brake light MERCEDES-BENZ A CLASS 2012 User Guide

teristics may be severely impaired. Addition-
ally, further driving safety systems are deac-
tivated.
There is an increased danger of skid-
ding and accidents.
Drive on carefully. Have ABS checked imme-
diately at a qualified specialist workshop.
If ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe the information
on the ABS warning lamp ( Y page 258) and
display messages which may be shown in the
instrument cluster (Y page 230).
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the vehi-
cle when braking.
ABS works from a speed of about 8 km/h
upwards, regardless of road-surface condi-
tions. ABS works on slippery surfaces, even
when you only brake gently.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking X
If ABS intervenes:
continue to depress the
brake pedal with force until the braking sit-
uation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
The pulsating brake pedal can be an indica-
tion of hazardous road conditions, and func-
tions as a reminder to take extra care while
driving. BAS (Brake Assist)
i Observe

the "Important safety notes" sec-
tion (Y page 61). G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
BAS operates in emergency braking situa-
tions.

If you depress the brake pedal quickly,
BAS automatically boosts the braking force,
thus shortening the stopping distance.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
the adaptive Brake Assist and the distance
warning signal, which are described in the
following.
Distance warning function
Important safety notes
i
Observe

the "Important safety notes" sec-
tion for driving safety systems
(Y page 61). G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always

pay careful attention to the traffic sit-
uation and be ready to brake. 62
Driving safety systems
Safety

G
WARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always
pay careful attention to the traffic sit-
uation; do not rely on the distance warning
function alone.
Function
X To activate/deactivate:
activate or deac-
tivate the distance warning function in the
on-board computer (Y page 218).
Vehicles with a black and white multi-
function
display: when the distance warning
function is activated, the Ä symbol
appears in the status overview in the multi-
function display.
Vehicles with a colour multifunction dis-
play: when the distance warning function is
deactivated, the æ symbol appears in the
assistance graphics in the multifunction dis-
play.
The distance warning function can help you
to minimise the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision. If the distance warning func-
tion detects that there is a risk of a collision,
you will be warned visually and acoustically.
Without your intervention, the distance warn-
ing function cannot prevent a collision.
The distance warning function issues a warn-
ing at speeds:
R of around 30 km/h or more, if, over several
seconds, the distance maintained to the
vehicle travelling in front is insufficient. The
· distance warning lamp then lights up
in the instrument cluster.
R of around 7 km/h or higher, if you very
quickly approach a vehicle in front. An
intermittent warning tone will then sound, and the · distance warning lamp will
light up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions

may also cause the system to display a
warning.
With the help of the radar sensor system, the
distance warning function can detect obsta-
cles that are in the path of your vehicle for an
extended period of time.
Up to a speed of around 70 km/h, the dis-
tance warning function can also react to sta-
tionary obstacles, such as stopped or parked
vehicles.
If you approach an obstacle and the distance
warning function detects a risk of a collision,
the system will alert you both visually and
acoustically.
In particular, the detection of obstacles can
be impaired in the case of:
R dirt on the sensors or obscured sensors
R snow or heavy rain
R interference by other radar sources
R strong radar reflections, for example, in
multi-storey car parks
R a narrow vehicle travelling in front, e.g. a
motorcycle
R a vehicle travelling in front on a different
line
Following damage to the front end of the vehi-
cle, have the configuration and operation of
the radar sensor checked at a qualified spe-
cialist workshop. This also applies to colli-
sions at slow speeds where there is no visible
damage to the front of the vehicle. Driving safety systems
63Safety Z

Adaptive brake lamps
If you brake sharply from a speed of more
than
50 km/h or if braking is assisted by BAS
or adaptive Brake Assist, the brake lamps
flash rapidly. In this way, traffic travelling
behind you is warned in an even more notice-
able manner.
If you brake sharply from a speed of more
than 70 km/h to a standstill, the hazard warn-
ing lamps are activated automatically. If the
brakes are applied again, the brake lamps
light up continuously. The hazard warning
lamps switch off automatically if you travel
faster than 10 km/h. You can also switch off
the hazard warning lamps using the hazard
warning switch button (Y page 108).
i Adaptive brake lamps are only available in
certain countries. ESP
®
(Electronic Stability Program)
General notes i
Observe
the "Important safety notes" sec-
tion (Y page 61).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tyres
and the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilise the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilise the vehicle during braking.
ETS/4ETS (Electronic Traction System) i
Observe
the "Important safety notes" sec-
tion (Y page 61).
ETS/4ETS traction control is part of ESP ®
.
ETS brakes the drive wheels individually if
they spin. This enables you to pull away and
accelerate on slippery surfaces, for example if the road surface is slippery on one side. In
addition, more drive torque is transferred to
the wheel or wheels with traction.
ETS remains active when you deactivate
ESP
®
.
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilise
the vehicle. In addition, other driving
safety systems are switched off. This increa-
ses the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop.
! When testing the electric parking brake
on a braking dynamometer, switch off the
ignition. Application of the brakes by
ESP ®
may otherwise destroy the brake sys-
tem.
! Vehicles with 4MATIC: switch off the igni-
tion when the electric parking brake is
being tested using a dynamometer.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on
a 2-axle dynamometer. Before operating
the vehicle on such a dynamometer, please
consult a qualified specialist workshop.
You could otherwise damage the drive train
or the brake system.
! Do not tow vehicles with 4MATIC with the
front or rear axle raised.
Vehicles without 4MATIC: when towing your
vehicle with the front axle raised, it is impor-
tant that you observe the notes on
ESP ®
(Y page 312).
Vehicles with 4MATIC: when towing your
vehicle with both axles on the ground, it is
important that you observe the notes on
ESP ®
(Y page 312). Driving safety systems
65
Safety Z

i
Activate ESP ®
as soon as the situations
described
above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ®X
To activate SPORT handling mode:
briefly press button :.
The M handling mode warning lamp in
the instrument cluster lights up. The
SPORT handling mode message appears
in the multifunction display.
X To deactivate SPORT handling mode:
briefly press button :.
The M handling mode warning lamp in
the instrument cluster goes out.
X To deactivate ESP ®
:
press button : until
the å ESP ®
OFF warning lamp lights up
in the instrument cluster.
The ÷OFF message appears in the mul-
tifunction display.
X To activate ESP ®
:
briefly press button :.
The å ESP ®
OFF warning lamp in the
instrument cluster goes out. The ÷
ESP ®
ON message appears in the multifunc-
tion display.
Characteristics of activated SPORT han-
dling mode
If

SPORT handling mode is activated and one
or more wheels start to spin, the ÷ ESP ®
warning lamp in the instrument cluster flashes. ESP
®
only stabilises the vehicle to a
limited degree.
When SPORT handling mode is activated:
R ESP ®
only improves driving stability to a
limited degree.
R traction control is still activated.
R engine torque is restricted to a limited
degree and the drive wheels are able to
spin.
The

spinning of the wheels results in a cut-
ting action for better traction on loose sur-
faces.
R ESP ®
still provides support when you
brake.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster does not flash. In such
situations, ESP ®
will not stabilise the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin.
The spinning of the wheels results in a cut-
ting action for better traction on loose sur-
faces.
R traction control is still activated.
R PRE-SAFE ®
is no longer available; nor is it
activated if you brake firmly with assis-
tance from ESP ®
.
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
.
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
.
R ESP ®
still provides support when you
brake. Driving safety systems
67
Safety Z

Deactivating/activating ESP
®
(except
AMG vehicles) Important safety notes
You can select between the following states
of ESP
®
:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilises the vehicle. There is an increased risk
of skidding and an accident.
Only
deactivate ESP ®
in the situations descri-
bed in the following.
It may be best to deactivate ESP ®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
i Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehi-
cle if the vehicle starts to skid or a wheel
starts to spin.
Deactivating/activating ESP ®
You can deactivate or activate ESP ®
via the
on-board computer.
X To deactivate: (Y page 218).
The å ESP ®
OFF warning lamp in the
instrument cluster lights up.
X To activate: (Y page 218).
The å ESP ®
OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP ®

is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster flashes. In such situa-
tions, ESP ®
will not stabilise the vehicle. If you deactivate ESP
®
:
R ESP ®
no longer improves driving stability.
R engine torque is no longer limited and the
drive wheels are able to spin.
The

spinning of the wheels results in a cut-
ting action for better traction on loose sur-
faces.
R traction control is still activated.
R ESP ®
still provides support when you
brake.
ESP ®
trailer stabilisation General notes
If your vehicle/trailer combination begins to
lurch, ESP
®
assists you in this situation.
ESP ®
slows the vehicle down by braking and
limiting the engine output until the vehicle/
trailer combination has stabilised.
Important safety notes G
WARNING
If road and weather conditions are poor,
trailer
stabilisation will not be able to prevent
the vehicle/trailer combination from swerv-
ing. Trailers with a high centre of gravity can
tip over before ESP ®
can detect this. There is
a risk of an accident.
Always adapt your driving style to the prevail-
ing road and weather conditions.
If your vehicle/trailer combination begins to
lurch, you can only stabilise the vehicle/
trailer combination by depressing the brake
firmly.
ESP ®
trailer stabilisation is active above
speeds of about 65 km/h.
ESP ®
trailer stabilisation does not work if
ESP ®
is deactivated or disabled because of a
malfunction. 68
Driving safety systems
Safety

Problem Possible causes/consequences and
M SolutionsThe engine cannot be
started using the key. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 304).
or
X Jump-start the vehicle (Y page 308).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the key. The steering lock is mechanically blocked.
X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. Doors
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the automatic transmission out of
parking position P.
R shift the manual transmission into neutral.
R start the engine.
There is a risk of an accident and injury.
When
leaving the vehicle, always take the key
with you and lock the vehicle. Never leave
children or animals unattended in the vehicle.
Always keep the key out of reach of children. G
WARNING
If persons (particularly children) are exposed
to heat or cold for a prolonged period, there
is

a risk of serious or even fatal injuries. Never
leave persons (particularly children) unatten-
ded in the vehicle.
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside.

People in the vehicle can no longer get
out, e.g. in hazardous situations. There is a
risk of injury.
Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld-
erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked with the key,
then the double lock function is activated as
standard. You can deactivate the double lock
function by deactivating the interior motion
sensor (Y page 70). The doors can then be
opened from the inside after the vehicle has
been locked from the outside. The anti-theft Doors
79
Opening and closing Z

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 2 or start the engine.
X Turn the light switch to L.
The green L indicator 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 2 or start the
engine.
X Turn the light switch to L or Ã.
X Press the N button.
The

green N indicator lamp in the instru-
ment cluster lights up.
X To switch off the front foglamps: press
the N button.
The

green N indicator 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 2 or start
the engine.
X Turn the light switch to L or Ã.X
Press the R button.
The yellow R indicator lamp in the
instrument cluster lights up.
X To switch off the rear foglamp:
press the
R button.
The yellow R indicator 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 T side lamps for several
hours. If possible, switch on the X right
or the W left 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 lighting
Lights and windscreen wipers

The blue
K indicator lamp in the instru-
ment cluster lights up when the main-beam
headlamps are switched on.
X To switch off the main-beam head-
lamps:

move the combination switch back
to its normal position.
The blue K indicator lamp in the instru-
ment cluster goes out.
i Vehicles with Adaptive Highbeam Assist:
when Adaptive Highbeam Assist is active,
it controls activation of the main-beam
headlamps

(Y page 110).
Headlamp flasher X
To switch on: turn the key in the ignition
lock to position 1 or 2,

or start the engine.
X Pull the combination switch in the direction
of arrow =. Hazard warning lamps
The hazard warning lamps switch on auto-
matically if:
R
an airbag is deployed or
R the vehicle decelerates rapidly from a
speed

of more than 70 km/h and comes to
a standstill
X To switch on the hazard warning lamps:
press button :.
All turn signals flash. If you now switch on
a

turn signal using the combination switch, only the turn signal lamp on the corre-
sponding side of the vehicle will flash.
X To switch off the hazard warning
lamps: press button :.
The hazard warning lamps switch off auto-
matically if the vehicle reaches a speed of
over 10 km/h

again after a full brake appli-
cation.
i The hazard warning lamps still operate if
the ignition is switched off. Headlamp cleaning system
If the "Wipe with washer fluid" function is
operated five times ( Y page 117) while the
lights are on and the engine is running, the
headlamps are cleaned automatically. When
you switch off the ignition, the automatic
headlamp

cleaning system is reset and count-
ing is resumed from 0. Intelligent Light System
General notes The Intelligent Light System is a system that
adjusts the headlamps automatically to suit
the

prevailing driving and weather conditions.
It offers advanced functions for improved illu-
mination of the road surface, e.g. depending
on the vehicle speed or weather conditions.
The system includes the active light function,
cornering light function, motorway mode and
extended range foglamps. The system is only
active when it is dark.
You can activate or deactivate the "Intelligent
Light System" using the on-board computer
(Y page 221). 108
Exterior lightingLights and windscreen wipers

Overview of bulb replacement – bulbs
You can replace the following bulbs. The
details for the bulb type can be found in the
legend. Halogen headlamps
:
Turn signal lamp: PY 21 W
; Main-beam headlamp/side lamp/park-
ing lamp: H15 55 W/15 W
= Dipped-beam headlamp: H7 55 W Vehicles with Intelligent Light System
:
Cornering lamp: H7 55 W Tail lamp (halogen headlamps)
:
Reversing lamp: W 16 W
; Turn signal lamp: PY 21 W
= Tail lamp/brake lamp: W 16 W
? Rear foglamp: W 16 W
A Tail lamp: W 16 W Replacing the front bulbs
Fitting/removing the cover on the front
wheel arch You must remove the cover from the front
wheel housing before you can change the
front bulbs.
X
To remove: switch off the lights.
X Turn the front wheels inwards.
X Turn rotary knob : through 90°.
Cover ; is released.
X Push cover ; down.
X To fit: push cover ; up.
X Turn rotary knob : through 90°.
Cover ; is locked. Replacing bulbs
113
Lights and windscreen wipers Z

Right-hand side trim panel
X
To open: turn release knob : 90° in the
direction
of the arrow and remove side trim
panel ;.
X To close:
insert side trim panel ; and turn
release knob : 90° in the opposite direc-
tion to the arrow.
Tail lamps X
Switch off the lights.
X Open the luggage compartment.
X Open the side trim panel ( Y page 115).X
Release and remove connector ;.
X Unscrew wing nut :
and remove the lamp
cluster. Lamp cluster
X
Remove plastic nut ? using a suitable
item, e.g. a coin.
X Release attachments =.
X Remove the bulb holder from the lamp clus-
ter. Bulb holder
A
Tail lamp/brake lamp
B Reversing lamp
C Rear foglamp
D Tail lamp
E Turn signals
X Tail lamp/brake lamp/rear foglamp/
reversing lamp: remove the correspond-
ing bulb from the bulb holder.
X Insert the new bulb into the bulb holder.
X Turn signal lamp: lightly press the bulb
into the bulb holder, turn it anti-clockwise
and remove it from the bulb holder. 116
Replacing bulbs
Lights and windscreen wipers