
The sensors may not detect snow and
objects which absorb ultrasonic sources.
Ultrasonic sources, such as an automatic
car wash, a lorry's compressed-air brakes
or a pneumatic drill, could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on uneven terrain.
! Fold in the ball coupling if the trailer tow
hitch is not required. PARKTRONIC meas-
ures the minimum detection range to an
obstacle from the bumper, not the ball cou- pling.
PARKTRONIC is activated automatically when you:
R switch on the ignition
R shift the transmission to position D,Ror N
PARKTRONIC is deactivated at speeds above
18 km/h. It is reactivated at lower speeds.
PARKTRONIC is deactivated for the rear area when you establish an electrical connection
between your vehicle and a trailer.
Range of the sensors General notes
PARKTRONIC does not take into account
obstacles located:
R below the detection range, e.g. persons,
animals or objects
R above the detection range, e.g. overhang-
ing loads, tail sections or loading ramps of
goods vehicles :
Example: sensors in the front bumper,
left-hand side The sensors must be free of dirt, ice and
slush. Otherwise, they may not function cor-
rectly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y
page 425).
Front sensors Centre Approx. 100 cm
Corners Approx. 60 cm Driving systems
255Driving and parking Z

Rear sensors
Centre Approx. 120 cm
Corners Approx. 80 cm
Minimum distance
Centre Approx. 20 cm
Corners Approx. 15 cm
If there is an obstacle within this range, the
relevant warning displays light up and a warn- ing tone sounds. If the distance falls below
the minimum, the distance may no longer be
shown.
Warning displays :
Segments on the left-hand side of the
vehicle
; Segments on the right-hand side of the
vehicle
= Segments showing operational readiness
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is in the
instrument cluster. The warning display for
the rear area is located on the roof lining in
the rear compartment.
The warning display for each side of the vehi-
cle is divided into five yellow and two red seg- ments. PARKTRONIC is operational if opera-
tional readiness indicator =lights up.
The selected transmission position and the
direction in which the vehicle is rolling deter- mine which warning display is active when the
engine is running. Transmission
position Warning display
D
Front area activated
R,
Nor the vehicle
is rolling back-
wards Rear and front areas
activated
P
No areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
From the:
R sixth segment onwards, you will hear an
intermittent warning tone for approx-
imately two seconds.
R seventh segment onwards, you will hear a
warning tone for approximately two sec-
onds. This indicates that you have now
reached the minimum distance.
Deactivating/activating PARKTRONIC :
Deactivates/activates PARKTRONIC
; Indicator lamp
If indicator lamp ;lights up, PARKTRONIC is
deactivated. Active Parking Assist is then also
deactivated.
i PARKTRONIC is automatically activated
when you turn the key to position 2in the
ignition lock. 256
Driving systemsDriving and pa
rking

Problems with PARKTRONIC
Problem
Possible causes/consequences and
M
MSolutions 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 been deactivated.
X If 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.
X Clean the PARKTRONIC sensors (Y page 425).
X Switch the ignition back on. The problem may be caused by an external source of radio or
ultrasound waves.
X See 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 (Y page 254).
Important safety notes Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that no persons, animals or
objects are in the manoeuvring range.
When PARKTRONIC is deactivated, Active
Parking Assist is also unavailable. For vehicles with the trailer tow hitch folded
out, the minimum length for parking spaces is
slightly longer.
If you have attached a trailer to your vehicle,
you should not use Active Parking Assist.
Once the electrical connection is established
between your vehicle and the trailer, Active
Parking Assist is no longer available.
PARKTRONIC is deactivated for the rear area. G
WARNING
While parking or pulling out of a parking
space, the vehicle swings out and can drive
onto areas of the oncoming lane. This could
cause you to collide with other road users.
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 kerbs slowly and not at a Driving systems
257Driving and parking Z

Important safety notes
G
WARNING
Blind Spot Assist does not react to vehicles:
R overtaken too closely on the side, placing
them in the blind spot area
R when the difference in the speed of
approach and overtaking is too great
As a result, Blind Spot Assist cannot warn
drivers in these situations. There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and maintain a safe distance at the side
of the vehicle.
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.
Radar sensors
The radar sensors for Blind Spot Assist are
integrated into the rear bumper. Make sure
that the bumpers are free from dirt, ice or
slush. 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 radar sensors checked at a qualified spe-
cialist workshop. Blind Spot Assist may no
longer work properly.
Monitoring range
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or obscured sensors
R poor visibility, e.g. due to fog, heavy rain,
snow or spray
R narrow vehicles, e.g. motorcycles or bicy-
cles
R very wide lanes
R narrow lanes
R vehicles not driving in the middle of their
lane
R barriers or other road boundaries Vehicles in the monitoring range are then not
indicated. Blind Spot Assist monitors the area up to
3.0 mbehind your vehicle and directly next to
your vehicle, as shown in the diagram.
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 edge of
their lane nearest your vehicle.
Due to the nature of the system:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders
R warnings may be interrupted when driving
alongside long vehicles, for example lor-
ries, for a prolonged time Driving systems
277Driving and parking Z

Activating/deactivating Lane Keeping
Assist X
To activate: press button ;.
Indicator lamp :lights up. The Lane
Lane
Keeping Assist on
Keeping Assist on message appears in
the multifunction display. If all conditions
have been satisfied, there may be a warn-
ing.
If you drive at speeds above 60 km/h and
lane markings are detected, the lines in the assistance graphic display (Y page 326)
are shown in green. Lane Keeping Assist is
ready for use.
X To deactivate: press button;.
Indicator lamp :goes out. Lane Keeping
Assist is deactivated. The Lane Keeping
Lane Keeping
Assist off Assist off message appears in the mul-
tifunction display.
Selecting Standard or Adaptive setting
X In the Assistance
Assistance menu on the on-board
computer, select the Lane Keeping
Lane Keeping
Assist
Assist function (Y page 329).
X Select Standard
Standard orAdaptive
Adaptive.
Standard
When Standard Standard is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
Adaptive When
Adaptive
Adaptive is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane marking, the system detects certain condi-
tions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend
R the road has very wide lanes, e.g. a motor-
way
R the system detects solid lane markings
The warning vibration occurs later if:
R the road has narrow lanes
R you cut the corner on a bend Driving Assistance Plus package
General notes The Driving Assistance PLUS package con-
sists of DISTRONIC PLUS (Y
page 236), Active
Blind Spot Assist (Y page 280) and Active
Lane Keeping Assist (Y page 283).
Active Blind Spot Assist General notes
Active Blind Spot Assist monitors the areas
on either side of the vehicle that are not visi-
ble to the driver with two lateral, rear-facing
radar sensors. A warning display in the exte-
rior mirrors draws your attention to vehicles
detected in the monitored area. If you then 280
Driving systemsDriving and pa
rking

switch on the corresponding turn signal to
change lanes, you will also receive a visual
and audible collision warning. If a risk of side impact is detected, corrective braking may
help you avoid a collision. Active Blind Spot
Assist evaluates the free space in the direc-
tion of travel and to the side before making a course-correcting brake application. For this,Active Blind Spot Assist uses the forward-
facing radar sensors.
Active Blind Spot Assist supports you from a
speed of approximately 30 km/h.
Important safety notes
Active Blind Spot Assist is only an aid and is
not a substitute for attentive driving. G
WARNING
Active Blind Spot Assist does not react to
vehicles:
R overtaking too closely on the side, placing
them in the blind spot area
R if the difference in the speed of approach
and overtaking is too great
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 pay careful attention to the traffic sit-
uation and maintain a safe distance at the side of the vehicle.
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 trim 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 function properly. Monitoring range G
WARNING
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 to the side for other traffic or obstacles. Active Blind Spot Assist monitors the area up
to 3.0 mbehind your vehicle and directly next
to your vehicle, as shown in the diagram.
The detection of vehicles may be impaired in the case of:
R dirt on the sensors or obscured sensors
R poor 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 edge of
their lane nearest your vehicle. Driving systems
281Driving and parking Z

If a course-correcting brake application
occurs, red warning lamp :flashes in the
exterior mirror and a dual warning tone
sounds. In addition, 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-
correcting brake application may be interrup-
ted at any time if you steer slightly in the
opposite direction or accelerate.
The course-correcting brake application is
available in the speed range between
30 km/h and 200 km/h.
Either a course-correcting brake application
appropriate to the driving situation, or none at all, may occur if:
R there are vehicles or obstacles, e.g. crash
barriers, on both sides of your vehicle
R a vehicle approaches too closely on the
side
R you have adopted a sporty driving style with
high cornering speeds
R you clearly brake or accelerate
R a driving safety system intervenes, such as
ESP ®
or PRE-SAFE ®
Brake
R ESP ®
is deactivated
R a loss of tyre pressure or a defective tyre is
detected Activating Active Blind Spot Assist
X Make sure that Active Blind Spot Assist is
activated in the on-board computer
(Y page 328).
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately 1.5 seconds. Grey radar waves propagating backwards
appear next to the vehicle in the assistance
display in the multifunction display.
Towing a trailer
If you couple up a trailer, make sure that you have correctly established the electrical con-
nection. This can be accomplished by check- ing the trailer lighting. Active Blind Spot Assist
is then deactivated. The radar waves next to
the vehicle are hidden in the assistance dis-
play. The Active
Active Blind BlindSpot
SpotAssist
Assist not
not
available
available when
whentowing
towing a
atrailer
trailer See
See
Owner's Manual
Owner's Manual message appears 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-
screen. 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 Driving systems
283Driving and parking Z

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 an accident nor override the laws of
physics. Active Lane Keeping Assist cannot
take account of road and weather conditions.
It may not detect 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 lane.
Active Lane Keeping Assist cannot continu-
ously keep your vehicle in its lane. G
WARNING
Active Lane Keeping Assist cannot always
clearly detect lane markings.
In such cases, Active Lane Keeping Assist
can:
R give an unnecessary warning and then
make a course-correcting brake application
to the vehicle
R neither give a warning nor 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 func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflection from other vehicles
(e.g. if the road surface is wet)
R the windscreen is dirty, misted up, dam-
aged or covered, for instance by a sticker,
in the vicinity of the camera R
the radar sensors in the front or rear bump-
ers or the radiator trim are dirty, e.g.
obscured by snow
R no or several, unclear lane markings are
present for one lane, e.g. in a construction
area
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are highly variable shade conditions
on the road
If no vehicle is detected in the adjacent lane
and broken lane markings are detected, no
lane-correcting brake application is made.
Warning vibration through the steering
wheel
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 steer-
ing wheel for up to 1.5 seconds.
Lane-correcting brake application
If you leave your lane under certain circum-
stances, the vehicle will brake briefly on one
side. This is intended to help you return the
vehicle to the original lane. G
WARNING
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. 284
Driving syste
msDriving and parking