is no visible
damage to the front of the vehicle.
ESP®(Electronic Stability Program)
General notes
iObserve the "Important safety notes" sec-
tion (
Ypage 61).
ESP
®monitors driving stability and traction,
i.e. power transmission between the tires and
the road surface.
If ESP
®detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP
®assists the driver when
Driving safety systems65
Safety
Z
XPress mechanical key;into the SmartKey
opening in the direction of the arrow until
battery compartment cover :opens. Do
not hold battery compartment cover :
closed while doing so.
XRemove battery compartment cover :.
XRepeatedly tap the SmartKey against your
palm until battery=falls out.
XInsert the new battery with the positive ter-
minal facing upwards. Use a lint-free cloth
to do so.
XMake sure that the surface of the battery is
free of lint, grease and other contaminants.
XInsert the front tabs of battery compart-
ment cover :into the housing and then
press to close it.
XInsert mechanical key ;into the Smart-
Key (
Ypage 74).
XCheck the function of all SmartKey buttons
on the vehicle.
76SmartKey
Opening and closing
If a malfunction in the electric parking brake
occurs, then the transmission may also be
shifted into positionPautomatically.
PARKTRONIC
Important safety notes
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is only an aid. It is not a replace-
ment for your attention to your immediate
surroundings. You are always responsible for
safe maneuvering, parking and exiting a park-
ing space. When maneuvering, parking or
pulling out of a parking space, make sure that
there are no persons, animals or objects in
the area in which you are maneuvering.
!When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is activated automatically when
you:
Rswitch on the ignition
Rmove the selector lever to position D,R or
N on vehicles with automatic transmission
Rrelease the electric parking brake.
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds. PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Range of the sensors
General notes
PARKTRONIC does not take objects into con-
sideration that are:
Rbelow the detection range, e.g. people, ani-
mals or objects.
Rabove the detection range, e.g. overhang-
ing loads, truck overhangs or loading
ramps.
:Sensors in the front bumper, left-hand
side (example)
Side view
Driving systems181
Driving and parking
Z
means of intermittent vibration in the steer-
ing wheel for up to 1.5 seconds.
Important safety notes
GWARNING
Lane Keeping Assist may not always clearly
recognize lane markings.
In this case, Lane Keeping Assist may:
Rgive an unnecessary warning
Rnot give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and stay in lane, in particular if
warned by Lane Keeping Assist.
GWARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There is
a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane Keep-
ing Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an accident nor override the laws of physics.
Lane Keeping Assist cannot take into account
the road, traffic and weather conditions. Lane
Keeping Assist is merely an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time and for staying in your lane.
The Lane Keeping Assist does not keep the
vehicle in the lane.
The system may be impaired or may not func- tion if:
Rthere is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray
Rthere is glare, e.g. from oncoming traffic,
the sun or reflections (e.g. when the road
surface is wet)
Rthe windshield is dirty, fogged up, damagedor covered, for instance by a sticker, in the
vicinity of the camera
Rthere are no, several or unclear lane mark-
ings for a lane, e.g. in areas with road con-
struction work
Rthe lane markings are worn away, dark or
covered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
Rthe lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
Rthe road is narrow and winding
Rthere are strong shadows cast on the lane
Switching on Lane Keeping Assist
XSwitch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
or Adaptive(Ypage 204).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected, the lines in the assistance graphics display
(
Ypage 203) are shown in green. Lane
Keeping Assist is ready for use.
Standard
If Standard
is selected, no warning vibration
occurs if:
Ryou switch on the turn signals. In this event, the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Adaptive
When Adaptive
is selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, e.g.
ABS, BAS or ESP®.
Ryou accelerate hard, e.g. kickdown.
Ryou brake hard.
190Driving systems
Driving and parking
Safety systems
Display messagesPossible causes/consequences andMSolutions
!÷
Currently Unavail‐
able See Opera‐
tor's Manual
ABS (Anti-lock Braking System), ESP®(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE ‑SAFE®, the HOLD function and hill
start assist are temporarily unavailable.
COLLISION PREVENTION ASSIST PLUS may also have failed.
In addition, the ÷,åand! warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes are:
Rself-diagnosis is not yet complete.
Rthe on-board voltage may be insufficient.
GWARNING
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 stabilize the vehicle.
There is an increased risk of skidding and an accident.
XCarefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the multifunction display still shows the display message:
XDrive on carefully.
XVisit a qualified specialist workshop.
!÷
Inoperative See
Operator's Manual
ABS, ESP®, BAS, PRE‑SAFE®, the HOLD function and hill start
assist are unavailable due to a malfunction.
COLLISION PREVENTION ASSIST PLUS may also have failed.
The $ (USA only) or J(Canada only), ÷,åand!
warning lamps in the instrument cluster also light up.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
212Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
÷
Inoperative See
Operator'sManual
ES P®,BAS, PRE‑ SAF E®,th eHOLD function and hill start assist are
unavailable due to amalfunction .
COLLISION PREVENTION ASSIST PLU Smay also hav efailed.
In addition ,th e÷ andå warnin glamp sligh tup in th e
instrumen tcluster.
ATTENTION ASSIST is deactivated.
GWARNIN G
The brakesystem continues to function normally, but without th e
function slisted above.
The brakin gdistanc ein an emergenc ybrakin gsituation can thus
increase .
If ES P
®is no toperational, ES P®is unable to stabiliz eth evehicle.
There is an increase dris kof skiddin gand an accident.
XDrive on carefully.
XVisit aqualified specialist workshop .
T!
÷
Inoperative See
Operator'sManual
EB D(electronic brak eforc edistribution), ABS, ES P®,BAS, PRE -
SAFE®, th eHOLD function and hill start assist are unavailable due
to amalfunction .
COLLISION PREVENTION ASSIST PLU Smay also hav efailed.
In addition ,th e÷, åand! warnin glamp sligh tup in th e
instrumen tcluster and awarnin gtone sounds.
GWARNIN G
The brakesystem continues to function normally, but without th e
function slisted above. The fron tand rear wheels could therefore
loc kif you brak ehard, fo rexample.
The steerabilit yand brakin gcharacteristics may be severely affec -
ted. The brakin gdistanc ein an emergenc ybrakin gsituation can
increase .
If ES P
®is no toperational, ES P®is unable to stabiliz eth evehicle.
There is an increase dris kof skiddin gand an accident.
XDrive on carefully.
XVisit aqualified specialist workshop immediately.
214Display messages
On-board computer and displays
Safety systems
ProblemPossible causes/consequences andMSolutions
$(USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds.There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
XSecure the vehicle against rolling away (Ypage 160).
XDo not add brake fluid. Adding more will not remedy the mal-
function.
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction
display.
!
The yellow ABS warning
lamp is lit while the
engine is running.ABS (Anti-lock Braking System) is deactivated due to a malfunc-
tion. Therefore, BAS (Brake Assist), COLLISION PREVENTION
ASSIST PLUS, ESP
®(Electronic Stability Program), PRE ‑SAFE®,
the HOLD function and hill start assist, for example, are also deac-
tivated.
ATTENTION ASSIST is deactivated.
GWARNING
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 stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction
display.
XDrive on carefully.
XVisit 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 lamps243
On-board computer and displays
Z
ProblemPossible causes/consequences andMSolutions
!
The yellow ABS warning
lamp is lit while the
engine is running.ABS is temporarily unavailable. BAS, COLLISION PREVENTION
ASSIST PLUS, ESP®, EBD (electronic brake force distribution),
PRE‑SAFE®, the HOLD function and hill start assist, for example,
are therefore also deactivated.
Possible causes are:
Rself-diagnosis is not yet complete.
Rthe on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
GWARNING
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 stabilize the vehicle.
There is a risk of an accident.
XCarefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
XObserve the additional display messages in the multifunction
display.
XDrive on carefully.
XVisit a qualified specialist workshop.
244Warning and indicator lamps
On-board computer and displays