R
if you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
R if you are predominantly driving slower
than 50 mph (80 km/h) or faster than
112 mph (180 km/h)
R if you are currently using COMAND or mak-
ing a telephone call with it
R if the time has been set incorrectly
R in active driving situations, such as when
you change lanes or change your speed
Warning and display messages in the
multifunction display X
Activate ATTENTION ASSIST using the on-
board computer (Y page 229).
If ATTENTION ASSIST is active, you will be
warned no sooner than 20 minutes after your journey has begun. You then hear an inter-
mittent warning tone twice and the Atten‐
Atten‐
tion
tion Assist: Assist: Drowsiness
Drowsiness detected
detectedmes-
sage appears in the multifunction display.
X If necessary, take a break.
X Press the 0076button to confirm the mes-
sage.
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. The precon-
dition for this is that ATTENTION ASSIST still
detects typical indicators of fatigue or
increasing lapses in concentration.
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.
The assistance graphic shows the 00D7sym-
bol when ATTENTION ASSIST is deactivated
(Y page 229). Lane Tracking package
General notes The Lane Tracking package consists of Blind
Spot Assist (Y page 203) and Lane Keeping
Assist (Y page 205).
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 a visual and audible collision
warning. Blind Spot Assist uses sensors in the rear bumper for monitoring purposes.
For Blind Spot Assist to assist you, the radar
sensor system must be operational.
Important safety notes
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. 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.
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 Driving systems
203Driving and parking Z
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 dirt on the sensors or anything else cover-
ing the sensors
R poor visibility, e.g. due to fog, heavy rain,
snow or spray
R narrow vehicles, e.g. motorcycles or bicy-
cles
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. Blind Spot Assist monitors the area up to 10 ft
(3 m) behind 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 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.
Indicator and warning display
Blind Spot Assist is not active at speeds below approximately 20 mph (30 km/h). Vehicles in the monitoring range are then not indicated. 0043
Yellow indicator lamp/red warning lamp
When Blind Spot Assist is activated, indicator
lamp 0043in the exterior mirrors lights up yel-
low at speeds of up to 20 mph (30 km/h). At speeds above 20 mph (30 km/h), the indica-
tor lamp goes out and Blind Spot Assist is
operational. 204
Driving systemsDriving and parking
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp 0043on 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).
The yellow indicator lamp goes out if reverse gear is engaged. In this event, Blind Spot
Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp 0043flashes. If
the turn signal remains on, vehicles detected
are indicated by the flashing of red warning
lamp 0043. There are no further warning tones.
Switching on Blind Spot Assist
X Make sure that Blind Spot Assist
(Y page 229) is activated in the on-board
computer.
X Turn the SmartKey to position 2in the igni-
tion lock.
Warning lamps 0043in the exterior mirrors
light up red for approximately 1.5 seconds
and then turn yellow.
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. In this event, Blind Spot
Assist is deactivated. The indicator lamp
lights up yellow in the exterior mirrors and the
Blind
Blind Spot SpotAssist
Assist Currently
Currently Unavail‐
Unavail‐
able See Operator's Manual
able See Operator's Manual message
appears in the multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors. To do so, switch off Blind Spot Assist when:
R the SmartKey is in position 2in the igni-
tion lock
R the engine is not running
R the electrical connection to the trailer
has been established
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front of your vehicle with camera
0043, which is
mounted at the top of the windshield. Lane
Keeping Assist detects lane markings on the
road and warns you before you leave your
lane unintentionally. 0043
Active Lane Keeping Assist camera
If you select km kmon the on-board computer in
the Display Unit Speed-/Odometer
Display Unit Speed-/Odometer func-
tion (Y page 230), Lane Keeping Assist is
active starting at a speed of 60 km/h. If the
miles miles display unit is selected, the assistance
range begins at 40 mph.
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.
Important safety notes
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an accident nor override the laws of physics. Lane Keeping Assist cannot take into accountthe road, traffic and weather conditions. Lane
Keeping Assist is merely an aid. You are Driving systems
205Driving and parking Z
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 high-
way.
R the system recognizes solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend.
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Active Driving Assistance package
General notes The Active Driving Assistance package con-
sists of DISTRONIC PLUS (Y page 176), Active
Blind Spot Assist (Y page 207) and Active
Lane Keeping Assist (Y page 210).
Active Blind Spot Assist General notes
Active Blind Spot Assist uses a radar sensor
system to monitor the side areas of your vehi-
cle which are behind the driver. 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 lane, you will
also receive an optical and audible warning. If
a risk of lateral collision is detected, correc-
tive braking may help you avoid a collision. To support the course-correcting brake applica-
tion, Active Blind Spot Assist uses the
forward-facing radar sensor system. The free space is then evaluated in the direction of
travel and to the side before a course-cor-
recting brake application is initiated.
Active Blind Spot Assist supports you from a
speed of approximately 20 mph (30 km/h). For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be operational.
Important safety notes
Active Blind Spot Assist is only an aid. It does
not detect all traffic situations and road users
and is no substitute for attentive driving.
Always ensure that there is sufficient dis-
tance to the side for other road users and
obstacles. G
WARNING
Active 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, 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.
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 automotiveradar 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.
i Canada 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 Driving systems
207Driving and parking Z
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.
Monitoring range of the sensors 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 on the side for other traffic or obstacles.
In particular, the detection of obstacles can
be impaired if:
R dirt on the sensors or anything else cover-
ing the 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. Active Blind Spot Assist monitors the area up
to 10 ft (3 m) behind your vehicle and directly next to your vehicle, as shown in the diagram.
For this purpose, Active Blind Spot Assist
uses radar sensors in the rear bumper. 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.
Two Active Blind Spot Assist radar sensors
are integrated into the front and rear bumpers respectively. An additional radar sensor is
located behind the cover in the radiator grill.
Make sure that the sensors and areas around
them 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 sensors checked at a qualified specialist workshop.
Blind Spot Assist may otherwise not work
properly.
Indicator and warning display
Active Blind Spot Assist is not active at
speeds below approximately 20 mph
(30 km/h). Vehicles in the monitoring range
are then not indicated. 0043
Yellow indicator lamp/red warning lamp
When Active Blind Spot Assist is activated,
indicator lamp 0043in the exterior mirrors lights 208
Driving systemsDriving and parking
up yellow at speeds of up to 20 mph
(30 km/h). At speeds above 20 mph
(30 km/h), the indicator lamp goes out and
Active Blind Spot Assist is operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp 0043on 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).
The yellow indicator lamp goes out if reverse gear is engaged. In this event, Active Blind
Spot Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Visual and acoustic collision warning
When 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 then hear a double warning tone and red warning
lamp 0043flashes. If the turn signal remains on,
detected vehicles are indicated by the flash-
ing of red warning lamp 0043. There are no fur-
ther warning tones.
Course-correcting brake application G
WARNING
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.
In very rare cases, the system may make an
inappropriate brake application. An inappro-
priate brake application may be interrupted at any time if you steer slightly in the opposite
direction or accelerate. 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.
The course-correcting brake application is
available in the speed range between 20 mph (30 km/h) and 120 mph (200 km/h).
If a course-correcting brake application
occurs, red warning lamp 0043flashes in the
exterior mirror and the following is shown in
the multifunction display, for example: Either a very slight course-correcting brake
application, or none at all, may occur if:
R there are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehi-
cle.
R a vehicle approaches you too closely at 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, e.g.
ESP ®
or PRE-SAFE ®
Brake.
R ESP ®
is switched off.
R a loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist X Make sure that Active Blind Spot Assist
(Y page 229) is activated in the on-board
computer.
X Turn the SmartKey to position 2in the igni-
tion lock.
Warning lamps 0043in the exterior mirrors
light up red for approximately 1.5 seconds
and then turn yellow. Driving systems
209Driving and parking Z
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Active Blind Spot Assist is then deactivated. The indicator lamp lights up
yellow in the exterior mirrors and the Active
Active
Blind
Blind Spot SpotAssist
Assist Currently
Currently Unavail‐
Unavail‐
able See Operator's Manual
able See Operator'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 camera 0043
mounted at the top of the windshield. Active
Lane Keeping Assist detects lane markings on
the road and warns you before you leave your
lane unintentionally. If you do not react to the warning, a lane-correcting application of the
brakes can bring the vehicle back into the
original lane. 0043
Active Lane Keeping Assist camera
If you select km kmon the on-board computer in
the Display Unit Speed-/Odometer
Display Unit Speed-/Odometer func-
tion (Y page 230), Active Lane Keeping Assist
is activated starting at a speed of 60 km/h. If
the miles
miles display unit is selected, the assis-
tance range begins at 40 mph.
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. Lane Keeping Assist cannot take into account the road, traffic and weather condi-
tions. Lane Keeping Assist is merely 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. 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 not give a warning or 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 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 there are no, several or unclear lane mark-
ings for a lane, e.g. in areas with road con- struction work
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 210
Driving systemsDriving an
d parking
G
WARNING
If the ball coupling is not correctly installed
and secured, it could come loose while driving and endanger other road users. There is a risk
of an accident and injury.
Install and secure the ball coupling as descri-
bed in the ball coupling manufacturer's instal- lation instructions. Make sure that the ball
coupling is correctly installed and secured
before every journey. Coupling up a trailer
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadian provinces
require by law: R safety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must be fastened to the vehicle's trailer cou-
pling, not to the bumper or the axle.
Leave enough play in the chains to make
tight cornering possible.
R a separate brake system for certain types
of trailer.
R a safety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing vehi-
cle, the safety switch applies the trailer's
brakes.
! Do not connect the trailer's brake system
(if featured) to the hydraulic brake system
of the towing vehicle, as the latter is equip-
ped with an anti-lock brake system. Doing
so will result in a loss of function of the
brake systems of both the vehicle and the
trailer.
i The vehicle's wiring harness features a
connection to the brake indicator lamp. X
Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's parking brake.
X Close all doors and the tailgate.
X Couple up the trailer.
X Establish all electrical connections. Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions:
R in your place of residence
R in the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer:
R To gain driving experience and to become
accustomed to the new handling charac-
teristics, you should practice the following
in a traffic-free location:
- cornering
- stopping
- backing up
R Before driving, check:
- the trailer tow hitch
- the safety switch for braked trailers
- the safety chains
- electrical connections
- the lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check
whether the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion. Towing a trailer
215Driving and parking Z