ABS MERCEDES-BENZ A CLASS 2012 User Guide

When
Standard is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this event, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
When Adaptive is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane
marking, the system recognises certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a motor-
way.
R the system recognises solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend. Towing a trailer
Notes on towing a trailer
Important safety notes G
WARNING
The braking system can overheat if you leave
your foot on the brake pedal while driving.
This

increases the braking distance and could even cause the braking system to fail. There
is a risk of an accident.
Never use the brake pedal as a footrest. Do
not simultaneously depress both the brake
pedal

and the accelerator pedal while driving. G
WARNING
You could lose control of the vehicle/trailer
combination if it begins to swerve. The vehi-
cle/trailer combination could even overturn.
There is a risk of an accident.
On no account should you attempt to
straighten out the vehicle/trailer combina-
tion by increasing speed. Decrease your
speed and do not countersteer. Brake if nec-
essary. G
WARNING
If the maximum the permissible load for a car-
rier system is exceeded, the carrier could
come loose from the vehicle and endanger
other

road users. There is a risk of an accident
and injury.
Never exceed the permissible noseweight
when using a carrier.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
Trailer towing is not permissible on the fol-
lowing models:
R A 45 AMG 4MATIC
R Vehicles with the AMG Sports package
If you exceed the maximum permissible nose-
weight of the trailer drawbar on the ball cou-
pling, the following may become damaged:
R your vehicle
R the trailer
R the ball coupling
R the trailer tow hitch
The vehicle/trailer combination could
become unstable.
If the noseweight used is lower than the min-
imum permissible noseweight, the vehicle/ Towing a trailer
201
Driving and parking Z

Safety systems
Display messages Possible causes/consequences and
M Solutions!÷
currently unavail‐
able See Owner's
Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function, hill
start assist and ESP ®
trailer stabilisation are temporarily unavail-
able.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The
steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above

20 km/h.
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. !÷
inoperative See
Owner's Manual ABS, ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist
and
ESP®
trailer stabilisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the J, ÷, å and ! warning lamps light
up in the instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING230
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M Solutions÷
inoperative See
Owner's Manual ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilisation are not available due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the ÷ and å warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The
braking distance may thus increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Drive on carefully.
X Visit a qualified specialist workshop. T!
÷
inoperative See
Owner's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, PRE-
SAFE ®
,

the HOLD function, hill start assist and ESP ®
trailer stabi-
lisation are unavailable due to a malfunction.
The adaptive brake lights and COLLISION PREVENTION ASSIST
may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster and a warning tone sounds.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The

steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately.232
Display messages
On-board computer and displays

Safety systems
Problem Possible causes/consequences and
M SolutionsJ
The red brake system
warning
lamp is lit while
the engine is running. A
warning tone also
sounds. There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
The braking efficiency may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention

to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away ( Y page 162).
X Do not top up the brake fluid. Topping up will not rectify the
fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The

yellow ABS warning
lamp is lit while the
engine is running. ABS (Anti-lock Brake System) has been deactivated due to a fault.
BAS
(Brake Assist), COLLISION PREVENTION ASSIST, ESP ®
(Elec-
tronic Stability Program), PRE-SAFE ®
, the HOLD function, hill start
assist, the adaptive brake lights and ESP ®
trailer stabilisation are
also therefore deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The

steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will be unavailable. 258
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Problem Possible causes/consequences and
M Solutions!
The
yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, COLLISION PRE-
VENTION
ASSIST, ESP ®
, EBD (electronic brake force distribution),
PRE-SAFE ®
, the HOLD function, hill start assist, the adaptive brake
lights and ESP ®
trailer stabilisation, for example, are also deacti-
vated.
Possible causes:
R Self-diagnosis is not yet complete.
R the on-board voltage may be insufficient
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The

steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is a risk of an accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
259
On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions!
The
yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is faulty. Therefore, ABS, BAS, COLLISION PREVENTION
ASSIST,
ESP®
, PRE-SAFE ®
, the HOLD function, hill start assist, the
adaptive brake lights and ESP ®
trailer stabilisation, for example,
are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The

steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. J֌!
The red brake warning
lamp, the yellow ESP
®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are malfunctioning. Therefore, BAS, COLLISION
PREVENTION ASSIST, EBD, PRE-SAFE ®
, the HOLD function, hill
start assist, the adaptive brake lights and ESP ®
trailer stabilisa-
tion, for example, are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock, for example, if you brake hard.
The

steerability and braking characteristics may be severely affec-
ted. The braking distance may increase in an emergency braking
situation.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is an increased danger of skidding and risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.260
Warning and indicator lamps in the instrument cluster
On-board computer and displays

and a tyre pressure that is too low can signif-
icantly impair the vehicle's braking and driv-
ing
characteristics. There is a risk of accident.
Do not continue driving. Contact a qualified
specialist workshop.
i In your vehicle, you will find a sticker with
the Mercedes-Benz Service24h telephone
number, e.g. on the B-pillar on the driver's
side.
X Correct the tyre pressure if it is still at least
130

kPa (1.3 bar/19 psi) (see the fuel filler
flap for values).
X To increase the tyre pressure:
switch on
the tyre inflation compressor. X
To reduce the tyre pressure: depress
pressure release button : next to pres-
sure gauge ;.X
To remove the tyre sealant bottle from the
tyre inflation compressor, press together
the locking tabs on the yellow cap.
X Pull the tyre sealant bottle out of the tyre
inflation compressor. The filler hose stays on the tyre sealant
bottle.
X Stow the tyre sealant bottle, the tyre infla-
tion compressor and the warning triangle.
X Drive to the nearest qualified specialist
workshop

and have the tyre changed there.
X Have the tyre sealant bottle and the filler
hose replaced as soon as possible at a
qualified specialist workshop.
X Have the tyre sealant bottle replaced every
four years at a qualified specialist work-
shop. Battery (vehicle)
Important safety notes
Work on the battery, e.g. removing or instal-
ling, requires specialist knowledge and the
use of special tools. Therefore, always have
work

on the battery carried out at a qualified
specialist workshop. G
WARNING
Work carried out incorrectly on the battery
can, for example, lead to a short circuit and
damage

your vehicle's electronic system. This
can disrupt driving safety systems such as
ABS (anti-lock braking system) or ESP ®
(Elec-
tronic Stability Program).
R If ABS malfunctions, the wheels can lock
during braking. This limits the steerability
of the vehicle when braking and the braking
distance may increase. There is a risk of
accident.
R If ESP ®
malfunctions, the vehicle will not be
stabilised if it starts to skid or a wheel starts
to spin. There is a risk of accident.
You should therefore have all work involving
the battery carried out at a qualified specialist
workshop. G
WARNING
Electrostatic build-up can lead to the creation
of
sparks, which could ignite the highly explo-304
Battery (vehicle)
Breakdown assistance

sive gases of a battery. There is a risk of an
explosion.
Before
handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture is formed
when charging the battery or jump-starting
the vehicle.
Always make sure that neither you nor the
battery is electrostatically charged. Electro-
static charge is caused, for example, by:
R wearing synthetic clothing
R the friction of clothing on the seat
R pulling or sliding the battery over carpets
or other synthetic materials
R rubbing the battery with a cloth G
WARNING
During the charging process, a battery produ-
ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a
connected

battery does not come into con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jump leads.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid
contact with the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from batteries. Wash battery acid immediately with
water and seek medical attention.
H
Environmental note Batteries contain pollutants.
It

is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop or to a col-
lection

point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe

the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information.
! Always have work on the battery carried
out at a qualified specialist workshop.
Should it, in exceptional circumstances, be
absolutely necessary to disconnect the bat-
tery yourself, please observe the following:
R switch off the engine and remove the
key. Check that all the indicator lamps in
the instrument cluster are off. Otherwise,
you may damage electronic components
such as the alternator, for example.
R first, disconnect the negative terminal
clamp, followed by the positive terminal
clamp. Never swap the terminal clamps.
The vehicle electronics may otherwise be
damaged.
R on vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle. Battery (vehicle)
305
Breakdown assistance Z

R
Run in new tyres at moderate speeds for
the first 100 km
. They only reach their full
performance after this distance.
R Do not drive with tyres which have too little
tread depth. This otherwise significantly
reduces the traction on wet roads (aqua-
planing).
R Replace the tyres after six years at the lat-
est, regardless of wear.
Observe the notes on the emergency spare
wheel (Y page 332). MOExtended tyres (tyres with run-flat
characteristics)
With MOExtended tyres (tyres with run-flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tyres.
MOExtended tyres may only be used in con-
junction with an active tyre pressure loss
warning system and only on wheels specifi-
cally tested by Mercedes-Benz.
Notes

on driving with MOExtended tyres with
a flat tyre ( Y page 300).
i Vehicles with MOExtended tyres are not
equipped with a TIREFIT kit at the factory.
It is therefore recommended that you addi-
tionally equip your vehicle with a TIREFIT kit
if you fit tyres that do not feature run-flat
characteristics, e.g. winter tyres. A TIREFIT
kit can be obtained from a qualified spe-
cialist workshop. Winter operation
General notes
Have
your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Changing a wheel"
section ( Y page 324). Driving with summer tyres
At temperatures below +7 †, summer tyres
lose elasticity and therefore traction and
braking

power. Change the tyres on your vehi-
cle to M+S tyres. Using summer tyres at very
cold temperatures could cause tears to form,
thereby damaging the tyres permanently.
Mercedes-Benz cannot accept responsibility
for this type of damage. M+S tyres
G
WARNING
M+S
tyres with a tyre tread depth of less than
4 mm are not suitable for use in winter as they
do not provide sufficient traction. There is a
risk of accident.
M+S tyres with a tread depth of less than
4 mm must be replaced.
At temperatures below +7 †, use winter tyres
or all-season tyres. Both types of tyre are
identified by the M+S marking.
Only winter tyres bearing the i snowflake
symbol in addition to the M+S marking pro-
vide the best possible grip in wintry road con-
ditions. Only these tyres will allow driving
safety systems such as ABS and ESP ®
to
function optimally in winter. These tyres have
been developed specifically for driving in
snow.
Use M+S tyres of the same make and tread
on all wheels to maintain safe handling char-
acteristics.
Always observe the maximum permissible
speed specified for the M+S tyres you have
fitted.
If you fit M+S tyres that have a lower maxi-
mum permissible speed than that of the vehi-
cle, affix an appropriate warning sign in the
driver's field of vision. This can be obtained
at a qualified specialist workshop.
Under these circumstances, you should also
restrict the maximum speed of the vehicle
using permanent SPEEDTRONIC so that it 320
Winter operation
Wheels and tyres

X
Tighten the wheel bolts until they are fin-
ger-tight.
Lowering the vehicle G
WARNING
The wheels could work loose if the wheel nuts
and bolts are not tightened to the specified
tightening torque. There is a risk of accident.
Have the tightening torque immediately
checked at a qualified specialist workshop
after a wheel is changed. X
Place the ratchet ring spanner onto the
hexagon nut of the jack so that the letters
AB are visible.
X Turn the ratchet ring spanner until the vehi-
cle is once again standing firmly on the
ground.
X Place the jack to one side.
X Tighten the wheel bolts evenly in a cross-
wise pattern in the sequence indicated
(: to A). The tightening torque must be
130 Nm.
X Turn the jack back to its initial position.
X Stow the jack and the rest of the vehicle
tools in the vehicle again.
X Vehicles with AMG equipment: insert the
cover into the outer sill.
X Check the air pressure of the newly fitted
wheel and adjust accordingly.
Observe the recommended tyre pressure
(Y page 321). Wheel and tyre combinations
General notes
! For safety reasons, Mercedes-Benz rec-
ommends that you only use tyres and
wheels which have been approved by
Mercedes-Benz specifically for your vehi-
cle.
These are specially adapted to the control
systems, such as ABS or ESP ®
and are
marked as follows:
R MO = Mercedes-Benz Original
R MOE

= Mercedes-Benz Original Extended
(tyres featuring run-flat characteristics)
R MO1 = Mercedes-Benz Original (only cer-
tain AMG tyres)
Mercedes-Benz Original Extended tyres
may only be used on wheels that have been
specifically approved by Mercedes-Benz.
Only use tyres, wheels or accessories tes-
ted and approved by Mercedes-Benz. Cer-
tain characteristics, e.g. handling, vehicle
noise emissions or fuel consumption, may
otherwise be adversely affected. In addi-
tion, when driving with a load, tyre dimen-
sion variations could cause the tyres to
come into contact with the bodywork and
axle components. This could result in dam-
age to the tyres or the vehicle.
Mercedes-Benz accepts no liability for
damage resulting from the use of tyres,
wheels or accessories other than those tes-
ted and approved.
Further information about wheels, tyres
and approved combinations can be
obtained from any qualified specialist
workshop.
! Retreaded tyres are neither tested nor
recommended by Mercedes-Benz, since
previous damage cannot always be detec-
ted on retreaded tyres. As a result,
Mercedes-Benz cannot guarantee vehicle
safety if retreaded tyres are fitted. Do not
fit used tyres if you have no information
about their previous usage. Wheel and tyre combinations
329
Wheels and tyres Z