
Obstructions and stationary vehicles
DISTRONIC PLUS does not brake for obsta-
cles or stationary vehicles. If, for example, the
detected vehicle turns a corner and reveals
an obstacle or stationary vehicle, DISTRONIC
PLUS will not brake for these.
Crossing vehicles
DISTRONIC PLUS may mistakenly detect
vehicles that are crossing your lane. Activat-
ing DISTRONIC PLUS at traffic lights with
crossing traffic, for example, could cause
your vehicle to pull away unintentionally.
DISTRONIC PLUS with Steering Assist
and Stop&Go Pilot
General notes
DISTRONIC PLUS with Steering Assist and
Stop&Go Pilot aids you in keeping the vehicle
in the center of the driving lane by means of
moderate steering interventions at speeds of
0 - 125 mph (0 - 200 km/h).
It monitors the area in front of your vehicle by
means of camera system :at the top of the
windshield.
At speeds of 0 - 37 mph (0 - 60 km/h),
Stop&Go Pilot focuses on the vehicle in front,
taking into account lane markings, e.g. when
following vehicles in a traffic jam.
At speeds of more than 37 mph (60 km/h)
Steering Assist focuses on detected lane
markings (left and right), and only on the vehi-
cle in front if lane markings are missing.
Steering Assist and Stop&Go Pilot do not pro-
vide any support if these conditions do not
exist.
DISTRONIC PLUS must be active in order for
the function to be available.
Important safety notes
If you fail to adapt your driving style,
DISTRONIC PLUS with Steering Assist and
Stop&Go Pilot can neither reduce the risk of
an accident nor override the laws of physics. It cannot take account of road, weather and
traffic conditions. DISTRONIC PLUS with
Steering Assist and Stop&Go Pilot is only an
aid. You are responsible for the distance to
the vehicle in front, for vehicle speed, for
190Driving systems
Driving and parking 

braking in good time and for staying in your
lane.
DISTRONIC PLUS with Steering Assist and
Stop&Go Pilot does not detect road and traf-
fic conditions. If you are following a vehicle
which is driving towards the edge of the road,
your vehicle could come into contact with the
curb or other road boundaries. Be particularly
aware of other road users, e.g. cyclists, that
are directly next to your vehicle.
Obstacles such as building site huts on the
lane or projecting out into the lane are not
detected.
An inappropriate steering intervention, e.g.
after intentionally driving over a lane marking,can be corrected at any time if you steer
slightly in the opposite direction.
DISTRONIC PLUS with Steering Assist and
Stop&Go Pilot cannot continuously keep your
vehicle in lane. In some cases, the steering
intervention is not sufficient to bring the vehi-
cle back to the lane. In such cases, you must
steer the vehicle yourself to ensure that it
does not leave the lane.
The support provided by the system can be
impaired 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
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
Rthe distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
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
The system is switc hed t
o passive and no lon-
ger assists you by performing steering inter-
ventions if:
Ryou actively change lane
Ryou switch on the turn signal
Rtake your hands off the steering wheel or do
not steer for a prolonged period of time
iSteering Assist and Stop&Go Pilot are
activated again automatically after a lane
change is completed.
Steering Assist and Stop&Go Pilot do not pro-
vide any support:
Ron very sharp corners
Rwhen a loss of tire pressure or a defective
tire has been detected and displayed
Pay attention also to the important safety
notes for DISTRONIC PLUS (
Ypage 182).
The steering interventions are carried out
with a limited steering moment. The system
requires the driver to keep his hands on the
steering wheel and to steer himself.
If you do not steer yourself or if you take your hands off the steering wheel for a prolonged
period of time, the system will first alert you
with a visual warning. A steering wheel sym-
bol appears in the multifunction display. If you
have still not started to steer and have not
taken hold of the steering wheel after five
seconds at the latest, a warning tone also
sounds to remind you to take control of the
vehicle. Steering Assist and Stop&Go Pilot are
switched to passive. DISTRONIC PLUS
remains active.
Driving systems191
Driving and parking
Z 

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 335).
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 199).
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 possibly indicate
parking spaces which are not suitable for
parking, for example:
Rwhere parking or stopping is prohibited
Rin front of driveways or entrances and exits
Ron unsuitable surfaces
202Driving systems
Driving and parking 

Top view with picture from the rear view
camera
:Yellow guide line at a distance of approx-
imately 13 ft (4.0 m) from the rear of the
vehicle
;Symbol for the split screen setting with
top view and rear view camera image
=Guide line for the maximum steering angle
?Yellow lane marking tires at current steer-
ing wheel angle (dynamic)
AYellow guide line for the vehicle width
including the exterior mirrors, for current
steering wheel angle (dynamic)
BVehicle center axle (marker assistance)
CYellow guide line at a distance of approx-
imately 3 ft (1.0m) fromthe rear of the
vehicle
DBumper
ERed guide line at a distance of approx-
imately 12 in (0.30 m) fromthe rear of the
vehicle
The guide lines are shown when the trans-
mission is in position R. The distance specifications only apply to
objects that are at ground level.
Top view with picture from the front cam-
era
:Symbol for the split screen setting with
top view and front camera image
;Yellow guide line at a distance of approx-
imately 13 ft (4.0
m)from the front of the
vehicle
=Yellow guide line for the vehicle width
including the exterior mirrors, for current
steering wheel angle (dynamic)
?Yellow lane marking tires at current steer-
ing wheel angle (dynamic)
ARed guide line at a distance of approx-
imately 12 in (0.30 m) from the front of the
vehicle
BYellow guide line at a distance of approx-
imately 3 ft (1.0 m) from the front of the
vehicle
214Driving systems
Driving and parking 

Important safety notes
ATTENTION ASSIST isonlyan aid to the
driv er.Itmight not always recogniz e fatigue
or increasing inattentiveness in time or fail to
recogniz e them at all. The system is not a
substitute for a well-rested and attentive
driv er.
The functionalit y of ATTENTION AS SIST is
restricted and warnings may bedelayed or
not occur at all:
Rifthe length of the journey isless than
appr oximately 30 minutes
Rifthe road cond ition ispoor, e.g. ifthe sur-
face isuneven or if there are potholes
Rifthere isa strong side wind
Rifyou have adopted a sporty driving style
wit h high cornering speeds or high rates of
acceleration
Rif you are predominantly driving slower
than 37 mph (60 km/h) or faster than
125 mph (200 km/h)
Rif you are driving with the active Steer
Assist of DI STRONIC PLUS
Rifthe time has been set incorrectly
Rin active driving situations, such as when
you change lanes or change your speed
The ATTENTION AS SISTtiredness assess-
ment isdeleted and restarted when continu-
ing the journey, if:
Ryou switch off the engine
Ryou 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
You can have current status information dis-
played inthe assistance menu (
Ypage 244)
of the on-board computer.
XSe lect the Assistance display for ATTEN-
TION AS SISTusing the on-board computer
(
Ypage 243).
The following information is displayed:
Rlength of the journey since the last break.
Rthe attention level determined byATTEN-
TION AS SIST,disp layed ina bar display in
five levels from high to low.
Rif ATTENTION AS SIST isunableto calculate
the attention level and cannot output a
warning, the System Passive
message
appears. The bar display then changes the
display, e.g. ifyou are driving at a speed
below 37 mph (60 km/h)or above 124 mph
(200 km/h) .
Activating ATTENTION ASSIST
XActivateATTENTION ASSIST usin gth eon -
boar dcomputer (
Ypage 246).
The system determine sth eattention level
of th edriver depending on th e setting
selected:
Standar dselected: thesensitivit ywit h
whic hth esystem determine sth eattention
level is set to normal.
Sensit iveselected: thesensitivit yis set
higher. The attention level detecte dby Atten-
tion As sistis adapted accordingly and th e
driver is warned earlier .
216Driving systems
Driving and parking 

Problems with Night View Assist Plus
ProblemPossible causes/consequences andMSolutions
The picture quality of
Night View Assist Plus
has deteriorated.The windshield is fogged up on the inside.
XFold down camera cover (Ypage 337).
XDefrost the windshield (Ypage 141).
The windshield is iced up.
XDe-ice the windshield (Ypage 141).
The windshield wipers are smearing the windshield.
XReplace the wiper blades (Ypage 131).
The windshield is smeared after the vehicle has been cleaned in a
car wash.
XClean the windshield (Ypage 335).
There is windshield chip damage in the camera's field of vision.
XReplace the windshield.
The pedestrian and ani-
mal recognition is not
available.The infrared camera in the radiator grill is dirty.
XUse a soft cloth and water to clean the infrared camera.
Driving Assistance PLUS package
General notes
The Driving Assistance PLUS package con-
sists of DISTRONIC PLUS (
Ypage 182), Active
Blind Spot Assist (
Ypage 222) and Active
Lane Keeping Assist (
Ypage 225).
Active Blind Spot Assist
General notes
Active Blind Spot Assist uses a radar sensor
system, pointed toward the rear of the vehi-
cle, to monitor the area to the sides of the
vehicle which the driver is unable to see. 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 lanes, you
will also receive a visual and audible collision
warning. If a risk of lateral collision is detec- ted, corrective braking may help you avoid a
collision. Before a course-correcting brake
application, Active Blind Spot Assist evalu-
ates the space in the direction of travel and at
the sides of the vehicle. For this, Active Blind
Spot Assist uses radar sensors which are
pointed in the direction of travel.
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
222Driving systems
Driving and parking 

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. 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.
iCanada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause harmful inter-
ference, and
2. This device must accept any interference received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the
device will void any warranties, and is not
permitted. 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 se nso
rs
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, e.g. by
bicycle racks or overhanging loads. 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 oth-
erwise 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.
Active Blind Spot Assist monitors the area up
to 10 ft (3.0 m) behind your vehicle and
directly next to your vehicle, as shown in the
diagram.
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 nar-
row vehicles, such as motorcycles or bicy-
cles, 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
driving in the middle of their lane. This may be
the case if there are vehicles at the inner edge of your lane.
Driving systems223
Driving an d parking
Z 

Due to the nature of the system:
Rwarnings may be issued in error when driv-ing close to crash barriers or similar solid
lane borders.
Rwarnings may be interrupted when driving
alongside particularly long vehicles, e.g.
trucks, for a prolonged time.
Warning display
:Warning display
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 corre-
sponding 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).
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
surroundings.
When Active Blind Spot Assist is activated,
gray radar waves propagating backwards
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 indicated by the flash-
ing of red warning lamp :. There are no fur-
ther warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of a
lateral 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.
224Driving system s
Driving an d parking