lane assist MERCEDES-BENZ A-CLASS HATCHBACK 2012 Owners Manual

ESP® (Electronic Stability Pro-
gram) ......................................... 65, 66
ETS/4ETS (Electronic Traction
System) ........................................... 65
Important safety guidelines ............ .61
Overview .......................................... 61
STEER CONTROL ............................. 69
Driving systems
Active Parking Assist ..................... 186
ATTENTION ASSIST ........................ 195
Blind Spot Assist ............................1 97
Cruise control ................................ 168
Display message ............................ 245
Distronic Plus ................................ 173
HOLD function ............................... 179
Lane Keeping Assist ..................... .199
Lane package ................................ 197
PARKTRONIC ................................. 182
RACE START (AMG vehicles) .......... 181
Reversing camera .......................... 191
Speed Limit Assist ......................... 196
SPEEDTRONIC ............................... 171
Driving tips
Aquaplaning ................................... 167
Automatic transmission ................. 154
Brakes .......................................... .166
DISTRONIC PLUS ........................... 178
Downhill gradient ........................... 166
Driving abroad ............................... 104
Driving in winter ............................ .167
Driving on flooded roads ................ 167
Driving on wet roads ..................... .167
General .......................................... 165
Icy road surfaces ........................... 168
Limited braking efficiency on sal-
ted roads ....................................... 167
New brake pads/linings ................ 167
Running-in tips ............................... 142
Snow chains .................................. 321
Symmetrical dipped bea m............. 104
Towing a trailer .............................. 201
Wet road surface ........................... 166
DVD audio (on-board computer) ...... 215 E
EASY-VARIO-PLUS system Luggage compartment enlarge-
ment .............................................. 271
EBD (electronic brake force distri-
bution)
Display message ............................ 232
Function/note s................................ 68
ECO display
Function/note s............................. 165
On-board computer ....................... 212
ECO start/stop function
Automatic engine start .................. 147
Automatic engine switch-off .......... 146
Deactivating/activating ................. 147
General information ....................... 146
Important safety notes .................. 146
Introduction ................................... 145
Electrical fuses
see Fuses
Electronic Stability Program
see ESP® (Electronic Stability Program)
Emergency key
Unlocking the driver's door .............. 81
Emergency key element
Function/note s................................ 75
Locking vehicle ................................ 81
Emergency release
Driver's door .................................... 81
Emergency spare wheel
General notes ................................ 332
Important safety notes .................. 332
Removing ....................................... 332
Technical data ............................... 333
Emergency unlocking
Tailgate ............................................ 83
Vehicle ............................................. 81
Engine
Display message ............................ 243
ECO start/stop function ................ 145
Engine number ............................... 338
Jump-starting ................................. 308
Running irregularly ......................... 149
Starting problems .......................... 149
Starting the engine with the key .... 144
Stopping ........................................ 162
Tow-starting (vehicle) ..................... 314 Index
9

Overview ........................................1
11
Reading lamp ................................. 111
Setting the ambient lighting
brightness (on-board computer) .... 222
Interior motion sensor ........................ 70
ISOFIX child seat securing system .... 53J
Jack Storage location ............................ 299
Using ............................................. 326
Jump starting (engine) ......................308 K
Key Changing the battery ....................... 76
Checking the battery ....................... 76
Convenience closing feature ............ 85
Convenience opening feature .......... 84
Display message ............................ 256
Door central locking/unlocking ....... 75
Emergency key element ................... 75
Important safety notes .................... 74
Loss ................................................. 78
Modifying the programming ............. 75
Positions (ignition lock) ................. 143
Problem (malfunction) ..................... 78
Starting the engine ........................ 144
Key positions (ignition lock) ............ 143
Kickdown
Driving tips ................................... .154
Manual drive program .................... 158
Kneebag ............................................... 44 L
Lamps see Warning and indicator lamps
Lane Keeping Assist
Activating/deactivating ................. 219
Display message ............................ 247
Function/informatio n.................... 199
Lane package ..................................... 197
Lap time (RACETIMER) ...................... 226
Lashing eyelets ................................. 273
Licence plate lamp (display mes-
sage) ................................................... 241 Light sensor (display message)
....... 242
Lighting
see Lights
Lights
Activating/deactivating the Intel-
ligent Light System ........................ 221
Activating/deactivating the inte-
rior lighting delayed switch-off ....... 223
Active light function ....................... 108
Automatic headlamp mod e............ 105
Cornering light function ................. 109
Dipped-beam headlamp s............... 105
Display message ............................ 239
Driving abroad ............................... 104
Foglamps ....................................... 106
Foglamps (extended range) ........... 109
Hazard warning lamps ................... 108
Headlamp flashe r........................... 108
Headlamp rang e............................ 107
Light switch ................................... 105
Main-beam headlamp s................... 107
Motorway mod e............................. 109
Parking lamps ................................ 106
Rear foglamp ................................. 106
Setting the ambient lighting
brightness (on-board computer) .... 222
Side lamps ..................................... 106
Switching Adaptive Highbeam
Assist on/of f................................. 222
Switching the daytime driving
lights on/off (on-board com-
puter) ............................................. 221
Switching the daytime driving
lights on/off (switch) ..................... 105
Switching the exterior lighting
delayed switch-off on/off (on-
board computer) ............................ 222
Switching the surround lighting
on/off (on-board computer) .......... 222
Turn signals ................................... 107
see Interior lighting
see Replacing bulbs
LIM indicator lamp
Cruise control ................................ 169
DISTRONIC PLUS ........................... 174
Variable SPEEDTRONIC ................. 171
Limiting the speed
see SPEEDTRONIC 12
Index

This speed can:
R be too high for a filter lane or a slip road
R be so high in the right lane that you pass
vehicles driving on the left
R be so high in the left lane that you pass
vehicles driving on the right
If there is a change of drivers, advise the new driver of the speed stored.
General notes DISTRONIC PLUS regulates the speed and
automatically helps you maintain the dis-
tance to the vehicle detected in front. DIS-
TRONIC PLUS brakes automatically so that
the set speed is not exceeded.
You must select a lower gear in good time on long and steep downhill gradients, especially if the vehicle is laden or towing a trailer. For
this, you need to have selected manual drive
program M(Ypage 166). By doing so, you will
make use of the braking effect of the engine.
This relieves the load on the brake system and prevents the brakes from overheating and
wearing too quickly.
If a slower-moving vehicle is detected in front,
DISTRONIC PLUS brakes your vehicle. It
maintains the preset distance to the vehicle in front.
If DISTRONIC PLUS detects that there is a risk of a collision, you will be warned visually and
acoustically. Without your intervention, DIS-
TRONIC PLUS cannot prevent a collision. An
intermittent warning tone will then sound and
the distance warning lamp will light up in the instrument cluster. Brake immediately to
increase the distance to the vehicle driving in
front, or take evasive action, provided it is
safe to do so.
The radar sensor system is switched off auto- matically in the vicinity of radio telescope
facilities (Y page 350).
For DISTRONIC PLUS 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).
DISTRONIC PLUS is automatically deactiva-
ted if:
R you are driving slower than 25 km/h and
there is no longer a vehicle in front or
R the vehicle ahead has not been detected
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control in the speed range between 30 km/h
and 200 km/h. If a vehicle is driving in front of
you, it operates in the speed range between
0 km/h and 200 km/h.
Do not use DISTRONIC PLUS on roads with
steep gradients.
Cruise control lever With the cruise control lever, you can operate
DISTRONIC PLUS and variable SPEED-
TRONIC.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec- ted:
R LIM indicator lamp off: DISTRONIC PLUS
is selected.
R LIM indicator lamp on: variable SPEED-
TRONIC is selected. :
To store the current speed or a higher
speed
; To set the specified minimum distance
= LIM indicator lamp 174
Driving systemsDriving and parking

DISTRONIC PLUS is automatically deactiva-
ted if:
R you apply the electric parking brake or if the
vehicle is automatically secured with the
electric parking brake
R you are driving slower than 10 km/h and
there is no longer a vehicle in front, or if the vehicle in front is no longer detected
R ESP ®
intervenes or you deactivate ESP ®
R the transmission is in the P,Ror Nposition
R you switch off the radar sensor system
R you pull the cruise control lever towards
you in order to pull away and the front-
passenger door or one of the rear doors is
open
R the vehicle is skidding
R you activate Active Parking Assist
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. You will see the DIS‐
DIS‐
TRONIC TRONIC PLUS
PLUSoff
offmessage in the multifunc-
tion display for approximately five seconds.
In the Assistance menu (Y page 217) of the
on-board computer, you can select the assis-
tance graphic. :
Vehicle in front, if detected
; Distance indicator: current distance to
the vehicle in front
= Specified minimum distance to the vehi-
cle in front; adjustable
? Own vehicle
X Select the Distance display
Distance display function
using the on-board computer
(Y page 217). Tips for driving with DISTRONIC PLUS General notes
The following contains descriptions of certain
road and traffic conditions in which you must be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.
Cornering, going into and coming out of a
bend The ability of DISTRONIC PLUS to detect vehi-
cles when cornering is limited. Your vehicle
may brake unexpectedly or late.
Vehicles which are not driving in the mid- dle of their lane DISTRONIC PLUS may not detect vehicles
which are not driving in the middle of their
lane. The distance to the vehicle in front will
be too short.178
Driving systemsDriving an
d 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 deacti-
vated after approx-
imately five seconds,
and the indicator lamp
in 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 deacti-
vated after approx-
imately five seconds. The PARKTRONIC sensors are dirty or there is interference.
X Clean the PARKTRONIC sensors (Y page 294).
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
Important safety notes Active Parking Assist is only an aid. It is not a
substitute for your attention to the immediate
surroundings. The responsibility for safe
manoeuvring and parking remains with you.
Make sure that there are no persons, animals
or objects in range while manoeuvring and
parking. G
WARNING
The vehicle will veer out when parking and can take you onto sections of the oncoming lane.As a result, you may collide with other road
users. There is a risk of an accident.
When parking, pay attention to other road
users. Stop the vehicle if necessary or cancel
the Active Parking Assist parking procedure.
! If unavoidable, you should drive over
obstacles such as kerbs slowly and not at a sharp angle. Otherwise, you may damage
the wheels or tyres.
Active Parking Assist may also display spaces not suitable for parking, e.g.:
R parking or stopping prohibitions
R in front of driveways or entrances and exits
R unsuitable surfaces
Parking tips:
R on narrow roads, drive as closely as possi-
ble past the parking space.
R parking spaces that are littered, overgrown
or partially occupied by trailer drawbars
might be identified incorrectly or not at all.
R snowfall or heavy rain may lead to a parking
space being measured inaccurately.
R pay attention to the PARKTRONIC
(Y page 184) warning messages during the
parking procedure. 186
Driving systemsDriving 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 Rto
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 mfrom the rear of the vehicle
B Yellow guide line at a distance of approx-
imately 4.0 mfrom 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 systemsDriving and parking

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!
Attention Assist: Take a break!
message appears in the multifunction dis-
play.
X If necessary, take a break.
X Press the aor% 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 trees 196
Driving systemsDriving 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 display Briefly 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
197Driving 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 mbehind 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 systemsDriving 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 reversegear 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 2in 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
Blind
Spot Assist currently unavailable Spot Assist currently unavailable
See Owner's Manual 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 2in 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
199Driving and parking Z