Monitoring range of the sensors
In particular, the detection of obstacles can be
impaired if:
Rthere is dirt on the sensors or anything else
covering the sensors
Rthere is poor visibility, e.g. due to fog, heavy
rain, snow or spray
Rthere are narrow vehicles, e.g. motorcycles or
bicycles
Rthe road has very wide lanes
Rthe road has narrow lanes
Ryou are not driving in the middle of the lane
Rthere are barriers or similar lane borders
Vehicles in the monitoring range are then not
indicated.
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 there are vehicles driving at the inner
edge of their lanes.
Due to the nature of the system:
Rwarnings may be issued in error when driving
close to crash barriers or similar solid lane
borders.
Rthe warning is canceled when driving for an
extended period next to long vehicles, such as
trucks.
The two radar sensors for Blind Spot Assist are
integrated 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 sensors
must not be covered, for example by cycle racks or overhanging loads. Following a severe impact
or in the event of damage to the bumpers, have
the function of the sensors checked at a quali-
fied specialist workshop. Blind Spot Assist may
otherwise not work properly.
Indicator and warning display
:Indicator lamp (yellow)
Warning lamp (red)
Blind Spot Assist is not active at speeds below
approximately 20 mph (30 km/h). Vehicles in
the monitoring range are then not indicated.
When Blind Spot Assist is activated, indicator
lamp :in the exterior mirrors lights up yellow
at speeds of up to 20 mph (30 km/h). At speeds
above 20 mph (30 km/h), the indicator lamp
goes out and Blind Spot Assist is operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp :on the correspond-
ing side lights up red. This warning is always
emitted 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 (12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. In this event, Blind Spot Assist
is no longer active.
The brightness of the indicator or warning lamps
is adjusted automatically according to the ambi-
ent light.
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. Red warning lamp :flashes. If the turn
signal remains on, detected vehicles are indica-
ted by the flashing of red warning lamp :.
There are no further warning tones.
Driving systems181
Driving and parking
Z
Switching on Blind Spot Assist
XMake sure that Blind Spot Assist
(Ypage 198) is activated in the on-board
computer.
XTurn the SmartKey to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors light
up red for approximately 1.5 seconds and
then turn yellow.
Lane Keeping Assist
General notes
Lane Keeping Assist monitors the area in front of
your vehicle with camera :, which is mounted
at the top of the windshield. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of
intermittent vibration in 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 an acci-
dent nor override the laws of physics. Lane
Keeping Assist cannot take into account the
road, traffic and weather conditions. Lane Keep- ing Assist is merely an aid. You are responsible
for the distance to the vehicle in front, for vehi-
cle speed, for braking in good time and for stay-
ing in your lane.
The Lane Keeping Assist does not keep the vehi-
cle in the 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 reflections (e.g. when 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, several or unclear lane markings
for a lane, e.g. in areas with road construction
work
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 small and the lane markings thus 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 strong shadows cast on the road
Switching on Lane Keeping Assist
XSwitch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
or Adaptive(Ypage 198).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
182Driving systems
Driving and parking
(Ypage 196) are shown in green. Lane Keep-
ing Assist is ready for use.
Standard
If Standardis selected, no warning vibration
occurs if:
Ryou have switched on the turn signals. In this
event, the warnings are suppressed for a cer-
tain period of time.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Adaptive
When Adaptiveis selected, no warning vibra-
tion occurs if:
Ryou have switched on the turn signals. In this
event, the warnings are suppressed for a cer-
tain period of time.
Ra driving safety system intervenes, e.g. ABS,
BAS or ESP®.
Ryou accelerate hard, e.g. kickdown.
Ryou brake hard.
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 recognizes certain 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, e.g. a highway.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Active Driving Assistance package
General notes
The Active Driving Assistance package consists
of DISTRONIC PLUS (Ypage 153), Active Blind
Spot Assist (Ypage 183) and Active Lane Keep-
ing Assist (Ypage 186).
Active Blind Spot Assist
General notes
Active Blind Spot Assist uses a radar sensor
system, pointed toward the rear of the vehicle,
to monitor the area to the sides of the vehicle
which the driver is unable to see. A warning dis- play in the exterior mirrors draws your attention
to vehicles detected in the monitored area. If
you then switch on the corresponding turn sig-
nal to change lane, you will also receive an opti-
cal and audible warning. If a risk of lateral colli-
sion is detected, corrective braking may help
you avoid a collision. Before a course-correcting
brake application, Active Blind Spot Assist eval-
uates the space in the direction of travel and at
the sides of the vehicle. For this, Active Blind
Spot Assist uses the forward-facing radar sen-
sors.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/h).
Important safety notes
Active Blind Spot Assist is only an aid and is not
a substitute for attentive driving.
GWARNING
Active 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, Active Blind Spot Assist may nei-
ther give warnings nor intervene in such sit-
uations. There is a risk of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
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. Removing, tampering with, or
altering the device will void any warranties,
and is not permitted by the FCC. Do not tam-
per 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.
Driving systems183
Driving and parking
Z
Warning display
:Warning display
Active Blind Spot Assist is not active at speeds
below approximately 20 mph (30 km/h). Vehi-
cles in the monitoring range are then not indi-
cated.
When Active Blind Spot Assist is activated, indi-
cator lamp :in the exterior mirrors lights up
yellow at speeds of up to 20 mph (30 km/h). At
speeds above 20 mph (30 km/h), the indicator
lamp goes out and Active Blind Spot Assist is
operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp :on the correspond-
ing side lights up red. This warning is always
given when a vehicle enters the blind spot mon-
itoring 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
(12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. Active Blind Spot Assist is not
operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
Visual and acoustic collision warning
If you switch on the turn signals to change lanes
and a vehicle is detected in the side monitoring
range, you receive a visual and acoustic collision
warning. You then hear a double warning tone
and red warning lamp :flashes. If the turn sig-
nal remains on, detected vehicles are indicated
by the flashing of red warning lamp :. There are
no further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a lat-
eral collision in the monitoring range, a course-
correcting brake application is carried out. This
is meant to assist you in avoiding a collision.
GWARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the
sides.
If a course-correcting brake application occurs,
red warning lamp :flashes in the exterior mir-
ror and a dual warning tone sounds. In addition,
display ;appears in the multifunction display
underlining the danger of a side collision.
In very rare cases, the system may make an
inappropriate brake application. An inappropri-
ate course-correcting brake application may be
interrupted at any time if you steer slightly in the
opposite direction or accelerate, for example.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (200 km/h).
Either no braking application, or a course-cor-
recting brake application adapted to the driving
situation occurs if:
Rthere are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle.
Ra vehicle approaches you too closely at the
side.
Ryou have adopted a sporty driving style with
high cornering speeds.
Ryou clearly brake or accelerate.
Ra driving safety system intervenes, e.g. ESP®
or PRE-SAFE®Brake.
Driving systems185
Driving and parking
Z
RESP®is switched off.
Ra loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist
XMake sure that Active Blind Spot Assist
(Ypage 198) is activated in the on-board
computer.
XTurn the SmartKey to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors light
up red for approximately 1.5 seconds and
then turn yellow.
Active Lane Keeping Assist
General notes
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunction
camera :at the top of the windshield. Various
different areas to the front, rear and side of your
vehicle are also monitored with the aid of the
radar sensor system. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally. If you do not react to the warning, a
lane-correcting application of the brakes can
bring the vehicle back into the original lane.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
For Active Lane Keeping Assist to assist you
when driving, the radar sensor system must be
operational
Important safety notes
If you fail to adapt your driving style, Active Lane
Keeping Assist can neither reduce the risk of
accident nor override the laws of physics. Active
Lane Keeping Assist cannot take account of
road and weather conditions. It may not recog- nize traffic situations. Active Lane Keeping
Assist is only 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
you
r lane.
Active Lane Keeping Assist cannot continuously
keep your vehicle in its lane.
GWARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
Rgive an unnecessary warning and then
make a course-correcting brake application
to the vehicle
Rnot give a warning or intervene
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep within the lane, especially
if Active Lane Keeping Assist alerts you. Ter-
minate the intervention in a non-critical driv-
ing situation.
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 reflections (e.g. when 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
Rthe radar sensors in the front or rear bumpers
or the radiator trim are dirty, e.g. obscured by
snow
Rthere are no, several or unclear lane markings
for a lane, e.g. in areas with road construction
work
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 small
and the lane markings thus cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cross one another or merge
186Driving system s
Driving an d parking
iDepending on your vehicle's equipment,
when the surround lighting and delayed
switch-off exterior lighting are on, the follow-
ing light up:
RParking lamps
RSide marker lamps
RSurround lighting in the exterior mirrors
Activating/deactivating the interior light-
ing delayed switch-off
If you activate the Light. Delayfunction, the
interior lighting remains on for 20 seconds after
you remove the SmartKey from the ignition lock.
XPress the =or; button on the steering
wheel to select the Sett.menu.
XPress the:or9 button to select the
Lightssubmenu.
XPress ato confirm.
XPress the :or9 button to select the
Light. Delayfunction.
When the Light. Delayfunction is activa-
ted, the vehicle interior is displayed in orange
in the multifunction display.
XPress the abutton to save the setting.
Vehicle
Activating/deactivating the automatic
door locking mechanism
XPress the =or; button on the steering
wheel to select the Sett.menu.
XPress the:or9 button to select the
Vehiclesubmenu.
XPress ato confirm.
XPress the :or9 button to select the
Auto. Door Locksfunction.
If the Auto.DoorLocksfunction is switched
on, the multifunction display shows the vehi-
cle's doors in orange.
XPress the abutton to save the setting.
If you activate the Auto.
DoorLocksfunction,
the vehicle is centrally locked above a speed of
around 9 mph (15 km/h).
For further information on the automatic locking feature, see (
Ypage 79).
Activating/deactivating the acoustic
locking verification signal
If you switch on the AcousticLockfunction, an
acoustic signal sounds when you lock the vehi-
cle.
XPress the =or; button on the steering
wheel to select the Sett.menu.
XPress the:or9 button to select the
Vehiclesubmenu.
XPress ato confirm.
XPress the :or9 button to select the
Acoustic Lockfunction.
If the Acoustic Lockfunction is activated,
the & symbol in the multifunction display
lights up orange.
XPress the abutton to save the setting.
Convenience
Activating/deactivating the EASY-
ENTRY/EXIT feature
GWARNING
When the EASY-ENTRY/EXIT feature adjusts
the steering wheel, you and other vehicle
occupants – particularly children – could
become trapped. There is a risk of injury.
While the EASY-ENTRY/EXIT feature is mak-
ing adjustments, make sure that no one has
any body parts in the sweep of the steering
wheel.
If somebody becomes trapped:
Rpress one of the memory function position
buttons, or
Rmove the switch for steering wheel adjust-
ment in the opposite direction to that in
which the steering wheel is moving.
The adjustment process is stopped.
XPress the =or; button on the steering
wheel to select the Sett.menu.
XPress the:or9 button to select the
Conveniencesubmenu.
XPress ato confirm.
200Menus and submenus
On-board computer and displays
XUsing:or9, select the EasyEntry/Exitfunction.
If the EasyEntry/Exitfunction is activated,
the vehicle steering wheel is displayed in
orange in the multifunction display.
XPress the abutton to save the setting.
Further information on the EASY-ENTRY/EXIT
feature (
Ypage 104).
Switching the belt adjustment on/off
XPress the =or; button on the steering
wheel to select the Sett.menu.
XPress the:or9 button to select the
Conveniencesubmenu.
XPress ato confirm.
XPress the :or9 button to select the
Belt Adjustmentfunction.
When the Belt Adjustmentfunction is acti-
vated, the seat belt is displayed in orange in
the multifunction display.
XPress the abutton to save the setting.
For further information on belt adjustment, see
(
Ypage 45).
Switching the fold-in mirrors when lock-
ing feature on/off
This function is only available when the vehicle is
equipped with the electrical fold-in function.
When you switch on the Auto. Mirror Fold‐
ingfunction, the exterior mirrors are folded in
when the vehicle is locked. If you unlock the
vehicle and then open the driver's or front-
passenger door, the exterior mirrors fold out
again.
XPress the =or; button on the steering
wheel to select the Settingsmenu.
XPress the:or9 button to select the
Conveniencesubmenu.
XPress ato confirm.
XPress the :or9 button to select the
Auto. Mirror Foldingfunction.
If the Auto. Mirror Foldingfunction is
switched on, the multifunction display shows
the vehicle's exterior mirror in orange.
XPress the abutton to save the setting.
If you have switched on the Auto. MirrorFoldingfunction and you fold in the exterior
mirrors by pressing button :, the exterior mir-
rors will not fold out automatically (
Ypage 106).
You can then only fold out the exterior mirrors
using button :.
Restoring the factory settings
XPress the=or; button on the steering
wheel to select the Sett.menu.
XPress the:or9 button to select the
Factory Settingsubmenu.
XPress ato confirm.
The Reset All Settings?function
appears.
XPress the :or9 button to select Noor
Yes.
XPress ato confirm the selection.
If you have selected Yesand confirmed, the
multifunction display shows a confirmation
message.
For safety reasons, the Day Lights
function in
the Lightssubmenu is only reset if the vehicle
is stationary.
Menus and submenus201
On-board computer and displays
Z
Display messagesPossible causes/consequences andMSolutions
The HOLD function is deactivated. Whenth ebrak epedal is firmly
depressed, an activation condition is no tfulfilled .
A warning tone also sounds.
XChec kth eactivation condition sfor th eHOLD function
(Ypage 162).
Lan eKeepin gAssistCurrently Unavaila‐ble See Operator' sManualorActive Lan eKeepingAssist Cur ‐rently UnavailableSee Operator' sMan ‐ual
LaneKeepin gAssis tor Active Lan eKeepin gAssis tis deactivated and
temporarily inoperative.
Possibl ecauses are:
Rth ewindshield in th ecamera' sfield of vision is dirty.
Rvisibilit yis impaire ddue to heav yrain ,snow or fog .
Rthere havebeen no lan emarking sfor an extended period.
Rth elan emarking sare worn, dark or covered, e.g. by dir tor snow.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Lan eKeepin gAssis tor Active Lan eKeepin gAssis tis operational
again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 144).
XClean th ewindshield.
Lan eKeepin gAssistInoperativeorActiveLan eKeepin gAssistInoperative
LaneKeepin gAssis tor Active Lan eKeepin gAssis tis defective.
XVisit aqualified specialist workshop .
Blind SpotAssistCurrently Unavaila‐ble See Operator' sManualorActiveBlind Spo tAssistCurrently Unavaila‐ble See Operator' sManual
Blind Spot Assistor Active Blind Spot Assis tis temporarily inoperative.
Possibl ecauses are:
Rth eradar sensor system is outside th eoperating temperature
range.
Rth eradar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation .
The yellow 9indicator lamp salso ligh tup in th eexterio rmirrors.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Blind Spot Assis tor Active Blind Spot Assis tis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 144).
XRestart th eengine.
Display messages21 5
On-board computer and displays
Z