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Always pay careful attention to the traffic
situation and be ready to brake. G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
R intervene unnecessarily
R not intervene
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake. Terminate
the intervention in a non-critical driving sit-
uation.
In particular, the detection of obstacles can be
impaired in the case of:
R dirt on the sensors or anything else covering
the sensors
R snow or heavy rain
R interference from other radar sources
R strong radar reflections, for example, in
parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause Adaptive Brake Assist to inter-
vene.
If you fail to adapt your driving style, Adaptive
Brake Assist can neither reduce the risk of
accident nor override the laws of physics.
Adaptive Brake Assist cannot take into
account road, weather or traffic conditions.
Adaptive Brake Assist is only an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, braking in good time
and for staying in your lane.
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 collisions
at slow speeds where there is no visible dam-
age to the front of the vehicle.
If you change wheel size, make sure they cor-
respond to the correct wheel size category
(Y page
278). If the category is changed with- out recoding the control units in the vehicle,
the functioning of Adaptive Brake Assist may
be impaired. COLLISION PREVENTION ASSIST
may then detect a malfunction and switch
itself off.
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.
Operation With the help of the radar sensor system,
Adaptive Brake Assist can detect obstacles
that have been in the path of your vehicle for
an extended period of time. Adaptive Brake
Assist does not react to stationary obstacles.
If Adaptive Brake Assist detects a risk of colli-
sion with a vehicle traveling in front or with a
stationary obstacle, the system calculates the
braking force necessary to avoid this collision.
If you apply the brakes forcefully, Adaptive
Brake Assist will automatically increase the
braking force to a level suitable for the traffic
conditions.
X Brake until the distance to the obstacle
increases and the risk of a collision passes.
ABS prevents the wheels from locking.
The brakes function as usual again if:
R you release the brake pedal
R there is no longer any danger of a collision
R no obstacle is detected in front of your vehi-
cle
Braking assistance is then ended. Blind Spot Assist
General notes Blind Spot Assist monitors the areas on either
side of the vehicle that are not visible to the
driver with two lateral, rear-facing radar sen-
sors in the bumper. It supports you from
speeds of approximately
20 mph (30 km/h). A
warning display in the exterior mirrors draws
your attention to vehicles detected in the
monitored area. If you then switch on the cor-
responding turn signal to change lane, you will
also receive an optical and audible collision
warning. Driving systems
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Important safety notes
G
WARNING
Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R vehicles which approach with a large
speed differential and overtake your vehi-
cle
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk
of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
Blind Spot Assist is only an aid. It may fail to
detect some vehicles and is no substitute for
attentive driving. Always ensure that there is
sufficient distance to the side for other road
users and obstacles.
In particular, the detection of obstacles can be
impaired in the case of:
R dirt on the sensors or anything else covering
the sensors
R fog, heavy rain or snow
R narrow vehicles, e.g. motorcycles or bicy-
cles
R very wide lanes
R narrow lanes
R vehicles not driving in the middle of their
lane
R barriers or other road boundaries
Vehicles in the monitoring range are then not
indicated.
i USA only:
This device has been approved by the FCC
as a "Vehicular Radar System". The radar
sensor is intended for use in an automotive
radar system only. Removal, tampering, or
altering of the device will void any warran-
ties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user’s authority to operate
the equipment. Monitoring range of the sensors
Blind Spot Assist monitors the area shown in
the diagram up to
118 in (3 m) behind and
directly next to your vehicle.
If the lanes are narrow, vehicles driving in the
lane beyond the lane next to your vehicle may
be indicated, especially if the vehicles are not
driving in the middle of their lane. This may be
the case if the vehicles are driving on the inner
side of their lane.
Due to the nature of the system:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
R warnings may be interrupted when driving
alongside long vehicles, e.g. trucks, for a
prolonged time.
The two sensors for Blind Spot Assist are inte-
grated into the sides of the rear bumper. Make
sure that the bumper is free of dirt, ice or
slush in the vicinity of the sensors. The radar
sensors must not be covered, for example by
rear-mounted cycle racks or overhanging
loads. Following a severe impact or in the
event of damage to the bumper, have the func-
tion of the radar sensors checked at a quali-
fied specialist workshop. Blind Spot Assist
may otherwise not work properly. 152
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Warning display
Blind Spot Assist is not active at speeds below
approximately
20 mph (30 km/h). Vehicles in
the monitoring range are then not indicated.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
approximately 20 mph (30 km/h), warning
lamp : lights up red in the exterior mirror on
the corresponding side. Warning lamp :
always lights up when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (11 km/h).
If you select reverse gear, Blind Spot Assist is
inactive.
The intensity of warning lamps : depends on
the brightness of the ambient light and is con-
trolled automatically.
Collision warning If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the cor-
responding turn signal, a double warning tone
sounds once. The warning lamp in the corre-
sponding exterior mirror flashes. If the turn
signal remains on, detected vehicles are indi-
cated by the flashing of the warning lamp in
the exterior mirror. There are no further warn-
ing tones.
Activating Blind Spot Assist X
Make sure that Blind Spot Assist is activa-
ted in the on-board computer (Y page
191).
X Turn the key to position 2 in the ignition
lock.
The warning lamps in the exterior mirrors
light up for approximately
1.5 seconds. Status indicators in the status overview submenu
If Blind Spot Assist is activated, the display
shows symbol : in the Status Overview
submenu of the on-board computer
(Y page
189). If you are driving faster than
20 mph (30 km/h), the symbol also shows
radar waves ; between the two vehicles.
Blind Spot Assist is then ready for use.
Towing a trailer If you attach a trailer, make sure that you have
correctly established the electrical connection.
This can be accomplished by checking the
trailer lighting. Blind Spot Assist is then deacti-
vated and the Blind Spot Assist Cur‐
rently Unavail. See Operator's Manual
message appears in the display. Lane Keeping Assist
General notes Lane Keeping Assist monitors the area in front
of your vehicle by means of camera : which
is mounted at the top of the windshield. Lane
Keeping Assist detects lane markings on the
road and can warn you before you leave your
lane unintentionally.
This function is available in the range between
40 mph (60 km/h
) and 125 mph (200 km/h).
A warning may be given if a front wheel
touches a lane marking. It will warn you by Driving systems
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means of intermittent vibration through the
steering wheel for up to
1.5 seconds.
Important safety notes G
WARNING
Lane Keeping Assist cannot always clearly
detect lane markings.
In such cases, Lane Keeping Assist can:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, espe-
cially if Lane Keeping Assist alerts you. G
WARNING
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
Keeping Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
accident nor override the laws of physics.
Lane Keeping Assist cannot take into account
road, weather or traffic conditions. Lane Keep-
ing Assist is only an aid. You are responsible
for the distance to the vehicle in front, for
vehicle speed, braking in good time and for
staying in your lane.
Lane Keeping Assist does not keep your vehi-
cle in its lane.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflection from other vehicles
(e.g. if the road surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R there are no lane markings, or several
unclear lane markings for one lane, e.g.
around construction sites 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
short and thus the lane markings cannot be
detected
R the lane markings change quickly, e.g. lanes
branch off, cross one another or merge
R the road is narrow and winding
R there are highly variable shade conditions
on the road
Deactivating and activating Lane Keep-
ing Assist X
Press the Ç button.
If the indicator lamp in the button lights up
and the display shows the Ç symbol in
the status area, Lane Keeping Assist is
switched on but not ready for use.
If you are driving with Lane Keeping Assist
activated at speeds above
40 mph
(60 km/h) and lane markings are detected,
the display shows the Ç symbol highligh-
ted in the status area. Lane Keeping Assist
is then ready for use. Status indicators in the status overview submenu
The display in the Status Overview submenu
of the on-board computer also shows the sta-
tus of Lane Keeping Assist
(Y page 189). If
Lane Keeping Assist is activated but not ready
for use, the display shows the lane markings in
the symbol as broken lines :. If Lane Keeping154
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Assist is ready for use, the lane markings in
the symbol are shown as solid lines
;.
Setting the sensitivity of Lane Keeping
Assist X
In the Assist. menu on the on-board com-
puter, select the Lane Keeping Assist:
function
(Y page 191).
X Select Standard or Adaptive.
In the Standard setting, no warning vibration
occurs if:
R you operate the turn signal in the corre-
sponding direction. In this event, the warn-
ings are suppressed for a certain period of
time.
R a driving safety system, such as ABS, BAS or
ESP ®
, intervenes or performs a control
action.
When Adaptive is selected, there is also no
warning vibration when: R you accelerate hard, e.g. kickdown.
R brake sharply.
R you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when neces-
sary and in good time if you cross the lane
marking, the system differentiates between
various conditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, such as a
highway.
R the system detects solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend. Alertness Assistant ATTENTION
ASSIST
General notes ATTENTION ASSIST helps you during long,
monotonous journeys such as on freeways and
interstate highways. It is active in the 40 mph
(
60 km/h) to 125 mph (200 km/h) range. If
ATTENTION ASSIST detects typical indicators of fatigue or increasing lapses in concentration
on the part of the driver, it suggests taking a
break.
Important safety notes ATTENTION ASSIST is only an aid. The system
may not always detect fatigue or lapses in
concentration until too late, or may not detect
them at all. ATTENTION ASSIST is not a substi-
tute for a well-rested and attentive driver.
The functionality of ATTENTION ASSIST is
restricted, and warnings may be delayed or
not occur at all:
R if the length of the journey is less than
approximately
30 minutes
R if the road condition is poor, e.g. if the sur-
face is uneven or if there are potholes
R if there is a strong side wind
R if you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
R if you are predominantly driving at a speed
below 40 mph (60 km/h) or above 125 mph
(200 km/h)
R if the time has been set incorrectly
R in active driving situations, such as when
you change lanes or change your speed
ATTENTION ASSIST is reset and starts assess-
ing your attention again when you continue
your journey if:
R you switch off the engine
R you take off your seat belt and open the
driver's door, e.g. for a change of drivers or
to take a break
Displaying the attention level Driving systems
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For vehicles with steering wheel buttons you
can have the current ATTENTION ASSIST
(Attention Level) assessment displayed.
X Select Status Overview in the Assist.
menu and display the attention level
(Y page
189).
The following information is displayed: R the length of the journey since the last
break.
R the attention level determined by ATTEN-
TION ASSIST, displayed in a bar display in
five levels from low to high.
R if ATTENTION ASSIST is unable to calculate
the attention level and cannot output a
warning, the System Passive message
appears in the display. The bar display is
then dimmed. This is the case, for example,
if you are predominantly driving at a speed
below
40 mph (60 km/h) or above 125 mph
(200 km/h).
Activating ATTENTION ASSIST X
Activating ATTENTION ASSIST with the on-
board computer:
R on vehicles without steering wheel but-
tons
(Y page 180)
R on vehicles with steering wheel buttons
(Y page 190)
For vehicles with steering wheel buttons,
the system determines the attention level of
the driver depending on the setting selec-
ted:
Standard: the sensitivity with which the
system determines the attention level is set
to normal.
Sensitive: the sensitivity is set higher. The
driver is warned earlier.
When ATTENTION ASSIST is switched on and
the vehicle engine is running: R on vehicles without steering wheel buttons,
the À indicator lamp in the instrument
cluster lights up
R on vehicles with steering-wheel buttons, the
display shows the À symbol:
- in the status area
- in the Status Overview of the Assist.
menu (Y page
189)
For vehicles with steering wheel buttons, if you
deactivate ATTENTION ASSIST, the system is
automatically re-activated when you start the engine. The system sensitivity then corre-
sponds to the last selection activated – stand-
ard or sensitive.
If you switch off ATTENTION ASSIST in a vehi-
cle without steering wheel buttons, the system
remains switched off even after you start the
engine. The status of the system after switch-
ing on the engine always corresponds to the
status last selected.
Warning in the display If the system detects tiredness or increasing
lapses in concentration, the warning
Atten‐
tion Assist: Take a Break! or Attent.
Asst: Take Break!is shown in the display.
An additional warning tone sounds.
X If necessary, take a break.
X Confirm the message by pressing the a
button on the steering wheel.
On long journeys, take regular breaks in good
time to allow yourself to rest. If you do not
take a break and ATTENTION ASSIST contin-
ues to detect increasing lapses in concentra-
tion, you will be warned again after
15 minutes
at the earliest. This will only happen if ATTEN-
TION ASSIST still detects typical indicators of
fatigue or increasing lapses in concentration. PARKTRONIC
General notes PARKTRONIC is an electronic parking aid. The
system is equipped with ultrasonic sensors in
the front and rear bumpers to monitor the area
around your vehicle. PARKTRONIC indicates
visually and audibly the distance between your
vehicle and an object.
Your vehicle features two separate sound
emitters with different frequencies for the
warning tones. The warning ranges in front of
and behind the vehicle are indicated by differ-
ent warning tones.
PARKTRONIC is activated automatically when
you:
R turn the key to position 2 in the ignition lock
R release the parking brake and
R move the selector lever to position D, N or R156
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PARKTRONIC is deactivated at speeds above
11 mph (18 km/h
). PARKTRONIC is reactiva-
ted at speeds below 10 mph (16 km/h).
Important safety notes PARKTRONIC is only an aid. It cannot replace
your own awareness of the immediate sur-
roundings. You are responsible for safe
maneuvering, parking and pulling away. Make
sure that there are no persons, animals or
objects in the maneuvering area while maneu-
vering and parking in/leaving parking spaces.
! Pay particular attention to obstacles above
or below the sensors when parking, such as
flower pots or trailer towbars. PARKTRONIC
does not recognize such objects when they
are in the immediate vicinity of the vehicle.
You could damage the vehicle or objects.
PARKTRONIC can suffer interference from:
R ultrasonic sources such as a truck's
compressed-air brakes, an automatic car
wash or a pneumatic drill
R attachments to the vehicle, e.g. rear
mounted racks
R number plates (vehicle license plates)
that are not affixed flat against the
bumper
R dirty or icy sensors
Remove a detachable trailer coupling if it is no
longer required. PARKTRONIC measures the
minimum detection range to an obstacle from
the bumper, not the ball coupling.
Range of the sensors PARKTRONIC does not account for obstacles
that are:
R beneath its detection range, e.g. persons,
animals or objects
R above its detection range, e.g. overhanging
loads, overhangs or loading ramps of trucks The sensors must be free of dirt, ice or slush.
Otherwise, they cannot function correctly.
Clean the sensors regularly, taking care not to
scratch or damage them (Y page
267).
Front sensors Center Approx. 39 in
(100 cm
) Corners Approx. 24 in
(60 cm
) Rear sensors
Center Approx. 47 in
(120 cm
) Corners Approx. 31 in
(80 cm
) Minimum distance
Center Approx. 8 in (20 cm)
Corners Approx. 8 in (20 cm)
If an obstacle is within this range, the corre-
sponding segments of the warning displays
light up and you hear a warning tone. If the
distance falls below the minimum, the dis- Driving systems
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tance from an obstacle may no longer be
shown.
Warning displays Front area warning display in center of dashboard
Rear area warning display on the dashboard
Rear area warning display in center of the head-
liner in the rear compartment.
:
Warning segments for the left side of the
vehicle
; Warning segments for the right side of the
vehicle
= Segments showing operational readiness
The warning displays show the distance
between the sensor and the obstacle. The warning display is divided into five yellow
and two red segments for each side of the
vehicle. PARKTRONIC is operational if opera-
tional readiness indicator = lights up.
There is a malfunction if only the red segments
of the warning display light up
(Y page 159).
The selected transmission position determines
whether the front and/or rear area is moni-
tored. Selector lever posi-
tion Monitoring
h
Front area
k or i Front and rear area
j
No areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle. In addi-
tion, warning tones are emitted.
When the distance to the obstacle is sufficient,
you will hear an intermittent warning tone.
When the distance to the obstacle is sufficient,
you will hear an intermittent warning tone.
When the minimum distance is reached, you
hear a continuous warning tone.
Roll-back warning Regardless of transmission position,
PARKTRONIC automatically monitors the area
behind the vehicle if the vehicle begins to roll
backwards, e.g. after stopping on an uphill gra-
dient.
Activating/deactivating PARKTRONIC X
Press the f button.
If PARKTRONIC is deactivated, the indicator
lamp in the switch lights up.158
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Driving and parking