2012 MERCEDES-BENZ A CLASS clock

X
To open the cover: turn handle : anti-
clockwise and fold down cover ; and
remove it. X
Pull out release wheel =.
X Turn release wheel = anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator
lamp ? flashes. G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is a risk of an
accident.
Always

engage the ball coupling as described.
X Pull the ball coupling in the direction of the
arrow

until it engages in a vertical position.
Indicator lamp ? goes out. The power
socket folds down automatically.
The multifunction display shows the
Check trailer hitch lock display mes-
sage until the ball coupling is engaged.
X Remove the protective covering from the
ball coupling and store it in a safe place.
X Make sure that the ball of the ball coupling
is clean and that it is either greased or dry
(grease free), depending on the instruc-
tions for the trailer. Coupling up a trailer
X Make sure that the transmission is in posi-
tion P.
X Apply the electric parking brake.
X Position the trailer level behind the vehicle.
X Couple up the trailer.
X Establish the electric connection between
the vehicle and the trailer.
X Check that the trailer lighting system is
working.
A trailer that is connected is recognised
only when the electrical connection is
established

correctly and when the lighting
system is working properly. The function of
other systems, such as ESP ®
or PARK-
TRONIC also depends on this. Uncoupling a trailer
G
WARNING
If you uncouple a trailer with an engaged over-
run
brake, you could trap your hand between204
Towing a trailer
Driving and parking

the vehicle and the trailer drawbar. This poses
a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle
could be damaged by the rebound-
ing of the overrun brake.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable.
X Make sure that the transmission is in posi-
tion P.
X Apply the electric parking brake.
X Secure the trailer against rolling away.
X Remove the trailer cable and decouple the
trailer. Folding in the ball coupling
G
WARNING
If you release the ball coupling or it does not
engage
correctly when folding in, it will swing
out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstructed. Always make sure that
the ball coupling engages when folding in.
X Fold the ball coupling back in if you are not
using the trailer tow hitch.
X Place the protective covering on the ball
coupling.
The release wheel is located behind the left-
hand side trim panel in the boot. X
To open the cover: turn handle : anti-
clockwise and fold down cover ; and
remove it. X
Pull out release wheel =.
X Turn release wheel =
anti-clockwise as far
as it will go.
The ball coupling disengages and folds out
behind the rear bumper. Indicator
lamp ? flashes. Towing a trailer
205
Driving and parking Z

X
Press the ball coupling in the direction of
the arrow until it engages behind the
bumper.
Indicator lamp ? goes out and the mes-
sage in the multifunction display disap-
pears. Trailer power supply
! You can connect accessories with a
power rating of up to 240 W to the perma-
nent
power supply and with a power rating
of up to 180 W to the power supply that is
switched on via the ignition lock.
The trailer battery may not be charged from
the power supply.
X To switch the connected power supply
on or off: turn the key in the ignition lock
to position 2 or 0 respectively.
When it leaves the factory, your vehicle's
trailer socket is equipped with a permanent
power supply and a power supply that is
switched on via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin
10.
The trailer's permanent power supply is
switched

off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about instal-
ling the trailer electrics at a qualified special-
ist workshop. Bulb failure indicator for LED lamps
i If LED lamps are fitted in the trailer, an
error message may appear in the multi-
function

display even if there is no fault. The
reason for the error message could be that
the current has fallen below the minimum
of 50 mA. To ensure reliable operation of the bulb failure
indicator,

each LED chain in the trailer lighting
must be guaranteed a minimum current of
50 mA. Trailer with 7-pin connector
General notes Trailer with 7-pin connector: you can con-
nect

to the 13-pin socket on the ball coupling
using an adapter or, if necessary, an adapter
cable. Both can be obtained at a qualified
specialist workshop.
Fitting the adapter !
Make sure that there is sufficient cable
play so that the cable cannot become
detached when cornering.
! Remove the installed adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumper and the adapter cable. X
Open the socket cover.
X Insert the plug connector with lug : into
groove =

on the socket. Turn bayonet con-
nection ; clockwise to the stop.
X Let the cover engage.
X If you are using an adapter cable, secure
the cable to the trailer with cable ties.206
Towing a trailer
Driving and parking

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). Important safety notes
G
WARNING
Operating the integrated information systems
and
communications equipment in the vehicle
while driving will distract you from traffic con-
ditions. You could then lose control of the
vehicle. There is a risk of an accident.
Only operate these devices if road traffic con-
ditions permit. If you are unsure about the
surrounding conditions, pull over to a safe
location and make entries only while the vehi-
cle is stationary. G
WARNING
If the instrument cluster has failed or mal-
functioned, you may not recognise function
restrictions relevant to safety. The operating
safety

of your vehicle may be impaired. There
is a risk of an accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop immedi-
ately.
You must observe the legal requirements for
the country in which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the mul-
tifunction display. You should therefore make
sure your vehicle is operating safely at all times. Otherwise, a vehicle that is not oper-
ating safely may cause an accident.
For an overview, see the instrument panel
illustration (
Y page 30). Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle inte-
rior

can be adjusted using the brightness con-
trol knob.
The brightness control knob is on the bottom
left of the instrument cluster ( Y page 30).
X Turn the brightness control knob clockwise
or anti-clockwise.
If the light switch is set to Ã, T or
L, the brightness is dependant upon
the brightness of the ambient light.
i The
light sensor in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated. Coolant temperature gauge
The coolant temperature gauge is in the
instrument cluster on the right-hand side.
The

reading may rise up to 120 † below nor-
mal driving conditions if the coolant has been
filled correctly.
At high outside temperatures and when driv-
ing uphill, the coolant temperature may rise
to the end of the scale. Rev counter
! Do not drive in the overrevving range.
Doing so will damage the engine.
The

red band in the rev counter indicates the
engine's overrevving range. 208
Displays and operation
On-board computer and displays

to the engine or to the catalytic converter.
Have excess engine oil siphoned off.
Example: engine oil filler cap
X
Turn cap : anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark
on the oil dipstick, top up with 1.0 litre of
engine oil.
X Replace cap : on the filler neck and turn
clockwise.
Make
sure that the cap locks securely into
place.
X Check the oil level again with the oil dip-
stick ( Y page 287).
For further information on engine oil, see
(Y page 343). Checking and adding other service
products
Checking the coolant level G
WARNING
The engine cooling system is under pressure,
particularly if the engine is warm. You could
be scalded by hot coolant spraying out when
opening the cap. There is a danger of injury.
Allow the engine to cool before opening the
cap. Wear gloves and protective eyewear
when

opening. Slowly turn the cap half a turn
to allow pressure to escape.
! The coolant level must only be checked
and corrected when the engine has cooled
down (coolant temperature under 40 †). Checking the coolant level when the cool-
ant temperature is over 40 † can lead to
damage to the engine or engine cooling
system.
Example
X
Park the vehicle on a level surface.
Only check the coolant level if the vehicle
is on a level surface and the engine has
cooled down.
X Turn the key to position 2 in the ignition
lock (Y page 143).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
40 †.
X Turn the key to position 0 (Y page 143) in
the ignition lock.
X Slowly turn cap : half a turn anti-clock-
wise to allow excess pressure to escape.
X Turn cap : further anti-clockwise and
remove it.
If the coolant is at the level of marker bar
= in the filler neck when cold, there is
enough coolant in coolant expansion
tank ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.
X Replace cap :
and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 344). 288
Engine compartment
Maintenance and care

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). Where will I find...?
Warning triangle
Removing/replacing the warning trian-
gle X
To remove: open the tailgate.
X Swing the luggage compartment floor
upwards

(Y page 274).
X To loosen warning triangle :, push back
the retainers on the bracket.
X Remove warning triangle : from the
bracket.
X To replace:
place warning triangle : back
into the bracket and push down to secure. Setting up the warning triangle
X
Fold feet = down and out to the side.
X Fold side reflectors ; upwards to form a
triangle and lock them at the top using
press stud :. First-aid kit
X
Open the tailgate.
X To open the stowage compartment:
turn
rotary knob : anti-clockwise and fold
down cover ;. 298
Where will I find...?
Breakdown assistance

The battery and the cover of the positive
terminal
clamp must be fitted securely dur-
ing operation.
Comply with safety precautions and take pro-
tective measures when handling batteries. WARNING
Fire, naked flames and smoking
are prohibited when handling the
battery. Avoid creating sparks.
Battery acid is caustic. Avoid con-
tact

with the skin, eyes or clothing.
Wear suitable protective clothing,
in particular gloves, an apron and
a face mask.
Immediately rinse acid splashes
off with clean water. Consult a doc-
tor if necessary. Wear eye protection.
Keep children away.
Observe this Owner's Manual.
For safety reasons, Mercedes-Benz recom-
mends
that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event
of an accident.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop. You can also charge the battery with a
charger recommended by Mercedes-Benz.
For

more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
i When you park the vehicle, remove the
key if you do not require any electrical con-
sumers. The vehicle will then use very little
energy, thus conserving battery power.
i If the power supply has been interrupted,
e.g. if the battery was discharged, you will
have to:
R set the clock (audio system/COMAND
Online, see the separate operating
instructions).
R reset the function for folding the exterior
mirrors in/out automatically, by folding
the mirrors out once ( Y page 99). Charging the battery
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
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. 306
Battery (vehicle)
Breakdown 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 2 in 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 as
usual. 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-starting
Breakdown assistance