
The support provided by the system can be
impaired 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 reflections (e.g. when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
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 strong shadows cast on the road
The system is switched to passive and no lon-
ger assists you by performing steering inter-
ventions if:
R you actively change lanes
R you switch on the turn signal
R take your hands off the steering wheel or do
not steer for a prolonged period of time
i After you have finished changing lanes,
Steering Assist and Stop&Go Pilot are auto- matically active again.
DISTRONIC PLUS Steering Assist does not
provide assistance:
R on very sharp corners
R when 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 (Y page 181).
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.
Activating Steering Assist and Stop&Go
Pilot
X Activate the DISTRONIC PLUS with Steer-
ing Assist and Stop&Go Pilot function using
the on-board computer (Y page 236).
The DTR+:
DTR+: Steering Steering Assistant
Assistant On
On mes-
sage appears in the multifunction display.
Steering Assist and Stop&Go Pilot are
active.
Information in the multifunction display If Steering Assist and Stop&Go Pilot are acti-
vated but not ready for a steering interven-
tion, steering wheel symbol :appears in
gray. If the system provides you with support by means of steering interventions, sym-
bol :is shown in green.
Deactivating Steering Assist and Stop&Go Pilot
X Deactivate the DISTRONIC PLUS with
Steering Assist and Stop&Go Pilot function
using the on-board computer
(Y page 236).
The DTR+: Steering Assistant Off DTR+: Steering Assistant Off
message appears in the multifunction dis- 190
Driving systemsDriving and parking

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 switched off.
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 321).
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. You may also
use PARKTRONIC (Y page 197).
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. 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
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:
R where parking or stopping is prohibited
R in front of driveways or entrances and exits
R on unsuitable surfaces 200
Driving systemsDriving and parking

COMAND, see the Digital Operator's Man-
ual.
X Engage reverse gear.
The rear view camera flap opens. The area
behind the vehicle is shown with guide lines
in the Audio 20 or COMAND display.
The image from the rear view camera is
available throughout the maneuvering
process.
To deactivate: the rear view camera deacti-
vates if you shift the transmission to Por after
driving forwards a short distance.
Messages in the Audio 20/COMAND
display The rear view camera may show a distorted
view of obstacles, show them incorrectly or
not at all. The rear view camera does not show
objects in the following positions:
R very close to the rear bumper
R under the rear bumper
R in the area immediately above the tailgate
handle
! Objects not at ground level may appear to
be further away than they actually are, e.g.:
R the bumper of a parked vehicle
R the drawbar of a trailer
R the ball coupling of a trailer tow hitch
R the rear section of an HGV
R a slanted post
Use the guidelines only for orientation.
Approach objects no further than the bot-
tom-most guideline. :
Yellow guide line at a distance of approx-
imately 13 ft (4.0 m) from the rear of the
vehicle
; White guide line without turning the steer-
ing wheel, vehicle width including the
exterior mirrors (static)
= 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) A
Yellow guide line at a distance of approx-
imately 3 ft (1.0m) from the rear of the
vehicle
B Vehicle center axle (marker assistance)
C Bumper
D Red 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. 206
Driving systemsDriving an
d parking

R
Top view with picture from the rear view
camera
R Top view with picture from the front cam-
era
Displays in the COMAND/Audio 20 dis-
play Important safety notes
The camera system may show a distorted
view of obstacles, show them incorrectly or
not at all. Obstacles are not shown by the
system in the following locations:
R under the front and rear bumpers
R very close to the front and rear bumpers
R in the area immediately above the tailgate
handle/trunk lid handle
R very close to the exterior mirrors
R in the transitional areas between the vari-
ous cameras in the virtual top view
! Objects not at ground level may appear to
be further away than they actually are, e.g.:
R the bumper of a parked vehicle
R the drawbar of a trailer
R the ball coupling of a trailer tow hitch
R the rear section of an HGV
R a slanted post
Use the guidelines only for orientation.
Approach objects no further than the bot-
tom-most guideline. 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)
A Yellow guide line for the vehicle width
including the exterior mirrors, for current
steering wheel angle (dynamic) B
Vehicle center axle (marker assistance)
C Yellow guide line at a distance of approx-
imately 3 ft (1.0 m) from the rear of the
vehicle
D Bumper
E Red guide line at a distance of approx-
imately 12 in (0.30 m) from the rear of the
vehicle
The guide lines are shown when the trans-
mission is in position R. Driving systems
211Driving and parking Z

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)
A Red guide line at a distance of approx-
imately 12 in (0.30 m) from the front of the
vehicle
B Yellow guide line at a distance of approx-
imately 3 ft (1.0 m) from the front of the
vehicle Top view and enlarged rear view :
Symbol for the split screen setting with
top view and rear view camera image
enlarged
; Red guide line at a distance of approx-
imately 12 in (0.30 m) from the rear of the
vehicle
This view assists you in estimating the dis-
tance to the vehicle behind you.
i This setting can also be selected as an
enlarged front view.
Top view with image from the side mirror cameras :
Symbol for the top view and forward-
facing side mirror camera setting
; Yellow guide line for the vehicle width
including the exterior mirrors (right side of
vehicle)
= Yellow guide line for the vehicle width
including the exterior mirrors (left side of
vehicle)
i You can also select the side mirror cam-
era setting for the rear-facing view. 212
Driving systemsDriving and parking

180° view
:
Symbol for the full screen setting with rear
view camera image
; Own vehicle
= PARKTRONIC warning displays
i 180° view can also be selected as front
view.
Select this view when you are driving out of an
exit and the view of crossing traffic is restric- ted, for example.
Exiting 360° camera display mode The 360° camera display is stopped
R when you select transmission position P, or
R when you are driving at moderate speeds
The previous display appears on the
COMAND/Audio 20 display. You can also
switch the display by selecting the &sym-
bol in the display and pressing 7the con-
troller to confirm. ATTENTION ASSIST
General notes ATTENTION ASSIST helps you during long,
monotonous journeys, such as on highways.
It is active in the 37 mph (60 km/h) to
125 mph (200 km/h) range. If ATTEN-
TION ASSIST detects typical indicators of fati-
gue or increasing lapses in concentration on
the part of the driver, it suggests taking a
break. Important safety notes ATTENTION ASSIST is only an aid to the
driver. It might not always recognize fatigue
or increasing inattentiveness in time or fail to
recognize them at all. The system is not a
substitute for a well-rested and attentive
driver.
The functionality of ATTENTION ASSIST is
restricted and warnings may be delayed or
not occur at all:
R if the length of the journey is less than
approximately 30 minutes
R if the road condition is poor, e.g. if the sur-
face is uneven or if there are potholes
R if there is a strong side wind
R if you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
R if you are predominantly driving at a speed
below 37 mph (60 km/h) or above 124 mph
(200 km/h)
R if you are driving with the DISTRONIC PLUS
Steering Assist activated
R if the time has been set incorrectly
R in active driving situations, such as when
you change lanes or change your speed
ATTENTION ASSIST is reset when you con-
tinue your journey and starts assessing your
tiredness again if:
R you switch off the engine
R you 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 Driving systems
213Driving and parking Z

You can have current status information dis-
played in the assistance menu (Y page 235)
of the on-board computer.
X Select the Assistance display for ATTEN-
TION ASSIST using the on-board computer
(Y page 235).
The following information is displayed:
R length of the journey since the last break.
R the attention level determined by ATTEN-
TION ASSIST, displayed in a bar display in
five levels from high to low.
R if ATTENTION ASSIST is unable to calculate
the attention level and cannot output a
warning, the System Suspended System Suspended message
appears. The bar display then changes the
display, e.g. if you are driving at a speed
below 37 mph (60 km/h) or above 124 mph
(200 km/h).
Activating ATTENTION ASSIST X
Activate ATTENTION ASSIST using the on-
board computer (Y page 236).
The system determines the attention level
of the driver depending on the setting
selected:
Standard selected: the sensitivity with
which the system determines the attention
level is set to normal.
Sensitive selected: the sensitivity is set
higher. The attention level detected by Atten- tion Assist is adapted accordingly and the
driver is warned earlier.
When ATTENTION ASSIST is deactivated, the À symbol and OFF appear in the multi-
function display in the assistance display
when the engine is running.
When ATTENTION ASSIST has been deactiva- ted, it is automatically reactivated after the
engine has been stopped. The sensitivity
selected corresponds to the last selection
activated (standard/sensitive). Warning in the multifunction display If fatigue or increasing lapses in concentra-
tion are detected, a warning appears in the
multifunction display: Attention Assist:
Attention Assist:
Take a Break! Take a Break!
In addition to the message shown in the mul-
tifunction display, you will then hear a warn-
ing tone.
X If necessary, take a break.
X Confirm the message by pressing the a
button on the steering wheel.
On long journeys, take regular breaks in good time to allow yourself to rest properly. If you
do not take a break, you will be warned again
after 15 minutes at the earliest. This will only
happen if ATTENTION ASSIST still detects
typical indicators of fatigue or increasing lap-
ses in concentration.
Vehicles with COMAND: if a warning is
issued in the multifunction display, a service
station search is performed in COMAND. You
can select a service station and navigation to this service station will then begin. This func- tion can be activated and deactivated in
COMAND. Lane Tracking package
General notes The Lane Tracking package consists of Blind
Spot Assist (Y
page 214) and Lane Keeping
Assist (Y page 216).
Blind Spot Assist General notes
Blind Spot Assist uses a radar sensor system
to monitor the areas on both sides of your
vehicle. It supports you from a speed of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your
attention to vehicles detected in the moni-
tored area. If you then switch on the corre-
sponding turn signal to change lanes, you will also receive an optical and audible collision 214
Driving systemsDriving and parking

warning. Blind Spot Assist uses sensors in the
rear bumper for monitoring purposes.
Important safety notes G
WARNING
Blind Spot Assist does not react to:
R vehicles overtaken too closely on the side,
placing them in the blind spot area
R vehicles which approach with a large speed
differential and overtake your vehicle
As a result, Blind Spot Assist may not give
warnings in such situations. There is a risk of an accident.
Always observe the traffic conditions care-
fully, and maintain a safe lateral distance.
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.
i USA 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 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.
Monitoring range of the sensors
In particular, the detection of obstacles can
be impaired if:
R there is dirt on the sensors or anything else
covering the sensors
R there is poor visibility, e.g. due to fog, heavy
rain, snow or spray
R there are narrow vehicles, e.g. motorcycles
or bicycles
R the road has very wide lanes
R the road has narrow lanes R
you are not driving in the middle of the lane
R there 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
driving 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:
R warnings may be issued in error when driv-
ing close to crash barriers or similar solid
lane borders.
R the 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 exam-
ple by cycle racks or overhanging loads. Fol-
lowing a severe impact or in the event of dam- age to the bumpers, have the function of the
sensors checked at a qualified specialist
workshop. Blind Spot Assist may otherwise
not work properly. Driving systems
215Driving and parking Z