service MERCEDES-BENZ A-CLASS HATCHBACK 2012 User Guide

G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk of an accident.
Do not switch off the ignition while driving. G
WARNING
Modifications to electronic components, their software as well as wiring could effect their
function and/or the operation of other net-
worked components. This could in particular
also be the case for systems relevant to
safety. They might not function properly any
more and/or jeopardise the operational
safety of the vehicle. There is an increased
risk of an accident and injury.
Do not attempt to modify the wiring as well as
electronic components or their software.
Always have work on electrical and electronic components carried out at a qualified special-
ist workshop.
There is a risk of damage to the vehicle if:
R the vehicle becomes stuck, e.g. on a high
kerb or an unpaved road
R you drive too fast over an obstacle, e.g. a
kerb or a hole in the road
R a heavy object strikes the undercarriage or
parts of the chassis.
In situations like this, the body, the undercar- riage, chassis parts, wheels or tyres could be
damaged without the damage being visible.
Components damaged in this way can unex-
pectedly fail or, in the case of an accident, no
longer withstand the strain they are designed
to.
If the underbody panelling is damaged, com-
bustible materials such as leaves, grass or
twigs can gather between the underbody and the underbody panelling. If these materials
come in contact with hot parts of the exhaust system for an extended period, they can
catch fire.
Have the vehicle checked and repaired imme-
diately at a qualified specialist workshop. If on
continuing your journey you notice that driv-
ing safety is impaired, pull over and stop the
vehicle immediately, paying attention to road and traffic conditions. In such cases, visit a
qualified specialist workshop. Declarations of conformity
Wireless vehicle components The following information applies to all com-
ponents of the vehicle and the COMAND sys-
tem which receive and/or transmit radio
waves:
The components of this vehicle which receive
and/or transmit radio waves are compliant
with the basic requirements and other rele-
vant provisions of Directive 1999/5/EC. You can obtain further information from any
Mercedes-Benz Service Centre.
Electromagnetic compatibility The electromagnetic compatibility of the vehi-
cle components has been checked and certi-
fied according to the currently valid version of Directive 72/245/EE Cor the equivalent ECE
Regulation ECE-R 10. Diagnostics connection
The diagnostics connection is only intended
for the connection of diagnostic equipment at
a qualified specialist workshop. G
WARNING
If you connect equipment to a diagnostics
connection in the vehicle, it can affect the
operation of the vehicle systems. This may
affect the operating safety of the vehicle.
There is a risk of an accident.
Do not connect any equipment to a diagnos-
tics connection in the vehicle. Introduction
23 Z

G
WARNING
Objects in the driver's footwell can restrict the pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle is
jeopardised. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Fit the floormats
securely and as specified in order to ensure
sufficient clearance for the pedals. Do not use loose floormats.
! If the engine is switched off and equip-
ment on the diagnostics connection is
used, the starter battery may discharge.
Connecting equipment to the diagnostics
connection can lead to emissions monitoring
information being reset, for example. This
may lead to the vehicle failing to meet the
requirements of the next emissions test dur-
ing the main inspection. Qualified specialist workshop
A qualified specialist workshop has the nec-
essary special skills, tools and qualifications
to correctly carry out any necessary work on
your vehicle. This particularly applies to work relevant to safety.
Observe the notes in the Service Booklet.
Always have the following work carried out at a qualified specialist workshop:
R work relevant to safety
R service and maintenance work
R repair work
R modifications, installations and conver-
sions
R work on electronic components
Mercedes-Benz recommends that you use a
Mercedes-Benz Service Centre. Vehicle registration
Mercedes-Benz may ask its Service Centres
to carry out technical inspections on certain
vehicles. The quality or safety of the vehicle is
improved as a result of the inspection.
Mercedes-Benz can only inform you about
vehicle checks if it has your registration data.
It is possible that your vehicle has not yet
been registered in your name in the following
cases:
R if your vehicle was not purchased at an
authorised specialist dealer.
R if your vehicle has not yet been examined at
a Mercedes-Benz Service Centre.
It is advisable to register your vehicle with a
Mercedes-Benz Service Centre.
Inform Mercedes-Benz as soon as possible
about any change in address or vehicle own-
ership. Correct use
If you remove any warning stickers, you or
others could fail to recognise certain dangers. Leave warning stickers in position.
Observe the following information when driv-
ing your vehicle:
R the safety notes in this manual
R the technical data in this manual
R traffic rules and regulations
R laws and safety standards pertaining to
motor vehicles Implied warranty
! Follow the instructions in this manual
about the proper operation of your vehicle
as well as about possible vehicle damage.
Damage to your vehicle that arises from
culpable contraventions against these
instructions are not covered either by
Mercedes-Benz implied warranty or by the
New or Used-Vehicle Warranty. 24
Introduction

Data stored in the vehicle
A number of electronic components in your
vehicle contain data memories.
These data memories temporarily or perma-
nently store technical information about:
R the vehicle's operating state
R events
R faults
This technical information generally docu-
ments the condition of a component, a mod-
ule, a system or an environment.
These are, for example:
R operating conditions of system compo-
nents. This includes, e.g. fluid levels.
R status messages from the vehicle and from
individual vehicle components. This
includes, e.g. number of wheel revolu-
tions/speed, deceleration, lateral acceler-
ation.
R malfunctions and faults in important sys-
tem components. This includes, e.g. lights,
brakes.
R reactions of the vehicle in special driving
situations. This includes, e.g. deployment
of an airbag, intervention of stability control
systems.
R environmental conditions. This includes,
e.g. the outside temperature.
This data is exclusively technical in nature
and is used to:
R assist in the detection and rectification of
faults and defects
R optimise vehicle functions
The data cannot be used to trace the vehicle's movements over distances travelled.
When your vehicle is serviced, this technical
information can be read out from the event
and fault memory.
Services include:
R repairs
R service processes R
warranty claims
R quality assurance
The information is read out by authorised
employees of the service network (including
manufacturers) using special diagnostic devi-
ces. You can find more information there if
necessary.
After a fault has been rectified, the informa-
tion in the fault memory is deleted or consec- utively overwritten.
In normal vehicle operation, situations may
arise in which this technical data could
become personal in nature in conjunction
with other information and, if necessary, on
consultation of an approval official.
Examples include:
R accident reports
R vehicle damage
R witness testimonies
Further additional features which are con-
tractually agreed with the customer likewise
allow specific vehicle data to be obtained
from the vehicle. Such additional features
include vehicle locating in an emergency, for
example. Copyright information
General notes
You can find information on licences for free
and open-source software used in your vehi-
cle and its electronic components on the fol- lowing website:
http://www.mercedes-benz.com/
opensource Int
roduction
25 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). Occupant safety
Important safety notes
G
WARNING
If service work is not carried out correctly, the operating safety of your vehicle may be affec-
ted. This could cause you to lose control of
your vehicle and cause an accident. More-
over, the safety systems may no longer be
able to protect you or others as they are
designed to do.
Always have service work carried out at a
qualified specialist workshop. G
WARNING
Modifications to or work performed incor-
rectly on the following parts can result in the
restraint systems not functioning as intended:
R the restraint system, consisting of seat
belts and their anchorage points, belt ten-
sioners, belt force limiters and airbags
R the wiring
R networked electronic systems
Airbags and belt tensioners could fail to
deploy or be triggered in an accident despite
the deceleration force being sufficient to trig-
ger the systems, or could be triggered unin-
tentionally. For this reason, never make any
modifications to the restraint systems.
Therefore, you must not tamper with elec-
tronic components or their software. The seat belts, together with SRS (Supple-
mental Restraint System), are complemen-
tary, co-ordinated restraint systems
(Y
page 41). They reduce the risk of injury in
specific, pre-defined types of accident situa-
tions and thereby increase occupant safety.
However, seat belts and airbags generally do
not protect against objects penetrating the
vehicle from the outside.
To ensure that the restraint systems can
deliver their full potential protection, make
sure that:
R the seat and head restraint are adjusted
properly (Y page 92)
R the seat belt has been fastened properly
(Y page 46)
R the airbags can inflate unrestricted if
deployed (Y page 42)
R the steering wheel is adjusted properly
(Y page 98)
R the restraint systems have not been modi-
fied
An airbag increases the protection of vehicle
occupants wearing a seat belt. However, air-
bags are only an additional restraint system
which complements, but does not replace,
the seat belt. All vehicle occupants must wear their seat belt correctly at all times, even if thevehicle is equipped with airbags. The airbags
are not deployed in all types of accidents. For example, if the protective capacity of cor-
rectly fastened seat belts is not increased by
deploying the airbags, the airbags will not
deploy.
Airbag deployment only provides increased
protection if the seat belt is worn correctly.
The seat belt helps, firstly, to keep the vehicle
occupant in the best position in relation to the airbag. Secondly, in a head-on collision, for
example, the seat belt prevents the vehicle
occupant from being propelled towards the
point of impact. 40
Occupant safetySafety

deploy correctly and would fail to provide the
intended protection in the event of an acci-
dent. Appropriate seat covers can be
obtained, for example, from a Mercedes-Benz
Service Centre. Front sidebags
:and rear sidebags ;
deploy next to the outer seat cushions.
When deployed, the sidebags offer additional protection of the thorax for occupants on the
front seats as well as also of the pelvis for the
vehicle occupants on the side of the vehicle
on which the impact occurs. However, they
do not protect the:
R head
R neck
R arms
The sidebags are deployed:
R on the side on which an impact occurs
R at the start of an accident with a high rate of
lateral vehicle deceleration or acceleration,
e.g. in a side impact
R independently of the use of the seat belt
R independently of the front airbags
R independently of the belt tensioners
If the vehicle overturns, the sidebags are gen- erally not deployed. Sidebags are deployed if
the system detects high vehicle deceleration or acceleration in a lateral direction and
determines that sidebag deployment can
offer additional protection to that provided by
the seat belt. Windowbags
Windowbags
:enhance the level of protec-
tion for the head (but not chest or arms), of
the vehicle occupants on the side of the vehi- cle on which the impact occurs.
Windowbags :are integrated into the side
of the roof frame and deployed in the area
from the A-pillar to the C-pillar.
Windowbags are deployed:
R at the start of an accident with a high rate of
lateral vehicle deceleration or acceleration,
e.g. in a side impact
R on the side on which an impact occurs
R on the driver's and the front passenger's
side if the vehicle overturns and the system
determines that deployment can offer addi-
tional protection to that provided by the
seat belt
R independently of the use of the seat belt
R regardless of whether the front-passenger
seat is occupied
R independently of the front airbags PRE-SAFE
®
(anticipatory occupant
protection) G
WARNING
When adjusting the seat, make sure that
nobody can become trapped.
! Make sure that there are no objects in the
footwell or behind the seats when moving
the seat back. There is a risk that the seats and/or the objects could be damaged. Occupant safety
45Safety Z

the driver and the front passenger have fas-
tened their seat belts.
i For more information on the
7seat
belt warning lamp, see "Warning and indi-
cator lamps in the instrument cluster, seat
belt" (Y page 257).
Rear seat belt status indicator Example: rear seat belt status indicator
The rear-compartment seat belt status indi-
cator indicates the rear seat on which the belt
is fastened. In the example, the occupant on
the right rear seat, when viewed in the direc- tion of travel, is secured. The üsymbol in
the display indicates a fastened seat belt. If a seat belt is not fastened or if a seat is not
occupied, the ýsymbol is displayed.
The rear-compartment seat belt status indi-
cator appears in the multifunction display for
around 30 second s if:
R you drive of f and reach a speed of approx-
imately 10 km/h.
R the rear passengers fasten or unfasten
their seat belts while the vehicle is in
motion.
R someone gets in or out of the vehicle and
the vehicle drives off again.
You can also cancel the rear seat belt status
indicator immediately (Y page 229).
i The status indicator for the rear-compart-
ment seat belts is only available for certain
countries.
Belt tensioners, belt force limiters G
WARNING
If the seat belt tensioners have been trig-
gered, they provide no additional protection in the event of another accident. Therefore,
have belt tensioners which have been trig-
gered replaced at a qualified specialist work-
shop.
Comply with safety regulations when dispos-
ing of belt tensioners. Any Mercedes-Benz
Service Centre can provide details of these
regulations.
! If the front-passenger seat is not occu-
pied, do not engage the seat belt tongue in
the buckle on the front-passenger seat.
Otherwise, the belt tensioner could be trig- gered in the event of an accident.
The front seat belts and the outer seat belts in
the rear are equipped with belt tensioners
and belt force limiters.
The belt tensioners tighten the seat belts in an
accident, pulling them close against the body.
Belt tensioners do not correct incorrect seat
positions or incorrectly fastened seat belts.
Belt tensioners do not pull vehicle occupants
back towards the backrest.
The belt tensioners can only be activated
when:
R the ignition is switched on.
R the restraint systems are operational; see
"6 SRS warning lamp" (Y page 41).
R the belt tongue is engaged in the buckle on
each of the front seat belts.
The belt tensioners on the outside seats in the
rear compartment are triggered independ-
ently of the lock status of the seat belts.
The belt tensioners are triggered depending
on the type and severity of an accident:
R if, in the event of a head-on or rear-end col-
lision the vehicle decelerates or acceler-
ates rapidly in a longitudinal direction dur-
ing the initial stages of the impact
R if, in the event of a side impact, on the side
opposite the impact the vehicle deceler- Occupant safety
49Safety Z

Do not expose the child restraint system to
direct sunlight. Parts of the child restraint sys- tem could heat up and the child could burn
herself/himself on them.
If a child opens a door, the child or other per-
sons could be injured as a result. They could
get out and injure themselves or be injured by
a passing vehicle.
Observe the general notes on the HOLD func- tion, which can be found under the same key-word. G
WARNING
Unsecured or incorrectly positioned loads
increase the risk of injury for children and all
other occupants in the event of:
R an accident
R sudden braking
R a sudden change of direction
Do not transport heavy or hard objects in the
vehicle interior unless they are secured. You
will find further information under "Loading
guidelines" in the index.
If a child is travelling in your vehicle, secure
the child using a child restraint system which is appropriate to the size, age and weight of
the child. You should preferably fit the
restraint system to a suitable rear seat. Make
sure that the child is secured for the trip.
Mercedes-Benz recommends that you use
the listed child restraint systems
(Y page 58). You can obtain further infor-
mation about the correct child restraint sys-
tem from any Mercedes-Benz Service Centre.
i It is advisable to use Mercedes-Benz care
products to clean child restraint systems.
You can obtain information about this at
any Mercedes-Benz Service Centre. Child restraint system on the front-
passenger seat G
WARNING
If the front-passenger airbag is not disabled:
R a child secured in a child restraint system
on the front-passenger seat could be seri-
ously and even fatally injured by the front-
passenger airbag deploying. This is espe-
cially a risk if the child is in the immediate
vicinity of the front-passenger airbag when
it deploys.
R never secure a child on the front-passenger
seat in a rearward-facing child restraint sys- tem. Only secure a rearward-facing child
restraint system on a suitable rear seat.
R always move the front-passenger seat to
the rearmost position if you secure a child
in a forward-facing child restraint system
on the front-passenger seat.
The front-passenger airbag is not disabled:
R on vehicles without automatic child seat
recognition on the front-passenger seat
R in vehicles with automatic child seat rec-
ognition in the front-passenger seat, if no
special child restraint system with trans-
ponders for automatic child seat recogni-
tion in the front-passenger seat has been
fitted
R on vehicles with automatic child seat rec-
ognition on the front-passenger seat, if the
PASSENGER AIRBAG OFF indicator lamp
4 is not lit.
To make you aware of this danger, a corre-
sponding warning sticker has been affixed on
the dashboard and on both sides of the sun
visor on the front-passenger side.
Information about recommended child
restraint systems is available at any
Mercedes-Benz Service Centre. Children in the vehicle
51Safety Z

X
To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or X Lock and then unlock the vehicle using the
key. Replacing bulbs
Important safety notes
Xenon bulbs G
DANGER
Xenon bulbs are under high voltage. You can
get an electric shock if you remove the cover
of the xenon bulb and touch the electrical
contacts. There is a risk of fatal injury.
Never touch the parts or the electrical con-
tacts of the xenon bulb. Always have work on the xenon bulbs carried out at a qualified spe- cialist workshop.
If your vehicle is equipped with xenon bulbs,
you can recognise this by the following: the
cone of light from the xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be
observed, the lights must be switched on
before starting the engine.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly.
Other bulbs G
WARNING
Bulbs, lamps and plug connectors can
become very hot during use. When replacing a bulb, you could burn yourself on these com-
ponents. There is a risk of injury.
Allow these components to cool down before replacing the bulb.
There are bulbs other than the xenon bulbs
that you cannot replace. Replace only the bulbs listed (Y
page 112). Have the bulbs that
you cannot replace yourself replaced at a
qualified specialist workshop.
If you require assistance replacing bulbs, con-
sult a qualified specialist workshop.
Do not touch the glass tube of new bulbs with
your bare hands. Even minor contamination
can burn into the glass surface and reduce
the service life of the bulbs. Always use a lint- free cloth or only touch the base of the bulb
when fitting.
Only use bulbs of the correct type.
If the new bulb still does not light up, consult
a qualified specialist workshop.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure that these function correctly at all times.
Have the headlamp setting checked regularly. 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 112
Replacing bulbsLights and
windscreen wipers

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). Overview of climate control systems
Important safety notes
Observe the settings recommended on the
following pages. The windows could other-
wise mist up.
To prevent the windows from misting up:
R switch off climate control only briefly
R switch on air-recirculation mode only
briefly
R switch on the cooling with air dehumidifi-
cation function
R switch on the defrost windscreen function
briefly, if required
THERMATIC automatic climate control/
THERMOTRONIC automatic climate control
regulates the temperature and the humidity
of the vehicle interior and filters out undesir-
able substances from the air.
THERMATIC automatic climate control/
THERMOTRONIC automatic climate control is only operational when the engine is running.
Optimum operation is only achieved with the
side windows and panorama sliding sunroof
closed.
The residual heat function can only be acti-
vated or deactivated with the ignition
switched off (Y page 133).
i Ventilate the vehicle for a brief period
during warm weather, e.g. using the con-
venience opening feature (Y page 84). Thiswill speed up the cooling process and the
desired vehicle interior temperature will be
reached more quickly.
i The integrated filter can filter out most
particles of dust and completely filters out
pollen. A clogged filter reduces the amount
of air supplied to the vehicle interior. For
this reason, you should always observe the interval for replacing the filter, which is
specified in the Service Booklet. As it
depends on environmental conditions, e.g. heavy air pollution, the interval may be
shorter than stated in the Service Booklet.
i It is possible that the residual heat func-
tion may be activated automatically an hour
after the key has been removed in order to
dry the air-conditioning system. The vehicle is ventilated for 30 minutes. 122
Overview of climate control systemsClimate control

Problems with the engine
Problem
Possible causes/consequences and
M
MSolutions The engine does not
start. The HOLD function or DISTRONIC PLUS is activated.
X Deactivate the HOLD function (Y page 179) or DISTRONIC
PLUS (Y page 173).
X Try to start the engine again. The engine does not
start. The starter motor
can be heard. R
There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.
X Turn the key back to position 0in the ignition lock before
attempting to start the engine again.
X Try to start the engine again (Y page 143). Avoid excessively
long and frequent attempts to start the engine, as this will drain the battery.
If the engine does not start after several attempts:
X Consult a qualified specialist workshop. The engine does not
start. The starter motor
can be heard. The
reserve fuel warning
lamp is lit and the fuel
gauge display shows 0. The fuel tank is empty.
X Refuel the vehicle. The engine does not
start. You cannot hear
the starter motor. The on-board voltage is too low because the battery is too weak or
discharged.
X Jump-start the vehicle (Y page 308).
If the engine does not start despite attempts to jump-start it:
X Consult a qualified specialist workshop. The starter motor was exposed to a thermal load that was too high.
X Allow the starter motor to cool down for approximately two
minutes.
X Try to start the engine again.
If the engine still does not start:
X Consult a qualified specialist workshop, e.g. a Mercedes-Benz
Service Centre. Driving
149Driving and parking Z