2012 MERCEDES-BENZ A CLASS battery

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 suffer burn-like injuries. There is a risk
of injury.
Therefore, do not switch on the seat heating
repeatedly.
The three red indicator lamps in the button
indicate the heating level you have selected.
The system automatically switches down
from level 3 to level 2 after approximately
eight minutes.
The system automatically switches down
from
level 2 to level 1 after approximately ten
minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
X Make sure that the key is in position 1 or
2 in the ignition lock.
X To switch on: press button : repeatedly
until the desired heating level is set.
X To switch off: press button : repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off. Problems with the seat heating The seat heating has switched off prema-
turely

or cannot be switched on. The vehicle's
electrical system voltage is too low because
too many electrical consumers are switched
on.
X Switch off electrical consumers that you do
not

need, such as the rear window heating
or interior lighting. AMG Performance Seat
To adjust the contour of the seat and for
improved

lateral support, you can individually
adjust the front seats. Adjusting the seat cushion length
X
To extend the seat cushion: press but-
ton :.
X To retract the seat cushion: press but-
ton ;.
Adjusting the side bolsters of the seat
cushion X
To set the side bolsters of the seat
cushion narrower: press button =.
X To set the side bolsters of the seat
cushion wider: press button ?. Seats
97
Seats, steering wheel and mirrors Z

Exterior mirrors
Adjusting the exterior mirrors G
WARNING
The exterior mirrors reduce the size of the
image. Objects visible in the mirrors are
closer than they appear. You could misjudge
the distance from road users driving behind
you
when changing lanes, for instance. There
is a risk of an accident.
You should therefore always look over your
shoulder to determine the actual distance
from road users driving behind you. X
Make sure that the key is in position 1 or
2 in the ignition lock.
X Press button : for the left-hand exterior
mirror

or button ; for the right-hand exte-
rior mirror.
The indicator lamp in the corresponding
button lights up in red.
The indicator lamp goes out again after
some time. You can adjust the selected
mirror using adjustment button = as long
as the indicator lamp is lit.
X Press adjustment button = up, down, or
to the left or right until you have adjusted
the exterior mirror to the correct position.
You should have a good overview of traffic
conditions.
The convex exterior mirrors provide a larger
field of vision.
After the engine has been started, the exte-
rior mirrors are automatically heated if the
rear window heating is switched on and the outside temperature is low. Heating takes a
maximum of 10 minutes.
i
The exterior mirrors can also be heated
manually by switching on the rear window
heating.
Folding

the exterior mirrors in/out elec-
trically X
Make sure that the key is in position 1 or
2 in the ignition lock.
X Briefly press button :.
Both exterior mirrors fold in or out.
i Make sure that the exterior mirrors are
always folded out fully while driving. They
could otherwise vibrate.
i If you are driving faster than 47 km/h
(30

mph) you can no longer fold in the exte-
rior mirrors.
Setting the exterior mirrors If the battery has been disconnected or com-
pletely discharged, the exterior mirrors must
be reset. The exterior mirrors will otherwise
not fold in when you select the "Fold in mir-
rors when locking" function in the on-board
computer (Y page 225).
X
Make sure that the key is in position 1 in
the ignition lock.
X Briefly press button :. Mirrors
99
Seats, steering wheel and mirrors 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 instrument cluster goes out. The
_
indicator lamp in the multifunction display
remains lit.
X To deactivate: move the combination
switch back to its normal position.
The _ indicator lamp in the multifunc-
tion display goes out. Headlamps misted up on the inside
The headlamps may mist up on the inside if
there is high atmospheric humidity.
X Switch on the lights and drive off.
The level of moisture diminishes, depend-
ing on the length of the journey and the
weather conditions (humidity and temper-
ature).
If the level of moisture does not diminish:
X Have the headlamps checked at a qualified
specialist workshop. Interior lighting
Overview of interior lighting
Front overhead control panel
:
p To switch the left-hand front reading
lamp on/off
; c To switch the front interior lighting
on
= v To switch the rear interior lighting
on/off
? |
To switch the front interior lighting/
automatic interior lighting control off A
p
To switch the right-hand front read-
ing lamp on/off
B To switch the automatic interior lighting
control on Rear-compartment overhead control panel
:
p
To switch the left-hand reading lamp
on/off
; p To switch the right-hand reading
lamp on/off Interior lighting control
Important notes In order to prevent the vehicle's battery from
discharging,

the interior lighting functions are
automatically deactivated after some time
except for when the key is in position 2 in the
ignition lock.
The brightness of the ambient lighting may be
set using the on-board computer
(Y page 222).
Automatic interior lighting control X
To switch on: set the switch to centre
position B.
X To switch off: set the switch to the |
position.
The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the key from the ignition lock Interior lighting
111
Lights and windscreen wipers Z

Windows misted up on the outside
X
Activate the windscreen wipers.
X Set the air distribution to P or O.
i You should only select this setting until
the windscreen is clear again. Rear window heating
Switching on/off The rear window heating has a high current
draw. You should therefore switch it off as
soon as the window is clear. It otherwise
switches off automatically after several
minutes.
If
the battery voltage is too low, the rear win-
dow heating may switch off.
X Turn the key to position 2 in the ignition
lock (Y page 143).
X Press the ¤ button.
The

indicator lamp in the ¤ button lights
up or goes out. Operating the climate control system
131
Climate control

Problems with the rear window heating
Problem Possible causes/consequences and
M SolutionsThe rear window heat-
ing has switched off
prematurely or cannot
be activated. The battery has not been sufficiently charged.
X
Switch off any consumers that are not required, e.g. reading
lamps, interior lighting or the seat heating.
When
the battery is sufficiently charged, the rear window heat-
ing can be activated again. Activating/deactivating air-recircula-
tion mode
If you switch on air-recirculation mode, the
windows can mist up more quickly, in partic-
ular at low temperatures. Only use air-recir-
culation

mode briefly to prevent the windows
misting up.
You can deactivate the flow of fresh air if
unpleasant odours are entering the vehicle
from outside. The air already inside the vehi-
cle will then be recirculated.
The operation of air-recirculation mode is the
same for all control panels.
X Turn the key to position 2 in the ignition
lock (Y page 143).
X To activate: press the e button.
The
indicator lamp in the e button lights
up.
i Air-recirculation mode is activated auto-
matically at high outside temperatures.
When air-recirculation mode is activated
automatically, the indicator lamp in the
e button is not lit.
Outside air is added after about
30 minutes.
X To deactivate: press the e button.
The
indicator lamp in the e button goes
out. i
Air-recirculation mode deactivates auto-
matically:
R after approximately five minutes at out-
side temperatures below approximately
5 †.
R after approximately five minutes if the
"Cooling

with air dehumidification" func-
tion is deactivated.
R after approximately 30 minutes at out-
side temperatures above approximately
5 † and when the "Cooling with air dehu-
midification function" is activated. Convenience opening/closing using
the air-recirculation button
G
WARNING
When the convenience closing feature is oper-
ating,
parts of the body could become trapped
in the closing area of the side window and the
sliding sunroof. There is a risk of injury.
Observe the complete closing procedure
when the convenience closing feature is oper-
ating. When closing make sure that no parts
of the body are in the closing area. G
WARNING
During convenience opening parts of the body
could be drawn in or become trapped
between

the side window and window frame.
There is a risk of injury.
When opening, make sure that nobody is
touching the side window. If someone
becomes trapped, press the W switch132
Operating the climate control system
Climate control

immediately to open/close the side window
in the door. The side window stops. To con-
tinue closing the side window, pull on the
W switch.
X Convenience closing feature: press and
hold the e button until the side win-
dows
and the panorama sliding sunroof are
closed.
The indicator lamp in the e button lights
up. Air-recirculation mode is activated.
If parts of the body are in the closing area
during convenience closing, proceed as fol-
lows:
X To open/close the side window, press the
W button.
The side window stops.
X To then open the side window, press the
W button again.
X To open/close the panorama sliding sun-
roof press the 3 button.
The panorama sliding sunroof stops.
X To then open the panorama sliding sunroof
press the 3 button again.
X Press the d
button again for longer than
2 seconds.
The side windows move in the opposite
direction.
i Notes on the automatic reversing func-
tion for:
R the side window

(Y page 84)
R the panorama sliding sunroof
(Y page 87)
X Convenience opening feature:
press and
hold the e button until the side win-
dows and the panorama sliding sunroof
have opened. The side windows and the
panorama sliding sunroof move back to
their original position.
The indicator lamp in the e button goes
out. Air-recirculation mode is deactivated.
i If you open the side windows or the pan-
orama sliding sunroof manually after clos-
ing with the convenience closing feature, they will remain in this position when
opened

using the convenience opening fea-
ture. Activating/deactivating the residual
heat function
The residual heat function is only available
with

THERMOTRONIC automatic climate con-
trol.
It is possible to make use of the residual heat
of the engine to continue heating the vehicle
for approximately 30 minutes after the engine
has been switched off. The heating time
depends on the temperature that has been
set for the vehicle interior.
i The blower will run at a low speed regard-
less of the airflow setting.
i If you activate the residual heat function
at high temperatures, only the ventilation
will be activated. The blower runs at
medium speed.
X Turn the key to position 0 in the ignition
lock or remove it ( Y page 143).
X To activate: press the Ì button.
The
indicator lamp in the Ì button lights
up.
X To deactivate: press the Ì button.
The
indicator lamp in the Ì button goes
out.
i Residual heat is deactivated automati-
cally:
R after approximately

30 minutes
R when the ignition is switched on
R if the battery voltage drops
R when the auxiliary heating is switched on Operating the climate control system
133
Climate control Z