into account road, weather or traffic conditions.
The distance warning function 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 vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
If you change wheel size, make sure they corre- spond to the correct wheel size category
(
Ypage 279). If the category is changed without
recoding the control units in the vehicle, the
functioning of the distance warning feature may
be impaired. COLLISION PREVENTION ASSIST
may then detect a malfunction and switch itself
off.
Operation
XTo activate/deactivate: activate or deacti-
vate the distance warning function in the on-
board computer (
Ypage 187).
If the distance warning function of COLLISION
PREVENTION ASSIST is activated, the display
shows the Äsymbol:
Rin the header
Rin the Status Overviewof the Assist.menu (Ypage 186)
At speeds up to approx 20 mph (30 km/h) the
display in vehicles with Active Parking Assist
first shows the ístatus indicator. Only up to
a speed of about 20 mph (30 km/h) does the display show the Äsymbol instead of the
í status indicator.
The distance warning function can help you to
minimize the risk of a front-end collision with a
vehicle ahead or reduce the effects of such a
collision. With the help of the radar sensor sys-
tem, the distance warning function can detect
obstacles that are in the path of your vehicle for
an extended period of time. If the distance warn-
ing function detects that there is a risk of a col-
lision, you will be warned visually and, where
necessary, acoustically. Without your interven-
tion, the distance warning function cannot pre-
vent a collision.
The distance warning function issues a warning
at speeds:
Rfrom about 4 mph (7 km/h) if you approach a
vehicle traveling in front or a stationary vehi-
cle too quickly. The ·warning lamp in the instrument cluster then lights up and an inter-
mittent warning tone also sounds.
At speeds up to about 45 mph (70 km/h), the
system also detects stationary obstacles, for
example stopped or parked vehicles.
XBrake immediately until the distance from the
obstacle increases and the risk of a front-end
collision passes.
or
XTake evasive action, provided it is safe to do
so.
Adaptive Brake Assist
General notes
Adaptive Brake Assist evaluates the traffic sit-
uation with the help of the radar sensor system and can detect obstacles which have been in
your vehicle's path for an extended period of
time. From speeds above 4 mph (7 km/h), Adap-
tive Brake Assist aids you in braking during haz-
ardous situations.
Up to a speed of approximately 125 mph
(200 km/h), Adaptive Brake Assist is capable of
reacting to moving obstacles that have already
been detected as such at least once over the
period of observation.
Important safety notes
GWARNING
Adaptive Brake Assist does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rto stationary obstacles
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.
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
Driving systems147
Driving and parking
Z
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.
In particular, the detection of obstacles can be
impaired in the case of:
Rdirt on the sensors or anything else covering
the sensors
Rsnow or heavy rain
Rinterference from other radar sources
Rstrong radar reflections, for example, in park-
ing garages
Ra narrow vehicle traveling in front, e.g. a
motorbike
Ra 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 acci-
dent 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 vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.
If you change wheel size, make sure they corre- spond to the correct wheel size category
(
Ypage 279). If the category is changed without
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, Adap-
tive Brake Assist can detect obstacles that have been in the path of your vehicle for an extended
period of time. Ada
ptive Brake Assist does not
react to stationary obstacles. If Adaptive Brake
Assist detects a risk of collision with a vehicle
traveling in front or with a stationary obstacle,
the system calculates the braking force neces-
sary 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.
XBrake 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:
Ryou release the brake pedal
Rthere is no longer any danger of a collision
Rno obstacle is detected in front of your vehicle
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 sensors
in the bumper. It supports you from speeds of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your atten-
tion to vehicles detected in the monitored area.
If you then switch on the corresponding turn
signal to change lane, you will also receive an
optical and audible collision warning.
Important safety notes
GWARNING
Blind Spot Assist does not react to:
Rvehicles overtaken too closely on the side,
placing them in the blind spot area
Rvehicles which approach with a large speed
differential and overtake your vehicle
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk of
an accident.
148Driving systems
Driving and parking
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:
Rdirt on the sensors or anything else covering
the sensors
Rfog, heavy rain or snow
Rnarrow vehicles, e.g. motorcycles or bicycles
Rvery wide lanes
Rnarrow lanes
Rvehicles not driving in the middle of their lane
Rbarriers or other road boundaries
Vehicles in the monitoring range are then not
indicated.
iUSA 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 warranties, 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 driv-
ing 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:
Rwarnings may be issued in error when driving
close to crash barriers or similar solid lane
borders.
Rwarnings may be interrupted when driving
alongside long vehicles, e.g. trucks, for a pro-
longed 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-moun- ted cycle racks or overhanging loads. Following
a severe impact or in the event of damage to the
bumper, have the function of the radar sensors
checked at a qualified specialist workshop.
Blind Spot Assist may otherwise not work prop-
erly.
Driving systems149
Driving an d parking
Z
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 corre-
sponding turn signal, a double warning tone
sounds once. The warning lamp in the corre-
sponding exterior mirror flashes. If the turn sig-
nal remains on, detected vehicles are indicated
by the flashing of the warning lamp in the exte-
rior mirror. There are no further warning tones.
Activating Blind Spot Assist
XMake sure that Blind Spot Assist is activated
in the on-board computer (Ypage 187).
XTurn the key to position 2in 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 StatusOverviewsub-
menu of the on-board computer (Ypage 186). 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 deactivated
and the Blind Spot Assist Currently
Unavail. See Operator's Manualmessage
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 means of
150Driving systems
Driving and parking
intermittent vibration through the steering
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 Keep-
ing 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 Keeping 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 vehicle
in its lane.
The system may be impaired or may not function
if:
Rthere is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,
fog or spray
Rthere is glare, e.g. from oncoming traffic, the
sun or reflection from other vehicles (e.g. if
the road surface is wet)
Rthe windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity of the camera
Rthere are no lane markings, or several unclear
lane markings for one lane, e.g. around con-
struction sites
Rthe lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too short
and thus the lane markings cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cross one another or merge
Rthe road is narrow and winding
Rthere are highly variable shade conditions onthe road
Deactivating and activating Lane Keep -
ing Assist
XPress the Çbutton.
If the indicator lamp in the button lights up
and the display shows the Çsymbol 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 Çsymbol highlighted in the
status area. Lane Keeping Assist is then ready
for use.
Status indicators in the status overview submenu
The display in the Status Overviewsubmenu
of the on-board computer also shows the status
of Lane Keeping Assist (
Ypage 186). If Lane
Keeping Assist is activated but not ready for use,
the display shows the lane markings in the sym-
bol as broken lines :. If Lane Keeping Assist is
Driving systems151
Driving and parking
Z
ready for use, the lane markings in the symbol
are shown as solid lines;.
Setting the sensitivity of Lane Keeping
Assist
XIn theAssist.menu on the on-board com-
puter, select the Lane Keeping Assist:
function (Ypage 187).
XSelectStandardorAdaptive.
In the setting Standard
, no warning vibration
occurs if:
Ryou operate the turn signal in the correspond-
ing direction. In this event, the warnings are
suppressed for a certain period of time.
Ra 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:
Ryou accelerate hard, e.g. kickdown.
Rbrake sharply.
Ryou steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
Ryou 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 mark-
ing, the system differentiates between various
conditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, such as a high-
way.
Rthe system detects solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou 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 con-
centration until too late, or may not detect them
at all. ATTENTION ASSIST is not a substitute for
a well-rested and attentive driver.
The functionality of ATTENTION ASSIST is
restricted, and warnings may be delayed or not
occur at all:
Rif the length of the journey is less than approx-
imately 30 minutes
Rif the road condition is poor, e.g. if the surface
is uneven or if there are potholes
Rif there is a strong side wind
Rif you have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration
Rif you are predominantly driving at a speed
below 40 mph (60 km/h) or above 125 mph
(200 km/h)
Rif the time has been set incorrectly
Rin active driving situations, such as when you
change lanes or change your speed
ATTENTION ASSIST is reset and starts assessing
your attention again when you continue your
journey if:
Ryou switch off the engine
Ryou take off your seat belt and open the driv-
er's door, e.g. for a change of drivers or to
take a break
Displaying the attention level
For vehicles with steering wheel buttons you can
have the current ATTENTION ASSIST (Attention
Level) assessment displayed.
152Driving systems
Driving and parking
XSelectStatus Overviewin theAssist.menu and display the attention level
(Ypage 186).
The following information is displayed:
Rthe length of the journey since the last break.
Rthe attention level determined by ATTENTION
ASSIST, displayed in a bar display in five levels
from low to high.
Rif ATTENTION ASSIST is unable to calculate
the attention level and cannot output a warn-
ing, the System
Passivemessage appears in
the display. The bar display is then dimmed.
This is the case, for example, if you are pre-
dominantly driving at a speed below 40 mph
(60 km/h) or above 125 mph (200 km/h).
Activating ATTENTION ASSIST
XActivating ATTENTION ASSIST with the on-
board computer:
Ron vehicles without steering wheel buttons
(Ypage 177)
Ron vehicles with steering wheel buttons
(Ypage 187)
For vehicles with steering wheel buttons, the
system determines the attention level of the
driver depending on the setting selected:
Standard: the sensitivity with which the sys-
tem 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:
Ron vehicles without steering wheel buttons,
the À indicator lamp in the instrument
cluster lights up
Ron vehicles with steering-wheel buttons, the
display shows the Àsymbol:
-in the status area
-in the Status Overviewof the Assist.menu (Ypage 186)
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 corresponds
to the last selection activated – standard or sen-
sitive.
If you switch off ATTENTION ASSIST in a vehicle without steering wheel buttons, the system
remains switched off even after you start the engine. The status of the system after switching
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!orAttent.Asst: Take Break!is shown in the display.
An additional warning tone sounds.
XIf necessary, take a break.
XConfirm 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 continues to
detect increasing lapses in concentration, 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 vis-
ually and audibly the distance between your
vehicle and an object.
Your vehicle features two separate sound emit- ters with different frequencies for the warning
tones. The warning ranges in front of and behind
the vehicle are indicated by different warning
tones.
PARKTRONIC is activated automatically when
you:
Rturn the key to position 2in the ignition lock
Rrelease the parking brake and
Rmove the selector lever to position D,N or R
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). PARKTRONIC is reactivated
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 surround-
ings. You are responsible for safe maneuvering,
Driving systems153
Driving and parking
Z
Towing a trailer
PARKTRONIC detects a coupled trailer if your
vehicle is equipped with the corresponding elec-
trical installations for trailer towing.
PARKTRONIC is deactivated for the rear area
when you establish an electrical connectionbetween your vehicle and a trailer. If you use an
adapter for the socket, remove it from the
socket after detaching the trailer. Otherwise,
PARKTRONIC remains deactivated for the rear
area.
Problems with PARKTRONIC
ProblemPossible causes/consequences and
MSolutions
Only the red segments in
the PARKTRONIC warn-
ing displays are lit.
In addition, a warning
tone sounds for approx.
two seconds
PARKTRONIC is then
deactivated.
The indicator lamp of the
f button lights up
and the red segments in
the PARKTRONIC warn-
ing display go out.PARKTRONIC has malfunctioned and has switched itself off.
XIf problems persist, have PARKTRONIC checked at a qualified spe- cialist workshop.
The PARKTRONIC warn-
ing displays implausible
distances.
For example, all the seg-
ments may be lit even
though there is no obsta-
cle present.The PARKTRONIC sensors are dirty or iced up.
XClean the PARKTRONIC sensors (Ypage 268).
XTurn the key to position 2in the ignition lock.
The license plate or other parts attached near the sensors may not be
secured correctly.
XCheck the license plate and attachment parts near the sensors for
correct seating.
An external radio or ultrasonic source may be causing interference.
XCheck PARKTRONIC functions in a different location.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking
aid. The system uses ultrasound sensors to
measure the road on both sides of the vehicle
and indicates suitable parking spaces. It can
then actively steer and brake the vehicle to help
you to park and exit the parking space.
Active Parking Assist includes the PARKTRONIC
parking aid which indicates visually and audibly the distance between your vehicle and an
obstruction. To do this, PARKTRONIC uses the ultrasonic sensors of the Active Parking Assist
(
Ypage 153).
Important safety notes
Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. You are responsible for safe
maneuvering, parking and pulling away. Make
sure that no persons, animals or objects are in
the maneuvering range.
When you deactivate PARKTRONIC, Active Park-
ing Assist will also be deactivated.
156Driving system
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Driving an d parking