!If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations.
To prevent damage to the vehicle, deacti-
vate DISTRONIC PLUS and the HOLD func-
tion in the following or other similar situa-
tions:
Rwhen towing the vehicle
Rin the car wash
If you fail to adapt your driving style,
DISTRONIC PLUS can neither reduce the risk
of accident nor override the laws of physics.
DISTRONIC PLUS cannot take into account
the road, traffic and weather conditions.
DISTRONIC PLUS 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 your lane.
Do not use DISTRONIC PLUS:
Rin road and traffic conditions which do not
allow you to maintain a constant speed e.g.
in heavy traffic or on winding roads
Ron slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid
Rwhen there is poor visibility, e.g. due to fog,
heavy rain or snow
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can
be impaired if:
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
If DISTRONIC PLUS no longer detects a vehi- cle in front, DISTRONIC PLUS may unexpect-
edly accelerate the vehicle to the stored
speed. This speed may:
Rbe too high if you are driving in a filter lane
or an exit lane
Rbe so high in the right lane that you pass
vehicles driving on the left (left-hand drive
countries)
Rbe so high in the left lane that you pass
vehicles driving on the right (right-hand
drive countries)
If there is a change of drivers, advise the new
driver of the speed stored.
Cruise control lever
:To activate or increase speed
;To activate or reduce speed
=To deactivate DISTRONIC PLUS
?To activate at the current speed/last
stored speed
ATo set the specified minimum distance
Activating DISTRONIC PLUS
Activation conditions
In order to activate DISTRONIC PLUS, the fol-
lowing conditions must be fulfilled:
Rthe engine must be started. It may take up
to two minutes after pulling away before
DISTRONIC PLUS is operational.
Rthe electric parking brake must be
released.
RESP®must be active, but not intervening.
RActive Parking Assist must not be activa-
ted.
Rthe transmission must be in position D.
Driving systems185
Driving and parking
Z
you use wintertires (M+S tire s), with snow
chains if necessary.
PARKTRONIC
Important safety notes
PARKTRONIC is an electronic parking aid with ultrasonic sensors. It monitors the area
around your vehicle using six sensors in the
front bumper and six sensors in the rear
bumper. PARKTRONIC 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
Rshift the transmission to position D,Ror N
PARKTRONIC is deactivated at speeds above
11 mph (18 km/ h). It is reactivated at lower
speeds.
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)
The sensors must be free from dirt, ice or
slush. They can otherwise not function cor-
198Driving systems
Driving and parking
Problems with PARKTRONIC
ProblemPossible causes/consequences andMSolutions
Only the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is then
deactivated and the
indicator lamp on the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.
XIf problems persist, have PARKTRONIC checked at a qualified
specialist workshop.
Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is then
deactivated.The PARKTRONIC sensors are dirty or there is interference.
XClean the PARKTRONIC sensors (Ypage 348).
XSwitch the ignition back on.
The problem may be caused by an external source of radio or
ultrasound waves.
XSee if PARKTRONIC functions in a different location.
Active Parking Assist
General notes
Active Parking Assist is an electronic parking
aid with ultrasound. It measures the road on
both sides of the vehicle. A parking symbol
indicates a suitable parking space. Active
steering intervention and brake application
can assist you during parking and when exit-
ing a parking space. You may also use
PARKTRONIC (
Ypage 198).
Important safety notes
Active Parking Assist is merely an aid. It is not
a replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking
and exiting a parking space. Make sure that
no persons, animals or objects are in the
maneuvering range.
When PARKTRONIC is switched off, Active
Parking Assist is also unavailable.
GWARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
result in a collision with another road user.
There is a risk of an accident.
Pay attention to other road users. Stop the
vehicle if necessary or cancel the Active Park- ing Assist parking procedure.
!If unavoidable, you should drive over
obstacles such as curbs slowly and not at a
sharp angle. Otherwise, you may damage
the wheels or tires.
Active Parking Assist may also display spaces
not suitable for parking, e.g.:
Rwhere parking or stopping is prohibited
Rin front of driveways or entrances and exits
Ron unsuitable surfaces
Driving systems201
Driving and parking
Z
DrivingAssistance PLUS package
General notes
The Driving Assistanc ePLU Spackage con-
sists of DISTRONIC PLU S (
Ypage 183), Active
Blin dSpot Assis t (
Ypage 222) and Active
Lan eKeepin gAssis t (
Ypage 225).
Active Blind Spot Assist
General notes
Active Blin dSpot Assis tuses aradar sensor
system, pointe dtoward th erea rof th evehi-
cle, to monito rth eare ato th esides of th e
vehicle whic hth edriver is unable to see . A
warnin gdisplay in th eexterio rmirrors draws
your attention to vehicles detecte din th e
monitored area. If you then switch on th ecor-
respondin gturn signal to chang elane, you
will also receiv ean optical and audible warn -
ing. If aris kof latera lcollision is detected,
corrective braking may hel pyou avoid acol-
lision .Before acourse-correcting brake appli -
cation ,Active Blin dSpot Assis tevaluates th e
spac ein th edirection of trave land at th e
sides of th evehicle. Fo rthis, Active Blin dSpot
Assis tuses th eforward-facin gradar sensors.
Active Blin dSpot Assis tsupports you from a
speed of approximately 20 mph (30 km/h).
Important safet ynotes
Active Blin dSpot Assis tis only an aid and is
no t a substitute fo rattentive driving.
GWARNING
Active Blin dSpot Assis tdoe sno treact to :
Rvehicles overtaken to oclosely on th eside,
placin gthem in th eblin dspo tare a
Rvehicles whic happroac hwit h a larg espeed
differential and overtak eyour vehicle
As aresult ,Active Blin dSpot Assis tmay nei-
ther giv ewarnings no rinterven ein suc hsit -
uations. There is aris kof an accident.
Always observ eth etraffic condition scare-
fully, and maintain asaf elatera ldistance.
iUS Aonly: Thi sdevic ehas been approved
by th eFCC as a"Vehicular Radar System".
The radar sensor is intended fo ruse in an
automotive radar system only. Removal,
tampering, or altering of th edevic ewill void
any warranties ,and is no tpermitte dby th e
FCC. Do no ttampe rwith, alter, or use in
any non-approved way.
An yunauthorized modification to this
devic ecould void th euser's authorit yto
operat eth eequipment.
iCanada only: Thi sdevic ecomplies wit h
RSS-210 of Industry Canada. Operation is
subjec tto th efollowing tw oconditions:
1. Thi sdevic emay no tcaus eharmful inter-
ference ,and
2. Thi sdevic emus taccept any interfere
nce
re
ceived, includin ginterferenc ethat may
caus eundesired operation of th edevice.
Removal, tampering, or altering of th e
devic ewill void any warranties ,and is no t
permitted. Do no ttampe rwith, alter, or use
in any non-approved way.
An yunauthorized modification to this
devic ecould void th euser's authorit yto
operat eth eequipment.
Rada rsensor s
The Active Blin dSpot Assis tradar sensor sare
integrated into th efron tand rea rbumper s
and behin d acover in th eradiator trim. Mak e
sur ethat th ebumper sand th ecover in th e
radiator grill are free of dirt, ic eor slush. The
rea rsensor smus tno tbe covered, e.g. by
bicycl eracks or overhangin gloads. Following
a severe impact or in th eevent of damage to
th ebumpers, hav eth efunction of th eradar
sensor schecke dat aqualified specialist
workshop .Active Blin dSpot Assis tmay oth-
erwise no longer wor kproperly.
Monitoring area
GWARNING
Active Blind Spot Assis tdoe sno tdetec tall
traffic situation sand road users. There is a
ris kof an accident.
222Driving systems
Driving an d parking
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 253).
XTurn the SmartKey to position 2in the igni-
tion lock.
Warning lamps :in the exterior mirrors
light up red for approximately 1.5 second s.
Gray radar waves propagating backwards
appear next to the vehicle in the assistance
display in the multifunction display.
Active Lane Keeping Assist
General notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of multi-
function camera :at the top of the wind-
shield. Various different areas to the front,
rear and side of your vehicle are also moni-
tored 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 unintentionally. If
you do not react to the warning, a lane-cor-
recting application of the brakes can bring the
vehicle back into the original lane.
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 phys- ics. Active Lane Keeping Assist cannot take
account of road and weather conditions. It
may not recognize 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 your lane.
Active Lane Keeping Assist cannot continu-
ously 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 isa 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 ina non-critical driv-
ing situation.
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, damaged or covered, for instance by a sticker, in the
vicinity of the camera
Rthe radar sensors in the front or rear bump-
ers or the radiator trim are dirty, e.g.
obscured by snow
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
Driving systems225
Driving and parking
Z
Display messagesPossible causes/consequences andMSolutions
#
Check Brake Pad
Wear
The brak epads/lining shav ereached their wear limit.
US Aonly: th e$ red brak esystem warnin glamp is lit while th e
engin eis running .
XVisitaqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunc -
tioning.
XVisit aqualified specialist workshop .
Collision Preven‐
tionAssist Plu s
Currently Unavail‐
ableSee Opera‐
tor's Manual
COLLISION PREVENTION ASSIST PLU Sis temporarily no topera-
tional.
Possibl ecauses are:
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
COLLISION PREVENTION ASSIST PLU Sis 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 172).
XRestart th eengine.
Collision Preven ‐
tionAssist Plu s
Inoperative
COLLISION PREVENTION ASSIST PLU Sis temporarily inoperative
due to amalfunction .Adaptive Brake Assis tmay also hav efailed.
XVisit aqualified specialist workshop immediately.
PRE-SAFE Inopera‐
tiv eSee Opera‐
tor's Manual
Importan tfunction sof PRE-SAF E®havefailed. Al lother occupant
safet ysystems ,e.g. air bags ,remain available.
XVisit aqualified specialist workshop immediately.
Display messages26 5
On-board computer and displays
Z
Display messagesPossible causes/consequences andMSolutions
PRE-SAFEFunctions
Currently Limited
SeeOperator'sMan‐
ual
PRE ‑S AF E®PLU Sor PRE ‑SAFE®Brake is temporarily inoperative.
Possibl ecauses are:
Rfunction is impaire ddue to heav yrain or snow.
Rth erada rsensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radi osta-
tion sor other source sof electromagnetic radiation .
Rthesystem is outside th eoperating temperature range.
Rth eon-boar dvoltag eis to olow.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears.
PRE ‑S AF E
®PLU Sand PRE ‑S AF E®Brake are 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 172).
XRestart th eengine.
PRE-SAFEFunctions
Limite dSee Opera‐
tor's Manual
PRE ‑S AF E®PLU Sor PRE‑SAFE®Brake is unavailable due to amal-
function .BA SPLU Swit hCross-Traffic Assis tmay also hav efailed.
XVisit aqualified specialist workshop immediately.
266Display messages
On-board computer and displays
Display messagesPossible causes/consequences andMSolutions
Radar Sensors
Dirty See Opera‐
tor's Manual
At leaston eof th efollowing drivin gsystems or drivin gsafet ysys-
tems is temporarily restricted or inoperative:
RPRE-SAF E®PLUS
RPRE-SAF E®Brake
RCOLLISION PREVENTION ASSIST PLU S
RActive LaneKeepin gAssis t
RActive Blind Spot Assis t
RDISTRONIC PLUSwit hSteerin gAssis tand Stop&Go Pilo t
If th erada rsensor system in fron tis dirty, Active Blind Spot Assis t
will no tperform acourse-correcting brak eapplication .
Possibl ecauses are:
Rth esensor sin th eradiato rtrim and/o rin th ebumpers are dirty
Rth efunction of th edrivin gsystem or drivin gsafet ysystem is
impaire ddue to heav yrain or snow
A warnin gtone also sounds.
Whe nth ecauses state dabov eno longer apply, th edisplay mes -
sage disappears. Al ldrivin gsystems or drivin gsafet ysystems are
operative 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 172).
XSwitchof fth eengine.
XClean th esensor sin th efollowing location s (Ypage 348):
Rin theradiato rtrim
Rin th efron tbumper
Rin th erear bumper, particularl yin th emiddle of th erear
bumper
XRestart th eengine.
The display message disappears.
Display messages26 7
On-board computer and displays
Z