2012 MERCEDES-BENZ A CLASS park assist

10 km/h when exiting a parking space.
Otherwise, Active Parking Assist will be
cancelled.
X Stop when PARKTRONIC sounds the con-
tinuous warning tone, if not before.
X Vehicles with manual transmission:
shift to first or reverse gear as required
while the vehicle is stationary.
Vehicles with automatic transmission:
shift
to position D or R as required while the
vehicle is stationary.
Active Parking Assist immediately steers in
the other direction. The Park Assist
active Accelerate and brake
Observe surroundings message appears
in the multifunction display.
i You will achieve the best results by wait-
ing

for the steering procedure to complete
before pulling away.
If you reverse after activation, the steering
wheel is moved to the straight-ahead posi-
tion.
X Drive forwards or reverse the vehicle, being
ready to brake at all times.
X Stop as soon as PARKTRONIC sounds the
continuous warning tone, if not before.
X Drive forwards and reverse as prompted by
the

PARKTRONIC warning displays, several
times if necessary.
Once you have exited the parking space com-
pletely, the steering wheel is moved to the
straight-ahead position. You hear a tone and
the Park Assist switched off message
appears

in the multifunction display. You will
then have to steer and merge into traffic on
your own. PARKTRONIC is still available. Cancelling Active Parking Assist You can cancel Active Parking Assist at any
time.
X
Stop the movement of the multifunction
steering wheel or steer yourself.
Active Parking Assist will be cancelled at
once. The Park Assist cancelled mes-
sage appears in the multifunction display.
or
X Press the PARKTRONIC button on the
centre console

(Y page 185).
PARKTRONIC is switched off and Active
Parking Assist is immediately cancelled.
The Park Assist cancelled message
appears in the multifunction display.
Active Parking Assist is cancelled automati-
cally if:
R you engage the electric parking brake.
R parking using Active Parking Assist is no
longer possible.
R you are driving faster than 10 km/h.
R a

wheel spins and ESP ®
intervenes or fails.
The ÷ warning lamp lights up in the
instrument cluster.
A warning tone sounds. The parking space
symbol disappears and the multifunction dis-
play shows the Park Assist cancelled
message.
When Active Parking Assist is cancelled, you
must steer again yourself.
If a system malfunction occurs, the vehicle is
braked to a standstill. To drive on, depress the
accelerator again.
Towing a trailer For vehicles with a trailer tow hitch, the min-
imum required length for parking spaces is
slightly increased.
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. PARK-
TRONIC is deactivated for the rear area. 190
Driving systems
Driving and parking

function; see the separate COMAND Online
operating instructions.
or
X Select symbol ; for the coupling up a
trailer
function (see the separate COMAND
Online operating instructions).
The symbol of the selected function is high-
lighted.
To deactivate:
the reversing camera is deac-
tivated if you:
R select transmission position P (vehicles
with automatic transmission)
R drive forward ten metres
R for vehicles with an automatic transmis-
sion, shift the transmission from R to
another position after 15 seconds
R shift out of reverse gear (vehicles with man-
ual transmission) after 15 seconds
R drive forwards at a speed of over
10 km/h
Displays in the Audio/COMAND display The reversing camera may show a distorted
view of obstacles, show them incorrectly or
not at all. Obstacles are not shown by the
reversing camera in the following locations:
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. Lanes
:
White guide line without turning the steer-
ing wheel, vehicle width including the
exterior mirrors (static)
; Yellow lane marking the course the tyres
will take at the current steering wheel
angle, vehicle width including the outer
edge of the wheel (dynamic)
= Red guide line for the vehicle width includ-
ing

the exterior mirrors, for current steer-
ing wheel angle (dynamic)
? Bumper Guide lines
?
Bumper
A Red guide line at a distance of approx-
imately

0.25 m from the rear of the vehicle
B Yellow guide line at a distance of approx-
imately

4.0 m from the rear of the vehicle
C Vehicle centre axle (marker assistance)
D Yellow guide line at a distance of approx-
imately

1.0 m from the rear of the vehicle
The lanes and guide lines are only displayed
if you have engaged reverse gear. 192
Driving systems
Driving and parking

:
Vehicle centre point on the yellow guide
line at a distance of approximately
1.0 m
from the rear of the vehicle
; Trailer drawbar
= Ball coupling
X Set the height of trailer drawbar ;
so that
it is slightly higher than ball coupling =.
X Position the vehicle centrally in front of
trailer drawbar ;.:
Ball coupling
; Red guide line at a distance of approx-
imately

0.25 m from the ball coupling
= Trailer drawbar locating aid
? Trailer drawbar
A Symbol for the "Coupling up a trailer"
function
X Select symbol A
with the Audio/COMAND
controller; see the separate operating
instructions for the audio system/
COMAND Online.
The "Coupling up a trailer" function is selec-
ted. The distance specifications now only apply to objects that are at the same level
as the ball coupling.
X Reverse carefully, making sure that trailer
drawbar locating aid = points approx-
imately in the direction of trailer draw-
bar ?.
X Reverse carefully until trailer drawbar ?
touches red guide line ;.
X Couple up the trailer ( Y page 201). ATTENTION ASSIST
General notes ATTENTION ASSIST helps you during long,
monotonous

journeys such as on motorways
and trunk roads. It is active in the 80 km/h
to 180 km/h range.
If ATTENTION ASSIST detects typical indica-
tors of fatigue or increasing lapses in con-
centration on the part of the driver, it sug-
gests taking a break.
Important safety notes ATTENTION ASSIST is only an aid. It cannot
always

detect fatigue or lapses in concentra-
tion until too late or not at all. The system is
not a substitute for a well-rested and atten-
tive driver.
ATTENTION ASSIST assesses your level of
fatigue or lapses in concentration by taking
the following criteria into account:
R your personal driving style, e.g. steering
characteristics
R journey-related parameters, e.g. time of
day, length of journey
The functionality of ATTENTION ASSIST is
restricted, and warnings may be delayed or
not occur at all:
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 Driving systems
195
Driving and parking Z

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 80 km/h or faster than 180 km/h
R if you are currently using COMAND Online
or making a telephone call with COMAND
Online
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 219).
If ATTENTION ASSIST is active, you will be
warned no sooner than 20 minutes after
your journey has begun. You then hear an
intermittent warning tone twice and the
Attention Assist: Take a break!
message appears in the multifunction dis-
play.
X If necessary, take a break.
X Press the a or % button 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, 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.
ATTENTION ASSIST is reset and starts
assessing your tiredness again when you con-
tinue your journey 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
When ATTENTION ASSIST is deactivated, the
é symbol appears in the multifunction
display in the assistance graphic display. Speed Limit Assist
General notes Speed Limit Assist shows you detected speed
limits in the multifunction display. Data from
the navigation system is also used for this
purpose. If a traffic sign indicating a speed
limit or the end of a speed limit is detected,
it is shown in the multifunction display. If
Speed

Limit Assist does not detect any traffic
signs, the speed limit from the digital road
map is taken and shown in the display.
Speed Limit Assist detects the traffic signs
with a camera attached behind the top of the
windscreen. :
Speed Limit Assist camera
Important safety notes Speed Limit Assist is only an aid and does not
always detect traffic signs specifying the
maximum permissible speed. Traffic signs
always have priority over the Speed Limit
Assist display.
The

system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to snow,
rain, fog or spray
R there is glare, e.g. from the sun or from
oncoming traffic
R the windscreen is dirty, misted up or cov-
ered, for instance by a sticker, in the vicinity
of the camera
R the traffic signs are covered, for instance
by dirt, snow or trees196
Driving systems
Driving and parking

R
the traffic signs are poorly illuminated
R there are ambiguous traffic signs, for
instance near roadworks or on multi-lane
roads
Information
in the multifunction displayBriefly showing detected traffic signs in
the multifunction display
X
Activate the Speed Limit Assist warning
function using the on-board computer
(Y page 218).
A

traffic sign indicating a speed limit or the
end of a speed limit appears in the multi-
function display for around five seconds as
soon as it is detected. Any other informa-
tion in the multifunction display is hidden
for this period. :
Maximum permissible speed (example)
; Maximum permissible speed for vehicles
subject

to the restriction in the additional
sign (example)
= Additional character in fog
? Speed Limit Assist is available and
switched on Permanently showing detected traffic
signs in the multifunction display
X
Display the assistance graphic using the
on-board computer (Y page 217).
A

traffic sign indicating a speed limit or the
end of a speed limit appears in the multi-
function display as soon as it is detected.
The traffic sign indicating a speed limit : is
generally displayed until:
R a

traffic sign indicating the end of the speed
limit is detected.
R you make a turn.
R you leave or enter a town.
R the road type changes (e.g. motorway,
country road).
R you have travelled a certain minimum dis-
tance without the traffic sign being repea-
ted or detected again. Lane Tracking package
General notes The Lane Tracking package consists of Blind
Spot Assist

(Y page 198) and Lane Keeping
Assist (Y page 199).
Blind Spot Assist 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 if you overtake these with a difference in
speed in excess of 12 km/h
R or if they approach with a great relative
speed and overtake you
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. Driving systems
197
Driving and parking Z

Blind Spot Assist is only an aid. It may fail to
detect
some vehicles and is no substitute for
attentive driving.
General notes
Blind Spot Assist uses a radar sensor system
to monitor the areas on both sides of your
vehicle. It supports you from speeds of
30 km/h. A warning display in the exterior
mirrors draws your attention to vehicles
detected in the monitored area. If you then
switch on the corresponding turn signal to
change lane, you will also receive an optical
and audible collision warning. For this pur-
pose, Blind Spot Assist uses sensors in the
rear bumper.
The radar sensor system is switched off auto-
matically in the vicinity of radio telescope
facilities ( Y page 350).
For Blind Spot Assist to assist you when driv-
ing, the radar sensor system must be:
R activated(Y page 223)
R operational
i In some countries you must deactivate
the radar sensor system ( Y page 223).
For further information about the radar sen-
sor system; see ( Y page 350).
Monitoring range of the sensors
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or anything else cover-
ing the sensors
R poor visibility, e.g. due to fog, heavy rain or
snow
R a narrow vehicle travelling in front, e.g. a
motorcycle or a bicycle
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

m behind your vehicle and directly next to
your vehicle, as shown in the diagram. For this
purpose, 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 the vehicles are driving on the
inner side of their lane.
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 particularly long vehicles, for
example lorries, for a prolonged time.
The two 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
radar 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
radar sensors checked at a qualified special-
ist workshop. Blind Spot Assist may other-
wise not work properly. 198
Driving systems
Driving and parking

Indicator and warning display
Blind
Spot Assist is not active at speeds below
approximately 30 km/h. Vehicles in the mon-
itoring range are then not indicated. :
Yellow indicator lamp/red warning lamp
If Blind Spot Assist is switched on, indicator
lamp : in the exterior mirrors lights up yel-
low up to a speed of

30 km/h. At speeds
above 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
30 km/h, warning lamp : on the corre-
sponding side lights up in red. This warning
always occurs 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 12 km/h.
The yellow indicator lamp goes out if reverse
gear is engaged. Blind Spot Assist is then
deactivated.
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 : flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :. There are no further warning tones. Activating Blind Spot Assist
X
Make sure that the radar sensor system
(Y page 223) and Blind Spot Assist
(Y page

219) are activated in the on-board
computer.
X Turn the key to position 2 in the ignition
lock.
Warning lamps : in the exterior mirrors
light up red for approximately
1.5 seconds

and then turn yellow.
Towing a trailer
If
you attach a trailer, make sure that you have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamp lights up yel-
low in the exterior mirrors and the Blind
Spot Assist currently unavailable
See Owner'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 if:
R the key is in position 2 in the ignition
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 by means of a camera at
the top of the windscreen. Lane Keeping
Assist detects lane markings on the road and
warns you before you leave your lane unin-
tentionally. Driving systems
199
Driving and parking Z

:
Lane Keeping Assist camera
If you select km on the on-board computer in
the Display unit Speed-/odometer func-
tion (Y page 220), Lane Keeping Assist is
active starting at a speed of 60 km/h
. If the
miles display unit is selected, the assistance
range begins at 40 mph.
Important safety notes G
WARNING
Lane Keeping Assist cannot always clearly
identify lane markings.
In these cases, Lane Keeping Assist may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and keep in lane, especially if Lane
Keeping Assist alerts you. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There
is a risk of an accident.
Always steer, apply the brakes or accelerate
the vehicle yourself, especially if Lane Keep-
ing Assist alerts you.
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 account
road, weather or traffic conditions. Lane
Keeping Assist is only an aid. You are respon-
sible for the distance to the vehicle in front, for vehicle speed, for braking in good time,
and for staying in the lane.
Lane

Keeping Assist does not keep your vehi-
cle in its lane.
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 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
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
steering wheel for up to 1.5 seconds.
Activating Lane Keeping Assist
X Activate Lane Keeping Assist using the on-
board computer; to do so, select Stand‐
ard or Adaptive(Y page 219).
If you drive at speeds above

60 km/h and
lane markings are detected, the lane mark-
ings in the assistance graphics display
(Y page 217) are shown in green. 200
Driving systems
Driving and parking