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.
Radar sensors
The Active Blind Spot Assist radar sensors are
integrated into the front and rear bumpers and
behind a cover in the radiator trim. Make sure
that the bumpers and the cover in the radiator
grill are free of dirt, ice or slush. The rear sensors
must not be covered, for example by cycle racks
or overhanging cargo. Following a severe impact
or in the event of damage to the bumpers, have
the function of the radar sensors checked at a
qualified specialist workshop. Active Blind Spot
Assist may otherwise no longer work properly.
Monitoring area
GWARNING
Active Blind Spot Assist does not detect all
traffic situations and road users. There is a
risk of an accident.
Always make sure that there is sufficient dis-
tance on the side for other traffic or obstacles.
At a distance of approximately 1.6 ft (0.5 m);
from the vehicle, Active Blind Spot Assist mon-
itors the area up to 10 ft (3 m) next to =and
behind :your vehicle, as shown in the picture. The detection of obstacles can be impaired in
the case of:
Rthere is dirt on the sensors or anything else
covering the sensors
Rpoor visibility, e.g. due to rain, snow or spray
Vehicles in the monitoring range are then not
indicated.
Active Blind Spot Assist may not detect narrow
vehicles, such as motorcycles or bicycles, or
may only detect them too late.
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 at the inner edge of
your 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 you are
driving alongside particularly long vehicles,
such as trucks, for a prolonged time.
Warning lamp
:Warning lamp
Active Blind Spot Assist is not operational 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 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).
Driving systems205
Driving and parking
Z
If you select the reverse gear, Active Blind Spot
Assist is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
When Active Blind Spot Assist is activated, gray
radar waves propagating backward appear next
to the vehicle in the assistance display in the
multifunction display. Above a speed of 20 mph
(30 km/h), the color of the radar waves in the
assistance display changes to green;. Active
Blind Spot Assist is then ready for use.
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 will then hear a double warning
tone and 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.
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 double warning tone sounds. In addi-
tion, a display underlining the danger of a side
collision appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may be interrupted at
any time by countersteering slightly or acceler-
ating.
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.
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 is
activated in the on-board computer
(
Ypage 223).
XSwitch on the ignition.
Warning lamps :in the exterior mirrors light
up red for approximately 1.5 seconds.
Gray radar waves propagating backwards
appear next to the vehicle in the assistance
graphic in the multifunction display ;.
Above a speed of 20 mph (30 km/h), the color
of the radar waves in the assistance display
changes to green ;. Active Blind Spot Assist
is then ready for use.
206Driving systems
Driving and parking
Active Lane Keeping Assist
Generalnotes
Active Lan eKeepin gAssis tmonitors th earea in
fron tof your vehicl eby mean sof multifunction
camera :at th eto pof th ewindshield. Various
differen tareas to th efront, rear and side of your
vehicl eare also monitore dwit hth eaid of th e
radar sensor system. Active Lan eKeepin g
Assis tdetects lan emarking son th eroad and
can warn you before you leav eyour lan eunin-
tentionally. If you do no treac tto th ewarning , a
lane-correcting application of th ebrakes can
bring th evehicl ebac kint oth eoriginal lane.
This function is available in th erange between
40 mph and 12 0mph (60 km/h and 20 0km/h).
Important safety notes
If you fail to adapt your drivin gstyle, Active Lan e
Keepin gAssis tcan neither reduce th eris kof an
acciden tno roverride th elaws of physics .Active
Lan eKeepin gAssis tcanno ttak eaccoun tof
road and weather conditions. It may no trecog-
niz etraffic situations. Active Lan eKeepin g
Assis tis only an aid. You are responsibl efor th e
distanc eto th evehicl ein front, for vehicl e
speed, for braking in goo dtime and for stayin gin
your lane.
Active Lan eKeepin gAssis tcanno tcontinuously
keep your vehicl ein it slane.
GWARNIN G
Active Lan eKeepin gAssis tcanno talways
clearly detec tlan emarkings.
In suc hcases, Active Lan eKeepin gAssis t
can :
Rgivean unnecessary warning and then
mak e acourse-correcting brak eapplication
to th evehicl e
Rnotgiv e a warning or interven e
There is aris kof an accident.
Always pay particular attention to th etraffic
situation and keep within th elane, especially
if Active Lan eKeepin gAssis talerts you. Ter -
minate th eintervention in anon-critical driv-
ing situation .
The system may be impaire dor may no tfunction
if:
Rthere is poor visibility, e.g. due to insufficien t
illumination of th eroad ,or due to snow, rain ,
fog or spray
Rthere is glare, e.g. from oncomin gtraffic, th e
sun or reflection from other vehicles (e.g. if
th eroad surfac eis wet )
Rthewindshield is dirty, fogged up, damaged or
covered, for instance by asticker, in th evicin-
it y of th ecamera
Rth eradar sensor sin th efron tor rear bumpers
or th eradiato rtrim are dirty, e.g. obscured by
snow
Rthere are no ,several or unclear lan emarking s
for alane, e.g. in areas wit hroad construction
wor k
Rthelan emarking sare wor naway, dark or cov-
ere dup, e.g. by dir tor snow
Rth edistanc eto th evehicl ein fron tis to osmall
and th elan emarking sthus canno tbe detec -
te d
Rth elan emarking schang equickly, e.g. lanes
branch off ,cross on eanother or merge
Rth eroad is narrow and windin g
Rthere are highly variable shad econdition son
th eroadway
If no vehicl eis detecte din th eadjacent lan eand
broke nlan emarking sare detected, no lane-cor-
recting brak eapplication is made .
Warning vibration in th esteering wheel
A warning may be given if afron twhee lpasses
ove r alan emarking .It will warn you by mean sof
intermittent vibration in th esteering whee lfor
up to 1. 5seconds.
Driving systems207
Driving and parking
Z
Lane-correcting brake application
If you leave your lane, under certain circumstan-
ces the vehicle will brake briefly on one side.
This is meant to assist you in bringing the vehicle
back to the original lane.
GWARNING
A lane-correcting brake application cannot
always bring the vehicle back into the original lane. There is a risk of an accident.
Always steer, brake or accelerate yourself,
especially if Active Lane Keeping Assist warns
you or makes a lane-correcting brake appli-
cation.
If a lane-correcting brake application occurs,
display :appears in the multifunction display.
The brake application also slightly reduces vehi-
cle speed.
A lane-correcting brake application can be made
after driving over a lane marking detected as
being solid or broken. Before this, a warning
must be given by means of intermittent vibration
in the steering wheel. In addition, a lane with
lane markings on both sides must be recog-
nized.
In the case of a broken lane marking being
detected, a lane-correcting brake application
can only be made if a vehicle has been detected
in the adjacent lane. Oncoming vehicles, over-
taking vehicles and vehicles in adjacent lanes
can be detected.
A further lane-correcting brake application can
only occur after your vehicle has returned to the
original lane.
No lane-correcting brake application occurs if:
Ryou clearly and actively steer, brake or accel-
erate.
Ryou cut the corner on a sharp bend.
Ryou have switched on the turn signal.
Ra driving safety system intervenes, e.g. ESP®,
PRE-SAFE®Brake or Active Blind Spot Assist.
Ryou have adopted a sporty driving style with
high cornering speeds or high rates of accel-
eration.
RESP®is switched off.
Rthe transmission is not in position h.
Ra loss of tire pressure or a defective tire has
been detected and displayed.
Ran obstacle has been detected in the lane in
which you are driving.
Active Lane Keeping Assist may not detect other
road users or traffic situations. An inappropriate
brake application may be interrupted at any time
if you:
Rsteer slightly in the opposite direction.
Rswitch on the turn signal.
Ryou brake or accelerate significantly.
A lane-correcting brake application is interrup-
ted automatically if:
Ra driving safety system intervenes, e.g. ESP®,
PRE-SAFE®Brake or Active Blind Spot Assist.
Rlane markings are no longer detected.
Activating/deactivating Active Lane
Keeping Assist
XTo activate: press button ;.
Indicator lamp :lights up. The Lane Keep‐
ing Assist Onmessage appears on the
multifunction display. If all conditions have
been satisfied, a warning or steering inter-
vention may be made.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphic
208Driving systems
Driving and parking
(Ypage 221) appear in green. Active Lane
Keeping Assist is ready for use.
XTo deactivate: press button;.
Indicator lamp :goes out. The Active Lane
Keeping Assist is deactivated. The Lane
Keeping Assist Offmessage appears on
the multifunction display.
Selecting Standard or Adaptive setting
XIn the DriveAssistmenu on the on-board
computer, select the Active Lane Keep‐
ing Assistfunction (Ypage 223).
XSelect settingStandardorAdaptive.
When Standardis selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this case,
the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
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.
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 freeway.
Rthe system detects solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes
Ryou cut the corner on a bend
Driving systems209
Driving and parking
Z
Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position j.
XVisitaqualified specialist workshop .
$(USAonly)
J(Canada only)
Check Brake Fluid
Level
There is no tenough brak efluid in th ebrak efluid reservoir .
In addition ,th e$ (USAonly) or J(Canada only) warning lamp
lights up in th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec tmay be impaired.
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th e$ red brak esystem warning lamp is lit while th e
engin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
ActiveBrakeAssistFunctionsCurrentlyLimitedSee Opera‐tor's Manual
Active Brake Assis tis temporarily inoperative.
Possibl ecauses are:
RThe radar sensor system is temporarily inoperative, e.g. due to
electromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation .
RThe system is outside th eoperating temperature range.
RThe on-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Active Brake 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 161).
XRestart th eengine.
236Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
LaneKeepin gAssistCurrently Unavaila‐ble See Operator' sManualorActiveLan eKeepin gAssistCurrently Unavaila‐ble See Operator' sManual
LaneKeepin gAssis tor Active Lan eKeepin gAssis tis deactivated and
temporarily inoperative.
Possibl ecauses are:
RThe windshield 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
RThe lan emarking sare wor naway, dark or covered up, 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 161).
XClean th ewindshield.
Lan eKeepin gAssistInoperativeor
ActiveLan eKeepin gAssist Inoperative
LaneKeepin gAssis tor Active Lan eKeepin gAssis tis malfunctioning .
XVisitaqualified 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:
RThe radar sensor system is outside th eoperating temperature
range.
RThe radar sensor system is temporarily inoperative, e.g. due to
electromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation .
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 161).
XRestart th eengine.
Blind Spo tAssistInoperativeor
Active Blind Spo t
Assist Inoperative
Blind Spot Assistor Active Blind Spot Assis tis malfunctioning .
XVisitaqualified specialist workshop .
ParkingPilot Can ‐celedThe driver's door is open .
XRepeat theparking gap measuremen tand parking process wit hth e
driver's door closed .
248Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
You touched themultifunction steering whee lwhile steering inter-
vention was active .
XWhilesteering intervention is active ,mak esur ethat th emultifunc-
tion steering whee lis no ttouched unintentionally.
The vehicl ehas started to skid and ES P®has intervened.
XUse theParking Pilo tagain later (Ypage 184).
ParkingPilot Inop‐erativ eParking Pilo tis malfunctioning or defective.
XFollow th einstruction sand helpful hints in th e"Problem swit h
Parking Assis tPARKTRONIC" section (Ypage 190).
If th emultifunction display still shows th edisplay message :
XVisitaqualified specialist workshop .
Parking Pilotis unavailable or malfunctioning .
XSwitchoff th eignition and restar tth eengine.
If th eParking Pilo tcontinues to be unavailable (the jsymbol does
no tappear in th emultifunction display):
XVisit aqualified specialist workshop .
ParkingPilot Fin ‐ishedThe vehicleis parked. Awarning tone also sounds.
The display message disappear sautomatically.
Traffi cSignAssistCurrently Unavaila‐ble See Operator' sManual
Traffic SignAssis tis temporarily inoperative.
Possibl ecauses are:
RThe windshield in th ecamera' sfield of vision is dirty.
RVisibilit yis impaire ddue to heav yrain ,snow or fog .
XClean thewindshield.
If th esystem detects that th ecamera is full yoperational, th edisplay
message disappears.
Traffic Sig nAssis tis operational again .
TrafficSignAssistInoperativeTraffic Sig nAssis tis malfunctioning .
XVisitaqualified specialist workshop .
ë
Off
The HOLD function is deactivated. The vehicl eis skidding.
A warning tone also sounds.
XReactivat eth eHOLD function later (Ypage 180).
The HOLD function is deactivated. Whe nth 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 179).
Distance Pilot OffDistanc ePilo tDISTRONI Cis deactivated (Ypage 176).
If it was no tdeactivated by th edriver , awarning tone also sounds.
Display messages249
On-board computer and displays
Z