Lane assist MERCEDES-BENZ S-Class 2011 W221 User Guide

recognize dangers too late which could result
in an accident and serious injury to you and/
or others.
ATTENTION ASSIST assesses your level of
fatigue or lapses in concentration by taking
the following criteria into account:
Ryour personal driving style, e.g. steering
characteristics
Rdriving conditions, e.g. time, driving time
The functionality of ATTENTION ASSIST is
restricted and warnings may be delayed or
not occur at all:
Rif the road condition is poor, e.g. if the
surface is uneven or if there are potholes
Rif there is a strong side wind
Rif you have adopted a sporty driving style
with high cornering speeds or high rates of
acceleration
Rif you are predominantly driving slower
than 50 mph (80 km/h) or faster than
112 mph (180 km/h)
Rif you are currently operating or making a
call using COMAND
Rif the time has been set incorrectly
Rin active driving situations, such as when
you change lanes or change your speed
Warning and display messages in the
multifunction display
XActivate ATTENTION ASSIST using the on-
board computer (Y page 376).
Symbol : appears in the multifunction
display.
If ATTENTION ASSIST is active, it will not warn
you until at least 20 minutes after your
journey has begun. You then hear an
intermittent warning tone twice and the
Attention Assist Time for a break?
message appears in the multifunction
display.
XIf necessary, take a break.XPress a to confirm the message.
On long journeys, take regular breaks in good
time to allow yourself to rest properly. If you
do not take a break and ATTENTION ASSIST
still detects fatigue or increasing lapses in
concentration, you will be warned again after
15 minutes at the earliest.
ATTENTION ASSIST is reset when you
continue your journey, and it starts assessing
your tiredness again 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.
Night View Assist Plus
Important safety notes
In addition to the illumination provided by the
normal headlamps, Night View Assist Plus
uses infrared light to illuminate the road. A
camera at the top of the windshield picks up
the infrared light and displays a black-and-
white image in the multifunction display. The
image shown in the multifunction display
corresponds to a road lit up by high-beam
headlamps. This enables you to see the road's
course and any obstacles in good time. If
pedestrian recognition is activated,
pedestrians recognized by the system are
highlighted in the Night View Assist Plus
display.
GWarning
Night View Assist Plus is only an aid designed
to assist driving. It is not a substitute for
attentive driving. Do not rely solely on the
Night View Assist Plus display. Continue to
look through the windshield. You are
responsible for safety and must drive in
348Driving systemsDriving and parking

Problems with Night View Assist PlusProblemPossible causes/consequences and M SolutionsThe picture quality of
Night View Assist Plus
has deteriorated.The windshield wipers are smearing the windshield.XReplace the wiper blades ( Y page 281).The windshield is smeared after the vehicle has been cleaned in a
car wash.XClean the windshield ( Y page 455).There is windshield chip damage in the camera's field of vision.XReplace the windshield.The windshield is fogged up on the inside.XDefrost the windshield ( Y page 293).The windshield is iced up.XDe-ice the windshield ( Y page 292).There is dirt on the inside of the windshield.XClean the inside of the windshield ( Y page 455).Driving Assistance package
General information
i The Driving Assistance package is only
available on vehicles with HYBRID.
The Driving Assistance package consists of
DISTRONIC PLUS ( Y page 325), Blind Spot
Assist ( Y page 352) and Lane Keeping Assist
( Y page 354).
Blind Spot Assist
Important safety guidelines
Blind Spot Assist uses a radar sensor system
to monitor the areas on both sides of your
vehicle. Blind Spot Assist provides assistance
at speeds higher than 20 mph (30 km/h). A
warning display in the exterior mirrors draws
your attention to vehicles in the monitored
area. If you then indicate a turn towards that
side before changing lanes, you will also
receive visual and audible collision warnings.
For this purpose, Blind Spot Assist uses
sensors in the rear bumper.GWarning
Blind Spot Assist is only an aid designed to
assist driving. It may fail to detect some
vehicles and is no substitute for attentive
driving.
Blind Spot Assist cannot detect road and
traffic conditions. It may fail to detect narrow
vehicles, such as motorcycles or bicycles, or
may only detect them too late.
Monitoring may be affected by dirty sensors,
strong spray or poor visibility caused by snow,
rain or mist, for example. In this case, vehicles
are detected late or not at all.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
i USA only:
352Driving systemsDriving and parking

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.
For Blind Spot Assist to assist you when
driving, the radar sensor system must be
activated (Y page 378) and operational.
Monitoring range of the sensors
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.
GWarning
Blind Spot Assist monitors certain areas in the
immediate vicinity of your vehicle. Vehicles
that approach and drive past at high speeds
are not detected. There is no display and no
warning.
If the lanes are very wide, it may not be
possible to monitor the complete width of the
neighboring lane. For this reason, vehicles in
the next lane may not be detected, especially
if they are driving in a staggered formation.
This may be the case if vehicles are driving at
that edge of their lane which is furthest away
from your vehicle.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
If the lanes are narrow, the system may be
unable to distinguish the neighboring lane
from the one beyond it. For this reason,
vehicles in the farther lane may be indicated,
especially if the vehicles are driving in a
staggered formation in different lanes. In
particular, this may be the case if the vehicles
are driving at the edge of their lane nearest
your vehicle. Due to the nature of the system,
warnings may be issued in error when driving
close to crash barriers or similar solid lane
borders.
The two sensors for Blind Spot Assist are
integrated into the sides of the rear bumper.
Make sure that the bumper is free from dirt,
ice, or slush around the sensors. For example,
the radar sensors must not be covered 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 specialist
workshop, e.g. an authorized Mercedes-Benz
Center. Blind Spot Assist may otherwise not
work properly.
Information and warning display
:Yellow indicator lamp/red warning lampDriving systems353Driving and parkingZ

When Blind Spot Assist is activated, indicator
lamp : in the exterior mirrors lights up in
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 Blind Spot Assist
is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
20 mph (30 km/h), warning lamp : on the
corresponding side lights up in 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.
GWarning
Blind Spot Assist is not active at speeds under
approximately 20 mph (30 km/h). The
indicator lamps in the exterior mirrors are
yellow. Vehicles in the monitoring range are
then not indicated.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the turn
signal, a double warning tone sounds. Red
warning lamp : flashes. If the turn signal
remains on, detected vehicles are indicated
by the flashing of red warning lamp :. There
are no further warning tones.
Switching on Blind Spot Assist
XMake sure that the radar sensor system
(Y page 378) and Blind Spot Assist
(Y page 376) are activated in the on-board
computer.
XTurn the SmartKey to position 2 in the
ignition lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.
Lane Keeping Assist
Important safety notes
Lane Keeping Assist monitors the area in
front of your vehicle by means of a camera at
the top of the windshield. Lane Keeping Assist
detects lane markings on the road and warns
you before you leave your lane
unintentionally.
:Lane Keeping Assist camera
If you select km/h on the on-board computer
in the Display Unit Speed-/Odometer:
function (Y page 377), Lane Keeping Assist
is activated from speeds of 60 km/h. If the
mph display unit is selected, the assistance
range begins at 40 mph.
GWarning
Lane Keeping Assist does not keep your
vehicle in its lane. It is only an aid and may
detect the lane markings on the road
incorrectly or not at all.
354Driving systemsDriving and parking

The system may be impaired or may not
function if:
Rthere is poor visibility, e.g. due to
insufficient illumination of the road, or due
to snow, rain, fog or spray.
Rthere is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles.
Rthe windshield is dirty, fogged up or
covered, for instance by a sticker, in the
vicinity of the camera.
Rseveral or no lane markings for a single lane
are present.
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 on the road are unclear,
e.g. near roadworks.
Rthe lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
Rthe road is narrow and winding.
Lane Keeping Assist cannot detect road and
traffic conditions. It is not a substitute for
attentive driving. You are responsible for the
vehicle's speed, braking in good time, and
steering correctly. Always adapt your driving
style to suit the prevailing road and weather
conditions. Always pay attention to traffic
conditions and your surroundings. Otherwise,
you may fail to recognize dangers in time,
cause an accident and injure yourself and
others.
A warning can be given when a front wheel
passes over a lane marking. It will warn you
by means of intermittent vibration in the
steering wheel for up to 1.5 seconds.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a
freeway.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
No warning vibration occurs if:
Ryou clearly and actively steer, brake, or
accelerate.
Ryou cut the corner on a sharp bend.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Activating Lane Keeping Assist
XActivate Lane Keeping Assist using the on-
board computer (Y page 376).
Symbol : appears in the multifunction
display.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
symbol : is displayed in green. Lane
Keeping Assist is ready for use.
Active Driving Assistance package
General information
iThe Active Driving Assistance package is
only available on vehicles without HYBRID.
The Active Driving Assistance package
consists of DISTRONIC PLUS (Y page 325),
Driving systems355Driving and parkingZ

Active Blind Spot Assist (Y page 356) and
Active Lane Keeping Assist ( Y page 359).
Active Blind Spot Assist
Important safety notes
Active Blind Spot Assist uses a radar sensor
system to monitor the side areas of your
vehicle. In addition, it uses the radar sensor
system to monitor the front area as well.
Active Blind Spot Assist is active at speeds
above approximately 20 mph (30 km/h). A
warning lamp in the exterior mirrors calls your
attention to a vehicle or certain obstacles in
the area monitored. If you switch on the
corresponding turn signal before changing
lane, you will also receive visual and audible
collision warnings. If a risk of lateral collision
is detected, corrective braking may help you
avoid a collision.
GWarning
Active Blind Spot Assist is only an aid, and
may detect vehicles/obstacles incorrectly or
not at all.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to snow,
rain, fog or spray.
R the rear and/or front sensors are dirty.
Active Blind Spot Assist may not detect
narrow vehicles, such as motorcycles or
bicycles, or only detect them too late. It
cannot detect vehicles that are overtaken at
a small distance and then enter the blind spot
area.
Active Blind Spot Assist cannot detect road
and traffic conditions. It is not a substitute for
attentive driving. You are responsible for the
vehicle's speed, braking in good time, and
steering correctly. Always adapt your driving
style to suit the prevailing road and weather
conditions. Always pay attention to traffic
conditions and your surroundings. Otherwise,
you may fail to recognize dangers in time,
cause an accident and injure yourself and
others.
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. 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.
For Active Blind Spot Assist to assist you
when driving, the radar sensor system must
be activated ( Y page 378) and operational.
Monitoring range
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 sensors in the rear bumper.GWarning
Active Blind Spot Assist monitors certain
areas in the immediate vicinity of your vehicle.
Vehicles that approach and drive past at high
speeds are not detected. No visual nor
audible warnings are emitted and the system
does not brake the vehicle to correct your
course.
356Driving systemsDriving and parking

If the lanes are very wide, it may not be
possible to monitor the complete width of the
neighboring lane. For this reason, vehicles in
the next lane may not be detected, especially
if they are driving in a staggered formation.
This may be the case if vehicles are driving at
the edge of their lane that is furthest away
from your vehicle.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
If the lanes are narrow, the system may be
unable to distinguish the neighboring lane
from the one beyond it. For this reason,
vehicles in the farther lane may be indicated,
especially if the vehicles are driving in a
staggered formation in different lanes. In
particular, this may be the case if the vehicles
are driving at the edge of their lane nearest
your vehicle. Due to the nature of the system,
warnings may be issued in error when driving
close to crash barriers or similar solid lane
borders.
Two Active Blind Spot Assist sensors are
integrated into the front and rear bumpers
respectively. An additional sensor is located
behind the cover in the radiator grill. Make
sure that the bumpers are free from dirt, ice
or slush around the sensors. The rear radar
sensors must not be covered, for example 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, e.g. an authorized Mercedes-Benz
Center. Active Blind Spot Assist may
otherwise fail to work correctly.
Information and warning display:Yellow indicator lamp/red warning lamp
When Active Blind Spot Assist is activated,
indicator lamp : in the exterior mirrors lights
up in 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 monitoring
range of Blind Spot Assist at speeds above
(30 km/h), warning lamp : on the
corresponding side lights up in 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. Active Blind Spot Assist is
then no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
GWarning
Active Blind Spot Assist is not active at speeds
lower than 20 mph (30 km/h). The indicator
lamps in the exterior mirrors are yellow.
Vehicles in the monitoring range are then not
indicated.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Driving systems357Driving and parkingZ

Optical and acoustic collision warning
When you switch on the appropriate turn
signals to change lanes, and a vehicle is
detected in the side monitoring range of
Active Blind Spot Assist, you receive an
optical and acoustic collision warning. You
then hear a double warning tone, and red
warning lamp : flashes. If the turn signal
remains on, detected vehicles are indicated
by the flashing of red warning lamp :. There
are no further warning tones.
Course-correcting brake application
If Active Blind Spot Assist detects a risk of
lateral collision in the monitoring range,
under certain circumstances, it will brake the
vehicle briefly on one side. This is designed to
help you avoid a collision.
This function is available in the range between
20 mph and 120 mph (30 km/h and
200 km/h).
When a course-correcting brake application
occurs, red warning lamp : flashes in the
exterior mirror and the following message, for
example, appears in the multifunction
display:
GWarning
Active Blind Spot Assist is only an aid
designed to assist driving. It is not a substitute
for attentive driving. In some cases, the
course-correcting brake application is not
sufficient to avoid a collision. In such a case,
you must steer, brake or accelerate.
In very rare cases, the system may
erroneously detect a danger of collision in the
area of crash barriers or similar lane borders
and apply the brakes. Active Blind Spot Assist
does not detect all traffic situations and road
users. Always make sure that there is
sufficient distance to the side for other traffic
or obstacles. An inappropriate brake
application may be interrupted at any time if
you steer slightly in the opposite direction or
accelerate.
You are responsible for the vehicle's speed,
braking in good time, and steering correctly.
Always adapt your driving style to suit the
prevailing road and weather conditions.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Either a very slight course-correcting brake
application, or none at all, may occur if:
Rother vehicles and/or objects, such as
crash barriers, are detected in the
immediate vicinity of your vehicle.
Ra vehicle approaches you too closely at the
side.
Ryou have adopted a sporty driving style with
high cornering speeds.
Ryou brake or accelerate decisively.
Ra driving safety system intervenes, such as
ESP® or PRE-SAFE® Brake.
RESP® is deactivated.
Ra loss of tire pressure or a defective tire has
been detected and displayed.
Activating Active Blind Spot Assist
XMake sure that the radar sensor system
(Y page 378) and Active Blind Spot Assist
(Y page 376) are activated in the on-board
computer.
XTurn the key to position 2 in the ignition
lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.
358Driving systemsDriving and parking

Active Lane Keeping Assist
Important safety notes
Active Lane Keeping Assist monitors the area
in front of your vehicle by means of a camera
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.
:Active Lane Keeping Assist camera
If you select km on the on-board computer in
the Display Unit Speed-/
Odometer (Y page 377) function, Active Lane
Keeping Assist is activated starting at a speed
of 60 km/h. If the mph display unit is selected,
the assistance range begins at 40 mph.
GWarning
Active Lane Keeping Assist does not keep
your vehicle in its lane. It is only an aid and
may detect the lane markings on the road
incorrectly or not at all.
The system may be impaired or may not
function if:
Rseveral or no lane markings for a single lane
are present.
Rthere is poor visibility, e.g. due to
insufficient illumination of the road, or due
to snow, rain, fog or spray.
Rthere is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles.
Rthe windshield is dirty, fogged up or
covered, for instance by a sticker, in the
vicinity of the camera.
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 on the road are unclear,
e.g. near roadworks.
Rthe lane markings change quickly, e.g.
lanes branch off, cross one another or
merge.
Rthe road is narrow and winding.
Active Lane Keeping Assist cannot detect
road and traffic conditions. It is not a
substitute for attentive driving. You are
responsible for the vehicle's speed, braking in
good time, and steering correctly. Always
adapt your driving style to suit the prevailing
road and weather conditions. Always pay
attention to traffic conditions and your
surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
Warning vibration in the steering wheel
A warning can be given when a front wheel
passes over a lane marking. It will warn you
by means of intermittent vibration in the
steering wheel for up to 1.5 seconds.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a
freeway.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Driving systems359Driving and parkingZ

No warning vibration occurs if:
Ryou clearly and actively steer, brake, or
accelerate.
Ryou cut the corner on a sharp bend.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Lane-correcting brake application
If you leave your lane under certain
circumstances, the vehicle will brake briefly
on one side. This is designed to help you bring
the vehicle back into the original lane.
This function is available in the range between
40 mph and 120 mph (60 km/h and
200 km/h).
A lane-correcting brake application can only
be made after driving over a solid,
recognizable lane marking. You will be
warned beforehand by means of an
intermittent vibration in the steering wheel.
In addition, a lane with lane markings on both
sides must be recognized. The brake
application also slightly reduces driving
speed.
If a lane-correcting brake application occurs,
the following message appears in the
multifunction display:
iA further lane-correcting brake
application can only occur after your
vehicle has returned to the original lane.
GWarning
Active Lane Keeping Assist does not keep
your vehicle in its lane. It is only an aid
designed to assist driving. It is not a substitute
for attentive driving. In some cases, the lane-
correcting brake application is not sufficient
to bring your vehicle back to the original lane.
In such cases, you must steer the vehicle
yourself to ensure that it does not leave the
lane.
Active Lane Keeping Assist does not detect
road and traffic conditions. Always make sure
that there is sufficient distance to the side for
other traffic or obstacles. In rare cases,
unclear markings or particular structures on
the roadway can be recognized as solid lane
markings. An inappropriate brake application,
e.g. after intentionally driving over a solid lane
marking, may be interrupted at any time by
steering slightly in the opposite direction.
Active Lane Keeping Assist cannot take
account of weather conditions.
You are responsible for the vehicle's speed,
braking in good time, and steering correctly.
Always adapt your driving style to suit the
prevailing road and weather conditions.
Always pay attention to traffic conditions and
your surroundings. Otherwise, you may fail to
recognize dangers in time, cause an accident
and injure yourself and others.
No lane-correcting brake application occurs
if:
Ryou clearly and actively steer, brake, or
accelerate.
Ryou cut the corner on a sharp bend.
Ryou switch on the turn signals.
Ra driving safety system intervenes, such as
ESP®, PRE-SAFE® Brake or Active Blind
Spot Assist.
Ryou have adopted a sporty driving style with
high cornering speeds or high rates of
acceleration.
RESP® is deactivated.
Rthe transmission is not in position D.
Ra loss of tire pressure or a defective tire has
been detected and displayed.
360Driving systemsDriving and parking