ignition MERCEDES-BENZ A CLASS 2012 Service Manual

erwise mist up as no fresh air is drawn into
the vehicle in air-recirculation mode.
R Use the ZONE function to adopt the tem-
perature settings on the driver's side for
the front-passenger side as well. The indi-
cator lamp in the á button goes out.
R Use the residual heat function if you want
to heat or ventilate the vehicle interior
when
the ignition is switched off. The resid-
ual heat function can only be activated or
deactivated with the ignition switched off.
ECO start/stop function During automatic engine switch-off, the cli-
mate

control only operates at a reduced capa-
city. If you require the full climate control out-
put, you can switch off the ECO start/stop
function by pressing the ECO button
(Y page 147). Operating the climate control system
Switching climate control on/off
Points to observe before use When the climate control is switched off, the
air supply and air circulation are also
switched off. The windows could then mist
up.

Therefore, switch off climate control only
briefly.
THERMATIC automatic climate control X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To switch on: turn
control A clockwise to
the desired position (except position 0)
(Y page 123).
X To switch off: turn control A anti-clock-
wise to position 0(Y page 123). THERMOTRONIC automatic climate
control X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To activate: press the à button.
The
indicator lamp in the à button lights
up. Airflow and air distribution are set to
automatic mode.
or
X Press the ^ button.
The

indicator lamp in the ^ button goes
out. The previous settings are reactivated.
X To deactivate: press the ^ button.
The
indicator lamp in the ^ button lights
up.
i THERMOTRONIC automatic climate con-
trol: switch on climate control primarily
using the à button. Activating/deactivating the cooling
with air dehumidification function
Points to observe before use If you deactivate the "Cooling with air dehu-
midification

function", the air inside the vehi-
cle will not be cooled in warmer weather. The
air inside the vehicle will not be dehumidified
either. The windows can mist up more
quickly. Therefore, only switch off the "Cool-
ing with air dehumidification function" briefly.
The "Cooling with air dehumidification" func-
tion is only available when the engine is run-
ning. The air inside the vehicle is cooled and
dehumidified according to the temperature
selected.
Condensation may drip from the underside of
the vehicle when cooling mode is active. This
is normal and not a sign that there is a mal-
function. 126
Operating the climate control system
Climate control

Problems with the "Cooling with air dehumidification" function
Problem Possible causes/consequences and
M SolutionsThe indicator lamp in
the ¿ button
flashes three times or
remains off. The "Cool-
ing with air dehumidifi-
cation
function" cannot
be switched on. Cooling with air dehumidification has been deactivated due to a
malfunction.
X
Visit a qualified specialist workshop. Setting climate control to automatic
mode
Only

THERMOTRONIC automatic climate con-
trol features the "control climate control
automatically" function.
In automatic mode, the set temperature is
maintained automatically at a constant level.
The system automatically regulates the tem-
perature of the dispensed air, the airflow and
the air distribution.
The automatic mode functions optimally
when the "Cooling with air dehumidification"
function is activated. If desired, cooling with
air dehumidification can be deactivated.
If you deactivate the "Cooling with air dehu-
midification function", the air inside the vehi-
cle will not be cooled in warmer weather. The
air inside the vehicle will not be dehumidified
either. The windows can mist up more
quickly. Therefore, only switch off the "Cool-
ing with air-dehumidification function" briefly.
X Turn the key to position 2 in the ignition
lock (Y page 143).
X Set the desired temperature.
X To activate: press the à button.
The
indicator lamp in the à button lights
up. Automatic air distribution and airflow
are activated. X
To switch to manual operation:
press the
É or Ë button.
or
X Press the K or I button.
The
indicator lamp in the à button goes
out. Automatic air distribution and airflow
are deactivated. Setting the temperature
THERMATIC automatic climate control You can set the temperature for the entire
vehicle.
X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To increase/reduce: turn control :
clockwise or anti-clockwise (Y page 123).
Only change the temperature setting in
small increments. Start at

22 †.
THERMOTRONIC automatic climate
control Different temperatures can be set for the
driver's and front-passenger sides.
X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To increase/reduce: turn controls : or
E clockwise or anti-clockwise
(Y

page 125). Only change the temperature
setting in small increments. Start at 22 †. 128
Operating the climate control system
Climate control

Setting the air distribution
THERMATIC automatic climate control Air distribution settings
¯
Directs the airflow through the demis-
ter vents
P Directs the airflow through the centre
and side air vents
O Directs the airflow through the foot-
well air vents
i You can also activate several of the air
distribution settings simultaneously. In
order to do this, press several of the air
distribution buttons. The air is then routed
through different air vents.
Setting the air distribution
X Turn the key to position 2 in the ignition
lock (Y page 143).
X Press one or more of the P, O,
¯ buttons.
The corresponding indicator lamp comes
on.
THERMOTRONIC automatic climate
control Air distribution settings
¯
Directs the airflow through the demis-
ter vents
P Directs the airflow through the centre
and side air vents
O Directs the airflow through the foot-
well air vents
S Directs airflow through the centre and
side
air vents as well as the footwell air
vents 10
.
b Directs the airflow through the centre
and

side air vents as well as the demis-
ter vents 10
a Directs the airflow through the foot-
well and demister vents i
Regardless of the air distribution setting,
airflow is always directed through the side
air vents. The side air vents can only be
closed

if the adjusters are turned clockwise
until they engage.
Setting the air distribution
X Turn the key to position 2 in the ignition
lock (Y page 143).
X Press the É or Ë button until the
desired symbol appears in the display. Setting the airflow
THERMATIC automatic climate control X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To increase/reduce: turn control A
clockwise or anti-clockwise (Y page 123).
THERMOTRONIC automatic climate
control X
Turn the key to position 2 in the ignition
lock (Y page 143).
X To increase/reduce: press the K or
I button. Switching the ZONE function on/off
This function is only available with the
THERMOTRONIC automatic climate control.
X To activate: press the á button.
The
indicator lamp in the á button lights
up.
The temperature setting for the driver's
side is not adopted for the front-passenger
side.
X To deactivate: press the á button.
The
indicator lamp in the á button goes
out.
10 Only for certain countries. Operating the climate control system
129
Climate control

The temperature setting for the driver's
side is adopted for the front-passenger
side.
Demisting the windscreen
You can use this function to defrost the wind-
screen or to demist the inside of the wind-
screen and the side windows.
i You should only select the "Windscreen
demisting" function until the windscreen is
clear again.
X Turn the key to position 2 in the ignition
lock (Y page 143).
X To activate: press the ¬ button.
The
indicator lamp in the ¬ button lights
up.
The climate control system switches to the
following functions:
R high airflow
R high temperature
R air distribution to the windscreen and
front side windows
R air-recirculation mode off
i The "Windscreen demisting" function
automatically

sets the blower output to the
optimum demisting effect. As a result, the
airflow may increase or decrease automat-
ically after the button is pressed.
i You can adjust the blower output man-
ually while the "Windscreen demisting"
function is in operation:
R THERMATIC automatic climate con-
trol: turn temperature control A clock-
wise or anti-clockwise ( Y page 123).
R THERMOTRONIC automatic climate
control: press the ó or ô button.
X To deactivate: press the ¬ button.
The
indicator lamp in the ¬ button goes
out. The previous settings are reactivated. Air-recirculation mode remains deactiva-
ted.
or
X Press the à button 11
.
The
indicator lamp in the ¬ button goes
out. Airflow and air distribution are set to
automatic mode.
or
X THERMATIC automatic climate control:
turn temperature control : clockwise or
anti-clockwise (Y page 123).
THERMOTRONIC automatic climate
control: turn temperature controls : or
E clockwise or anti-clockwise
(Y page 125). Demisting the windows
Windows misted up on the inside THERMATIC automatic climate control
X
Activate the ¿ "Cooling with air dehu-
midification" function.
X If the windows continue to mist up, activate
the "Windscreen demisting" function
(Y page 130).
i You should only select this setting until
the windscreen is clear again.
THERMOTRONIC automatic climate con-
trol
X Activate the ¿ "Cooling with air dehu-
midification" function.
X Activate automatic mode Ã.
X If the windows continue to mist up, activate
the "Windscreen demisting" function
(Y page 130).
i You should only select this setting until
the windscreen is clear again.
11 THERMOTRONIC only.130
Operating the climate control system
Climate control

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

Auxiliary heating
Important safety notes G
DANGER
If the exhaust pipe is blocked or sufficient
ventilation is not possible, toxic exhaust
fumes can enter the vehicle, especially car-
bon monoxide. This is the case, e.g. in
enclosed spaces, or if the vehicle is stuck in
snow. There is a risk of fatal injuries.
You should switch off the auxiliary heating in
enclosed
spaces which do not have an extrac-
tion system, e.g. a garage. If the vehicle is
stuck in snow and you must leave the auxiliary
heating running, keep the exhaust pipe and
the area around the vehicle clear of snow. To
guarantee a sufficient supply of fresh air, open
a window on the side of the vehicle away from
the wind. G
WARNING
When the auxiliary heating is switched on,
parts of the vehicle can become very hot.
Flammable material such as leaves, grass or
twigs

may ignite if they come into contact with
hot parts of the exhaust system for extended
periods. There is a risk of fire.
When the auxiliary heating is switched on,
make sure that no flammable material can
come into contact with hot vehicle compo-
nents.
! Operating the auxiliary heating/ventila-
tion draws on the vehicle battery. After you
have heated or ventilated the vehicle a
maximum of two times, drive for a longer
distance.
i Switch the auxiliary heating on regularly
once a month for about ten minutes.
The auxiliary heating heats the air in the vehi-
cle interior to the set temperature. This
occurs without using the heat of the running
engine. The auxiliary heating is operated
directly using the vehicle's fuel. For this rea-
son, the fuel tank must be at least ¼ full to
ensure that the auxiliary heating functions. The auxiliary heating/ventilation automati-
cally adjusts to changes in temperature and
weather

conditions. For this reason, the aux-
iliary heating could switch from ventilation
mode to heating mode or from heating mode
to ventilation mode.
The auxiliary heating switches off when the
engine is switched off. The auxiliary ventila-
tion switches off when you turn the key to key
position 2(Y page 143).
The auxiliary heating switches off automati-
cally after 30 minutes.
You cannot use the auxiliary ventilation to
cool the vehicle interior to a temperature
lower than the outside temperature.
Before switching on X
Turn the key to position 2 in the ignition
lock (Y page 143).
X Set the desired temperature.
Auxiliary heating or ventilation can also be
switched on if the manually set climate con-
trol is activated. Optimum comfort can be
attained

when the system is set to automatic
mode. Set the temperature to 22 †.
The auxiliary heating/ventilation can be acti-
vated or deactivated using the remote control
or the button on the centre console.
The on-board computer can be used to spec-
ify up to three departure times, one of which
may be preselected ( Y page 224).134
Operating the climate control systemClimate control

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). Running-in notes
Important safety notes
New brake pads/linings and discs that have
been

replaced only achieve optimum braking
effect after several hundred kilometres of
driving. Compensate for the reduced braking
effect by applying greater force to the brake
pedal. The first 1500 km
If you treat the engine with sufficient care
from

the very start, you will be rewarded with
excellent performance for the remainder of
the engine's life.
R Drive at varying vehicle speeds and engine
speeds for the first 1500 km.
R Avoid overstraining the vehicle during this
period, e.g. driving at full throttle.
R Change gear in good time, before the rev
counter needle is Ô of the way to the red
area of the rev counter.
R Do not shift down a gear manually in order
to brake.
Vehicles with automatic transmission:
R Try to avoid depressing the accelerator
pedal beyond the point of resistance (kick-
down).
After 1,500 km, you may gradually bring the
vehicle up to full road and engine speeds. Additional running-in notes for AMG vehicles:
R
Do

not drive at speeds above 140 km/h for
the first 1,500 km.
R Only allow the engine to reach a maximum
engine speed of 4,500 rpm briefly.
i You should also observe these notes on
running-in if the engine or parts of the drive
train on your vehicle have been replaced. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell may restrict
the clearance around the pedals or block a
depressed pedal. This jeopardises the oper-
ating and road safety of the vehicle. There is
a risk of an accident.
Stow

all objects securely in the vehicle so that
they do not get into the driver's footwell.
Always fit the floormats securely and as pre-
scribed in order to ensure that there is always
sufficient room for the pedals. Do not use
loose floormats and do not place several floor-
mats on top of one another. G
WARNING
Unsuitable footwear can hinder correct usage
of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. 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 142
Driving
Driving and parking

more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving.
G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only set the automatic transmission to the
respective drive positions when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. Otherwise, you could damage the
drive train.
! AMG vehicles: avoid full-load operation
and engine speeds greater than 5000 rpm
when the engine is cold. This helps to pro-
tect the engine and avoids uncomfortable
driving. Key positions
g
To remove the key
1 Power supply for some consumers, such
as the windscreen wipers 2
Ignition (power supply for all consumers)
and drive position
3 To start the engine
Vehicles with manual transmission: the
steering is locked when the key is taken out
of the ignition lock.
i If the key does not belong to the vehicle,
it can still be turned in the ignition lock.
However, the ignition will not be switched
on. The engine cannot be started. Starting the engine
Important safety notes G
WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these

exhaust gases leads to poisoning. There
is a risk of fatal injury. Therefore never leave
the engine running in enclosed spaces with-
out sufficient ventilation. G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite

if in contact with the exhaust system or
parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
! Do not depress the accelerator pedal
when starting the engine.
i Vehicles with a petrol engine: the
engine runs at a higher engine speed during
the cold start procedure so that the cata-
lytic converter can reach operating tem-
perature more quickly. The sound of the
engine may change as a result. Driving
143
Driving and parking Z