2012 MERCEDES-BENZ A CLASS display

The distance specifications only apply to
objects that are at ground level.
Additional displays on vehicles with PARKTRONIC
and COMAND Online
:
Front warning display
; Additional PARKTRONIC operational read-
iness indicator
= Rear warning display
Vehicles with PARKTRONIC and COMAND
Online: when PARKTRONIC is operational
(Y page 182), additional operational readi-
ness indicator ; appears in the COMAND
display.If the PARKTRONIC warning displays
are
active or light up, warning displays : and
= are also active or light up correspondingly
in the COMAND display.
Reverse parking function X
Make sure that the reversing camera is
activated and the "Reverse parking" func-
tion

is selected; see the separate operating
instructions for the audio system/
COMAND Online.
The lane and the guide lines are shown. Reversing straight into a parking space
without turning the steering wheel :
White lane indicating the route the vehicle
will take with the steering wheel straight
; Yellow guide line at a distance of approx-
imately

1.0 m from the rear of the vehicle
= Red guide line at a distance of approx-
imately

0.25 m from the rear of the vehicle
X With the help of white lane :, check
whether
the vehicle will fit into the parking
space.
X Using the white lane as a guide, carefully
reverse until you reach the end position.
Red guide line = is then at the end of the
parking

space. The vehicle is almost paral-
lel in the parking space.
Reverse perpendicular parking with the
steering wheel at an angle
X Drive past the parking space and bring the
vehicle to a standstill. Driving systems
193
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

X
To open the cover: turn handle : anti-
clockwise and fold down cover ; and
remove it. X
Pull out release wheel =.
X Turn release wheel = anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator
lamp ? flashes. G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is a risk of an
accident.
Always

engage the ball coupling as described.
X Pull the ball coupling in the direction of the
arrow

until it engages in a vertical position.
Indicator lamp ? goes out. The power
socket folds down automatically.
The multifunction display shows the
Check trailer hitch lock display mes-
sage until the ball coupling is engaged.
X Remove the protective covering from the
ball coupling and store it in a safe place.
X Make sure that the ball of the ball coupling
is clean and that it is either greased or dry
(grease free), depending on the instruc-
tions for the trailer. Coupling up a trailer
X Make sure that the transmission is in posi-
tion P.
X Apply the electric parking brake.
X Position the trailer level behind the vehicle.
X Couple up the trailer.
X Establish the electric connection between
the vehicle and the trailer.
X Check that the trailer lighting system is
working.
A trailer that is connected is recognised
only when the electrical connection is
established

correctly and when the lighting
system is working properly. The function of
other systems, such as ESP ®
or PARK-
TRONIC also depends on this. Uncoupling a trailer
G
WARNING
If you uncouple a trailer with an engaged over-
run
brake, you could trap your hand between204
Towing a trailer
Driving and parking

X
Press the ball coupling in the direction of
the arrow until it engages behind the
bumper.
Indicator lamp ? goes out and the mes-
sage in the multifunction display disap-
pears. Trailer power supply
! You can connect accessories with a
power rating of up to 240 W to the perma-
nent
power supply and with a power rating
of up to 180 W to the power supply that is
switched on via the ignition lock.
The trailer battery may not be charged from
the power supply.
X To switch the connected power supply
on or off: turn the key in the ignition lock
to position 2 or 0 respectively.
When it leaves the factory, your vehicle's
trailer socket is equipped with a permanent
power supply and a power supply that is
switched on via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin
10.
The trailer's permanent power supply is
switched

off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about instal-
ling the trailer electrics at a qualified special-
ist workshop. Bulb failure indicator for LED lamps
i If LED lamps are fitted in the trailer, an
error message may appear in the multi-
function

display even if there is no fault. The
reason for the error message could be that
the current has fallen below the minimum
of 50 mA. To ensure reliable operation of the bulb failure
indicator,

each LED chain in the trailer lighting
must be guaranteed a minimum current of
50 mA. Trailer with 7-pin connector
General notes Trailer with 7-pin connector: you can con-
nect

to the 13-pin socket on the ball coupling
using an adapter or, if necessary, an adapter
cable. Both can be obtained at a qualified
specialist workshop.
Fitting the adapter !
Make sure that there is sufficient cable
play so that the cable cannot become
detached when cornering.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable. X
Open the socket cover.
X Insert the plug connector with lug : into
groove =

on the socket. Turn bayonet con-
nection ; clockwise to the stop.
X Let the cover engage.
X If you are using an adapter cable, secure
the cable to the trailer with cable ties.206
Towing a trailer
Driving and parking