2012 MERCEDES-BENZ A-CLASS HATCHBACK engine

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 anenvironmentally 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.
The battery and the cover of the positive
terminal clamp must be fitted securely dur- ing operation. Battery (vehicle)
305Breakdown assistance Z

ing the vehicle or charging the battery, gases
can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
start connection point.
The jump-starting connection point is in the
engine compartment (Y page 308).
X Open the bonnet (Y page 285).
X Connect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure (Y page 308).
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case
you may neither jump-start the vehicle nor
charge the battery. The service life of a bat-
tery that has been thawed could be reduced. The starting characteristics may be impaired,
especially at low temperatures. Have the
thawed battery checked at a qualified spe-
cialist workshop.
Only charge the installed battery with a bat-
tery charger which has been tested and
approved by Mercedes-Benz. A battery
charger unit specially adapted for Mercedes- Benz vehicles and tested and approved by
Mercedes-Benz is available as an accessory.
It permits the charging of the battery in its
installed position. Contact a Mercedes-Benz
Service Centre for information and availabil-
ity. Read the battery charger's operating
instructions before charging the battery. Battery (vehicle)
307Breakdown assistance Z

Jump-starting
For the jump-starting procedure, use only the jump-starting connection point, consisting of a positive terminal and an earth point, in the engine compartment. 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. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces 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 contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described 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 disconnecting
the jump leads.
R Never connect or disconnect the battery terminals while the engine is running. G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting. G
WARNING
Non-combusted fuel can collect in the exhaust system and ignite. There is a risk of fire. Avoid
repeated and lengthy starting attempts.
! Vehicles with a petrol engine:
avoid repeated and lengthy starting attempts. Otherwise,
the non-combusted fuel may damage the catalytic converter.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the
discharged battery has frozen. In this case you may neither jump-start the vehicle nor charge
the battery. The service life of a battery that has been thawed could be reduced. The starting 308
Jump-startingBreakdown assistance

characteristics may be impaired, especially at low temperatures. Have the thawed battery
checked at a qualified specialist workshop.
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged, the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.
R Vehicles with a petrol engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed from batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R the jump leads are not damaged.
R bare parts of the terminal clamp do not come into contact with other metal parts while the
jump leads are connected to the battery.
R the jump leads cannot come into contact with parts which can move when the engine is
running, such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Manual transmission: shift into neutral.
X Automatic transmission: shift the transmission to position P.
X Turn the key to position 0in the ignition lock and remove it.
X Switch off all electrical consumers (e.g. radio, blower, etc.).
X Open the bonnet (Y page 285). Jump-starting
309Breakdown assistance Z

Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Press together cover :of positive clamp ;and slide it back.
X Connect positive terminal ;on your vehicle to positive terminal =of donor battery B
using the jump lead, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ?of donor battery Bto earth point Aof your vehicle using the
jump lead, connecting the jump lead to donor battery Bfirst.
X Start the engine.
X Before disconnecting the jump leads, let the engines run for several minutes.
X First, remove the jump leads from earth point Aand negative terminal ?, then from pos-
itive clamp ;and positive terminal =. Begin each time at the contacts on your own vehicle
first.
X Close cover :of positive clamp ;after removing the jump leads.
X Have the battery checked at a qualified specialist workshop.
i Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump starting can be obtained at
any qualified specialist workshop. Towing and tow-starting
Important safety notes
G
WARNING
Safety-relevant functions are restricted or not
available if:
R the engine is not running.
R the brake system or the power steering is
malfunctioning
R the voltage supply or the vehicle's electrical
system is malfunctioning.
If your vehicle is towed, significantly greater
force may be required to steer the vehicle or
to brake. There is a risk of an accident.
In such circumstances, use a towing bar.
Make sure that the steering is moving freely
before towing. G
WARNING
If the weight of the vehicle to be towed or tow- started is greater than the permissible gross
weight of your vehicle:
R the towing eye could detach itself
R the vehicle/trailer combination could over-
turn.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per-
missible gross weight of your vehicle.
Information on your vehicle's gross vehicle
weight rating can be found on the vehicle
identification plate (Y page 338). G
WARNING
The vehicle is braked when the HOLD function or DISTRONIC PLUS is activated. Therefore,
deactivate HOLD and DISTRONIC PLUS if the
vehicle is to be towed. 310
Towing and tow-startingBreakdown assistance

Vehicles with a TIREFIT kit: the towing eye
is located under the tyre inflation compres-
sor.
X Press the mark on cover :inwards in the
direction of the arrow.
X Remove cover :from the opening.
X Screw the towing eye in clockwise to the
stop and tighten it.
Vehicles with a trailer tow hitch do not have a bracket for the screw-in towing eye at the
back. If you intend to use the vehicle for tow- ing, fold out the ball coupling (Y page 203)
and secure the towbar to it.
Removing the towing eye X
Loosen the towing eye and unscrew it.
X Attach cover :to the bumper and press
until it engages.
X Place the towing eye in the stowage well
under the luggage compartment floor
(Y page 299).
X Vehicles with a TIREFIT kit: replace the tyre
inflation compressor. Towing the vehicle with the front axle
raised
Only vehicles without 4MATIC can be
towed with the front axle raised.
! Vehicles with 4MATIC must not be towed
with the front or rear axle raised; otherwise, the transmission may be damaged.
Vehicles with 4MATIC may either be towed
away with both axles on the ground or be loa-
ded up and transported.
! The ignition must be switched off if you
are towing the vehicle with the front axle
raised. Intervention by ESP ®
could other-
wise damage the brake system.
X Turn the key to position 2in the ignition
lock.
X When the vehicle is stationary, depress the
brake pedal and keep it depressed. X
Vehicles with manual transmission:
depress the clutch pedal fully and shift to
neutral.
or
X Vehicles with automatic transmission:
shift the automatic transmission to posi-
tion P.
X Release the brake pedal.
X Release the electric parking brake.
X Deactivate automatic locking (Y page 223).
X Switch on the hazard warning lamps
(Y page 108).
X Turn the key in the ignition lock to position
0 and leave the key in the ignition lock.
When towing your vehicle with the front axle
raised, it is important that you observe the
safety instructions (Y page 310). Towing the vehicle with both axles on
the ground G
WARNING
The power assistance for the steering and the brake force booster do not work when the
engine is not running. You will then need
much more effort to brake and steer the vehi-
cle. Adapt your style of driving accordingly.
i In order to signal a change of direction
when towing with the hazard warning lamps switched on, use the combination switch asusual. In this case, only the turn signals for
the desired direction flash. When you reset
the combination switch, the hazard warn-
ing lamps start flashing again. 312
Towing and tow-startingBreakdown assistance

Tow-starting (emergency engine
starting)
! Do not tow-start vehicles with automatic
transmission. You could otherwise damage the automatic transmission.
Before tow-starting, the following conditions
must be fulfilled:
R the battery is connected.
R the engine has cooled down.
R the exhaust system has cooled down.
X Switch on the hazard warning lamps
(Y page 108).
X Fit the towing eye (Y page 311).
X Secure the rigid towing bar or the towing
rope.
X Depress and hold the brake pedal.
X Turn the key to position 2in the ignition
lock.
X Depress the clutch pedal and keep it
depressed.
X Engage neutral.
X Release the brake pedal.
X Tow-start the vehicle.
X Engage second gear.
X Release the clutch pedal slowly without
depressing the accelerator pedal.
The engine is started.
X Depress the clutch pedal and shift to neu-
tral.
X Stop at a suitable place.
X Secure the vehicle by applying the electric
parking brake.
X Remove the rigid towing bar or towing rope.
X Remove the towing eye (Y page 312).
X Switch off the hazard warning lamps.
When tow-starting, it is important that you
observe the safety instructions (Y page 310)
and the legal requirements for the relevant
countries. Electrical fuses
Important safety notes
G
WARNING
If you manipulate, bridge or replace a faulty
fuse with a fuse of a higher amperage, the
electric cables could be overloaded. This may result in a fire. There is a risk of an accident
and injury.
Always replace faulty fuses with specified new fuses of the correct amperage.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system concerned. Only use fuses marked with an
"S". Components or systems could other-
wise be damaged.
The fuses in your vehicle serve to disconnect faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions will
fail.
Blown fuses must be replaced with fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the cause traced and rectified at a qualified spe-
cialist workshop, e.g. a Mercedes-Benz Ser-
vice Centre. Before replacing a fuse
X Secure the vehicle against rolling away
(Y page 162).
X Switch off all electrical consumers.
X Turn the key to position 0in the ignition
lock and remove it (Y page 143). All indi-
cator lamps in the instrument cluster must be off.
The fuses are located in various fuse boxes:
R fuse box in the engine compartment on the
left-hand side of the vehicle, when viewed
in the direction of travel
R fuse box in the front-passenger footwell 314
Electrical fusesBreakdown assistance

The fuse allocation chart is on the fuse box in
the front-passenger footwell (Y page 315).Fuse box in the engine compartment
G
WARNING
When the bonnet is open, and the windscreen wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses. X
Open the bonnet.
X Remove any existing moisture from the
fuse box using a dry cloth.
X To open: open clamps ;.
X Fold cover :up in the direction of the
arrow and remove it. X
To close: check whether the seal is lying
correctly in cover :.
X Insert cover :at the back into openings
= on the fuse box.
X Fold down cover :.
X Hook clamps ;into the fuse box and
close.
X Close the bonnet. Fuse box in the front-passenger foot-
well
X
To open: remove the floormat from the
front-passenger side.
X Fold out perforated floor covering :in the
direction of the arrow. Electrical fuses
315Breakdown assistance Z