sensor MERCEDES-BENZ A-CLASS HATCHBACK 2012 Owner's Manual

even if the light sensor does not sense dark
ambient light conditions. This is advanta-
geous when there is fog or rain.
X To switch on the dipped-beam head-
lamps: turn the key in the ignition lock to
position 2or start the engine.
X Turn the light switch to L.
The green Lindicator lamp in the instru-
ment cluster lights up.
Foglamps
In conditions where visibility is poor due to
fog, snow or rain, the foglamps improve visi-
bility as well as making it easier for other road
users to see you. They can be operated
together with the side lamps or together with the side lamps and dipped-beam headlamps.
X To switch on the foglamps: turn the key
in the ignition lock to position 2or start the
engine.
X Turn the light switch to LorÃ.
X Press the Nbutton.
The green Nindicator lamp in the instru-
ment cluster lights up.
X To switch off the front foglamps: press
the N button.
The green Nindicator lamp in the instru-
ment cluster goes out.
Only vehicles with front foglamps are equip-
ped with the "Foglamp" function; for how to
operate the foglamps on vehicles with the
Intelligent Light System (Y page 109).
Rear foglamp
The rear foglamp improves the visibility of
your vehicle in heavy fog for the following
traffic. Please observe the country-specific
laws on the use of rear foglamps.
X To switch on the rear foglamp: turn the
key in the ignition lock to position 2or start
the engine.
X Turn the light switch to LorÃ. X
Press the Rbutton.
The yellow Rindicator lamp in the
instrument cluster lights up.
X To switch off the rear foglamp: press the
R button.
The yellow Rindicator lamp in the
instrument cluster goes out.
i Vehicles with bi-xenon headlamps or the
Intelligent Light System: when the rear fog- lamp is switched on, the lower 15 LEDs of
the brake lamp in the tail lamp switch off
due to a legal requirement: for right-hand
traffic only in the left-hand tail lamp and for left-hand traffic only in the right-hand tail
lamp.
Side lamps ! If the battery has been excessively dis-
charged, the side lamps or parking lamps
are automatically switched off to enable
the next engine start. Always park your
vehicle safely and sufficiently lit according
to legal standards. Avoid the continuous
use of the Tside lamps for several
hours. If possible, switch on the Xright
or the Wleft parking lamp.
X To switch on: turn the light switch to T.
Depending on the equipment level, the
green indicator lamp or the scale illumina-
tion in the instrument cluster light up.
Parking lamps
Switching on the parking lamps ensures the
corresponding side of the vehicle is illumina-
ted.
X To switch on the parking lamps: the key
is not in the ignition lock or it is in posi-
tion 0.
X Turn the light switch to W(left-hand side
of the vehicle) or X(right-hand side of
the vehicle). 106
Exterior lightingLights and windscreen wipers

main-beam headlamps will not be deactivated
or activated regardless. There is a risk of an
accident.
Always carefully observe the traffic conditions
and switch off the main-beam headlamps in
good time.
You can use this function to set the head-
lamps to change between dipped beam and
main beam automatically. The system recog-
nises vehicles with their lights on, either
approaching from the opposite direction or
travelling in front of your vehicle, and conse-
quently switches the headlamps from main
beam to dipped beam.
The system automatically adapts the dipped- beam headlamp range depending on the dis-
tance to the other vehicle. Once the system
no longer detects any other vehicles, it reac-
tivates the main-beam headlamps.
The system's optical sensor is located behind
the windscreen near the overhead control
panel. X
To activate: activate the Adaptive High-
beam Assist function using the on-board
computer (Y page 222).
X Turn the light switch to Ã.X
Press the combination switch beyond the
pressure point in the direction of
arrow :(Ypage 107).
The _ indicator lamp in the multifunc-
tion display lights up when it is dark and the light sensor activates the dipped-beam
headlamps.
If you are driving at speeds above 45 km/h:
The headlamp range is set automatically
depending on the distance between the
vehicle and other road users.
If you are driving at speeds above 55 km/h and no other road users are recognised:
The main-beam headlamps are switched on
automatically. The Kindicator lamp in
the instrument cluster also lights up.
If you are driving at speeds below 45 km/h or other road users are recognised or the
roads are adequately lit:
The main-beam headlamps are switched off
automatically. The Kindicator lamp in
the instrument cluster goes out. The _
indicator lamp in the multifunction display
remains lit.
X To deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the multifunc-
tion display goes out. Headlamps misted up on the inside
The headlamps may mist up on the inside if
there is high atmospheric humidity.
X Switch on the lights and drive off.
The level of moisture diminishes, depend-
ing on the length of the journey and the
weather conditions (humidity and temper-
ature).
If the level of moisture does not diminish:
X Have the headlamps checked at a qualified
specialist workshop. 110
Exterior lightingLights and windscreen wipers

Combination switch
1
$ Windscreen wipers off
2 Ä Intermittent wipe, low (rain sensor
set to low sensitivity)
3 Å Intermittent wipe, high (rain sensor
set to high sensitivity)
4 ° Continuous wipe, slow
5 ¯ Continuous wipe, fast
B í Single wipe/ îto wipe the wind-
screen using washer fluid
X Turn the key to position 1or 2in the ignition
lock.
X Turn the combination switch to the corre-
sponding position.
! Vehicles with a rain sensor: if the wind-
screen becomes dirty in dry weather con-
ditions, the windscreen wipers may be acti-
vated inadvertently. This could damage the windscreen wiper blades or scratch the
windscreen.
For this reason, you should always switch
off the windscreen wipers in dry weather.
Vehicles with a rain sensor: in theÄor
Å position, the appropriate wiping fre-
quency is automatically set according to the
intensity of the rain. In the Åposition, the
rain sensor is more sensitive than in the Ä
position, causing the windscreen wipers to
wipe more frequently.
If the wiper blades are worn, the windscreen
will no longer be wiped properly. This could
prevent you from observing the traffic condi-
tions. Replace the wiper blades twice a year,
ideally in spring and autumn. Switching the rear window wiper on/
off Combination switch
:
è Switch
2 ô To wipe with washer fluid
3 ITo switch on intermittent wiping
4 0To switch off intermittent wiping
5 ô To wipe with washer fluid
X Turn the key to position 1or 2in the ignition
lock.
X Turn switch :on the combination switch
to the corresponding position.
When the rear window wiper is switched on,
the icon appears in the instrument cluster. Replacing the wiper blades
Important safety notes G
WARNING
If the windscreen wipers begin to move while
you are changing the wiper blades, you can be trapped by the wiper arm. There is a risk of
injury.
Always switch off the windscreen wipers and
ignition before changing the wiper blades.
! To avoid damaging the windscreen wiper
blades, make sure that you touch only the
wiper arm of the windscreen wiper.
! Never open the bonnet/tailgate if a wiper
arm is folded away from the windscreen/
rear window. Windscreen wipers
117Lights and windscreen wipers Z

Permanent SPEEDTRONIC remains active,
even if variable SPEEDTRONIC is deactivated.
You cannot exceed the stored limit speed,
even if you depress the accelerator pedal
beyond the pressure point (kickdown). DISTRONIC PLUS
Important safety notes G
WARNING
DISTRONIC PLUS does not react to:
R people or animals
R stationary obstacles on the road, e.g. stop-
ped or parked vehicles
R oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. G
WARNING
DISTRONIC PLUS cannot always clearly iden- tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may:
R give an unnecessary warning and then
brake the vehicle
R neither give a warning nor intervene
R accelerate unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS. G
WARNING
DISTRONIC PLUS brakes your vehicle with up to 40% of the maximum braking force. If this
braking force is insufficient, DISTRONIC PLUS
warns you visually and audibly. There is a risk
of an accident.
In such cases, apply the brakes yourself and
try to take evasive action. !
If DISTRONIC PLUS or the HOLD function
is activated, the vehicle brakes automati-
cally in certain situations. To prevent dam-
age to the vehicle, deactivate DISTRONIC
PLUS and the HOLD function in the follow- ing or other similar situations:
R when towing the vehicle
R in the car wash
If you fail to adapt your driving style, DIS-
TRONIC PLUS can neither reduce the risk of
an accident nor override the laws of physics. DISTRONIC PLUS cannot take road and
weather conditions or traffic conditions into
account. DISTRONIC PLUS is only an aid. You
are responsible for the distance to the vehicle
in front, for vehicle speed, for braking in good time, and for staying in the lane.
Do not use DISTRONIC PLUS:
R in road and traffic conditions which do not
allow you to maintain a constant speed
(e.g. in heavy traffic or on winding roads).
R on smooth or slippery roads. Braking or
accelerating can cause the drive wheels to
lose traction and the vehicle could then
skid.
R when there is poor visibility, e.g. due to fog,
heavy rain or snow.
DISTRONIC PLUS may not detect narrow
vehicles driving in front, e.g. motorcycles, or
vehicles driving on a different line.
In particular, the detection of obstacles can
be impaired by:
R dirt on the sensors or anything else cover-
ing the sensors
R snow or heavy rain
R interference by other radar sources
R the possibility of strong radar reflections,
for example, in multi-storey car parks
If DISTRONIC PLUS no longer detects a vehi-
cle in front, it may unexpectedly accelerate to the speed stored. Driving systems
173Driving and parking Z

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

i
If you do not depress the accelerator
pedal within a few seconds, RACE START is cancelled. The multifunction display shows
the RACE START cancelled
RACE START cancelled message.
X Fully depress the accelerator pedal.
The engine speed is increased.
The RACE START Release brake to RACE START Release brake to
start
start message appears in the multifunc-
tion display.
i If the brake pedal is not released after a
short while, RACE START is cancelled. The
multifunction display shows the RACE
RACE
START cancelled START cancelled message.
X Take your foot off the brake, but keep the
accelerator pedal depressed.
The vehicle pulls away at maximum accel-
eration.
The RACE RACE START
START active
active message appears
in the multifunction display.
RACE START is deactivated when the vehicle
reaches a speed of approximately 50 km/h.
Drive program Sis activated. SPORT handling
mode remains activated.
RACE START is deactivated immediately if
you release the accelerator pedal during
RACE START or if any of the activation condi-
tions are no longer fulfilled. The RACE
RACESTART
START
not possible
not possible orRACE START cancelled
RACE START cancelled
message appears in the multifunction dis-
play.
i After using it several times in short suc-
cession, RACE START will be unavailable
until a certain distance has been driven. 4MATIC (permanent all-wheel drive)
4MATIC ensures that all four wheels are per-
manently driven. Together with ESP ®
, it
improves the traction of your vehicle when-
ever a drive wheel spins due to insufficient
grip.
If you fail to adapt your driving style, 4MATIC
can neither reduce the risk of accident nor
override the laws of physics. 4MATIC cannot take account of road, weather and traffic con-
ditions. 4MATIC is only an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time, and for staying in the lane.
If a drive wheel spins due to insufficient grip:
R when pulling away, only depress the accel-
erator pedal as far as is necessary.
R accelerate less when driving.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz implied warranty. All
wheels must remain either on the ground or be fully raised. Observe the instructions for
towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tyres (M+S tyres), with snow
chains if necessary. PARKTRONIC
Important safety notes PARKTRONIC is only an aid. It is not a substi-
tute for your attention to the immediate sur-
roundings. 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.
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars. PARK-
TRONIC does not detect such objects when they are in the immediate vicinity of the
vehicle. You could damage the vehicle or
the objects.
The sensors may not detect snow and
objects which absorb ultrasonic sources.
Ultrasonic sources, such as an automatic
car wash, a lorry's compressed-air brakes 182
Driving systemsDriving and parking

or a pneumatic drill, could cause PARK-
TRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically if
you:
R switch on the ignition
R shift to position D,Ror Non vehicles with
automatic transmission
R release the electric parking brake
PARKTRONIC is deactivated at speeds above
18 km/h. It is reactivated at lower speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
Range of the sensors General notes
PARKTRONIC does not take into account
obstacles located:
R below the detection range, e.g. persons,
animals or objects
R above the detection range, e.g. overhang-
ing loads, tail sections or loading ramps of
goods vehicles :
Example: sensors in the front bumper,
left-hand side Side view
Top view
The sensors must be free of dirt, ice and
slush. Otherwise, they may not function cor-
rectly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y page 294).
Front sensors Centre Approx. 100 cm
Corners Approx. 60 cm
Rear sensors
Centre Approx. 120 cm
Corners Approx. 80 cm
Minimum distance
Centre Approx. 20 cm
Corners Approx. 20 cm
If there is an obstacle within this range, the
relevant warning displays light up and a warn- ing tone sounds. If the distance falls below
the minimum, the distance may no longer be
shown. Driving systems
183Driving and parking Z

Warning displays
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is located
on the dashboard above the centre air vents.
The warning display for the rear area is loca-
ted on the roof lining in the rear compart-
ment. Warning display for the front area
:
Segments on the left-hand side of the
vehicle
; Segments on the right-hand side of the
vehicle
= Segments showing operational readiness
The warning display for each side of the vehi-
cle is divided into five yellow and two red seg- ments. PARKTRONIC is operational if yellow
segments showing operational readiness =
light up.
The gear lever position or the transmission
position of the automatic transmission and
the direction in which the vehicle is rolling
determine which warning display is active
when the engine is running. Manual transmission: Gear lever posi-
tion Warning display
Forwards gear
or
Neutral
Front area activated
Reverse gear, or
the vehicle is rolling
backwards Rear and front areas
activated
Automatic transmission:
Transmission
position Warning display
D
Front area activated
R,
Nor the vehicle
is rolling back-
wards Rear and front areas
activated
P
No areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
From the:
R sixth segment onwards, you will hear an
intermittent warning tone for approx-
imately two seconds.
R seventh segment onwards, you will hear a
warning tone for approximately two sec-
onds. This indicates that you have now
reached the minimum distance. 184
Driving systemsDriving and 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