brake MERCEDES-BENZ A CLASS 2012 Owner's Manual

Adaptive Brake Assist
i
Observe the "Important safety notes" sec-
tion for driving safety systems
(Y page 61). G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions. In these cases, Adaptive Brake Assist
may not intervene. There is a risk of an acci-
dent.
Always

pay careful attention to the traffic sit-
uation and be ready to brake. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R to stationary obstacles
R when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always

pay careful attention to the traffic sit-
uation and be ready to brake.
Adaptive Brake Assist aids you in braking dur-
ing hazardous situations at speeds above
30 km/h and uses the radar sensor system
to evaluate the traffic situation.
With the help of a sensor system, adaptive
Brake Assist can detect obstacles that are in
the path of your vehicle for an extended
period of time.
Should you approach an obstacle and adap-
tive Brake Assist has detected a risk of colli-
sion, adaptive Brake Assist calculates the
braking force necessary to avoid a collision.
Should you apply the brakes forcefully, adap-
tive Brake Assist will automatically increase
the braking force to a level suitable for the
traffic conditions. X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal
R there

is no longer any danger of a collision
R no obstacle is detected in front of your
vehicle
Adaptive Brake Assist is then deactivated.
Vehicles with PRE-SAFE ®
: if adaptive Brake
Assist requires particularly high brake pres-
sure, preventative passenger protection
measures (PRE-SAFE ®
) are deployed simul-
taneously.
Up to vehicle speeds of around 250 km/h,
adaptive Brake Assist is capable of reacting
to moving objects that have already been rec-
ognised as such at least once over the period
of observation. Adaptive Brake Assist does
not react to stationary obstacles.
If adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
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
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. 64
Driving safety systems
Safety

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

EBD (electronic brake force distribu-
tion)
i Observe
the "Important safety notes" sec-
tion for driving safety systems
(Y page 61). G
WARNING
If EBD has malfunctioned, the rear wheels can
still lock, e.g. under full braking. This increa-
ses the risk of skidding and an accident.
You should therefore adapt your driving style
to

the different handling characteristics. Have
the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps ( Y page 258) as well as dis-
play messages (Y page 232).
EBD monitors and controls the brake pres-
sure on the rear wheels to improve driving
stability while braking. ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and

offers increased braking comfort. In addi-
tion to the braking function, ADAPTIVE BRAKE
also has the HOLD function (Y page 180) and
hill start assist ( Y page 145). For further
information, see Driving tips (Y page 166). STEER CONTROL
STEER
CONTROL helps you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilisation.
This steering support is provided in particular
if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake
R the vehicle starts to skid.
If there is an ESP ®
malfunction, you will not
receive any steering support from STEER CONTROL. Power steering will, however, con-
tinue to function.
Anti-theft systems
Immobiliser
The immobiliser prevents your vehicle from
being started without the correct key.
X To activate:
remove the key from the igni-
tion lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the key
with
you and lock the vehicle. The engine can
be started by anyone with a valid key that is
left inside the vehicle.
i The immobiliser is always deactivated
when you start the engine. ATA (Anti-Theft Alarm system)
X
To prime: lock the vehicle with the key.
Indicator lamp : flashes. The alarm sys-
tem is primed after approximately
15 seconds.
X To deactivate:
unlock the vehicle with the
key.
or
X Insert the key into the ignition lock. Anti-theft systems
69
Safety Z

Useful information
i This Owner's Manual describes all mod-
els,
series and optional equipment for your
vehicle that were available at the time of
going to press. National variations are pos-
sible. Note that your vehicle may not be
equipped with all of the functions descri-
bed. This is also the case for systems and
functions relevant to safety.
i Read the information on qualified special-
ist workshops: (Y page 24). Key
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. G
WARNING
If you attach heavy or large objects to the key,
the
key could be unintentionally turned in the
ignition lock. This could cause the engine to
be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to
the key. Remove any bulky keyrings before
inserting the key into the ignition lock.
! Keep the key away from strong magnetic
fields. Otherwise, the remote control func-
tion could be affected.
Strong magnetic fields can occur in the
vicinity of powerful electrical installations.
Do not keep the key:
R with electronic devices, e.g. a mobile
phone or another key
R with metallic objects, e.g. coins or metal
film
R inside metallic objects, e.g. a metal case
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
alarm system is triggered if the door is
opened from the inside. Switch off the alarm
(Y page 69). 74
Key
Opening and closing

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