ignition MERCEDES-BENZ A-CLASS HATCHBACK 2012 Service Manual

Problems with the "Cooling with air dehumidification" function
Problem
Possible causes/consequences and
M
MSolutions The 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 2in the ignition
lock (Y page 143).
X Set the desired temperature.
X To activate: press theÃbutton.
The indicator lamp in the Ãbutton lights
up. Automatic air distribution and airflow
are activated. X
To switch to manual operation: press the
É orË button.
or
X Press the KorI button.
The indicator lamp in the Ãbutton 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 2in 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 2in 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 systemClimate 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 2in 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 2in the ignition
lock (Y page 143).
X Press the ÉorË button until the
desired symbol appears in the display. Setting the airflow
THERMATIC automatic climate control X
Turn the key to position 2in the ignition
lock (Y page 143).
X To increase/reduce: turn controlA
clockwise or anti-clockwise (Y page 123).
THERMOTRONIC automatic climate
control X
Turn the key to position 2in the ignition
lock (Y page 143).
X To increase/reduce: press theKor
I button. Switching the ZONE function on/off
This function is only available with the
THERMOTRONIC automatic climate control.
X To activate: press theábutton.
The indicator lamp in the ábutton lights
up.
The temperature setting for the driver's
side is not adopted for the front-passenger
side.
X To deactivate: press theábutton.
The indicator lamp in the ábutton goes
out.
10 Only for certain countries. Operating the climate control system
129Climate 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 2in 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 Aclock-
wise or anti-clockwise (Y page 123).
R THERMOTRONIC automatic climate
control: press the óorô 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 Ãbutton 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 systemClimate control

Windows misted up on the outside
X
Activate the windscreen wipers.
X Set the air distribution to PorO.
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 2in 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
131Climate control

Problems with the rear window heating
Problem
Possible causes/consequences and
M
MSolutions The 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 thesame for all control panels.
X Turn the key to position 2in the ignition
lock (Y page 143).
X To activate: press theebutton.
The indicator lamp in the ebutton 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 theebutton.
The indicator lamp in the ebutton 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 †a nd 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 Wswitch 132
Operating the climate control systemClimate 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 ebutton until the side win-
dows and the panorama sliding sunroof are closed.
The indicator lamp in the ebutton 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 3button.
The panorama sliding sunroof stops.
X To then open the panorama sliding sunroof
press the 3button again.
X Press the dbutton 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 83)
R the panorama sliding sunroof
(Y page 87)
X Convenience opening feature: press and
hold the ebutton 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 ebutton 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 0in the ignition
lock or remove it (Y page 143).
X To activate: press theÌbutton.
The indicator lamp in the Ìbutton lights
up.
X To deactivate: press theÌbutton.
The indicator lamp in the Ìbutton 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
133Climate 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 2in 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 cont
rol

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 Ôof 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/ hfor
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
DrivingDriving 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. How- ever, 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
143Driving and parking Z

Manual transmission
X
Depress the brake pedal and keep it
depressed.
X Depress the clutch pedal fully.
X Shift to neutral N.
i You can only start the engine when the
clutch pedal is fully depressed.
Automatic transmission X
Shift the transmission to position P.
Transmission position display Pis shown in
the multifunction display.
i When the transmission is in position
N,
you can also start the engine with the brake pedal depressed.
Starting procedure X
To start a petrol engine: turn the key to
position 3in the ignition lock (Y page 143)
and release it as soon as the engine is run-
ning.
X To start a diesel engine: turn the key to
position 2in the ignition lock (Y page 143).
The % preglow indicator lamp in the
instrument cluster lights up.
X When the %preglow indicator lamp
goes out, turn the key to position
3(Y page 143) and release it as soon as the
engine is running.
i You can start the engine without preglow
if the engine is warm. Pulling away
Manual transmission !
Change gear in good time and avoid spin-
ning the wheels. Otherwise, you could dam- age the vehicle.
X Depress the brake pedal and keep it
depressed.
X Depress the clutch pedal fully. X
Shift to either first gear or reverse gear R.
X Release the electric parking brake
(Y page 163).
X Release the brake pedal.
X Slowly release the clutch pedal and gently
depress the accelerator pedal.
i Follow the shift recommendations in the
multifunction display for an economical
driving style (Y page 151).
i The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down.
You can open the doors from the inside at
any time.
You can also deactivate the automatic lock- ing feature (Y page 223).
Automatic transmission i
It is only possible to shift the transmission
from position Pto the desired position if
you depress the brake pedal. Only then can
the parking lock be deactivated. If you do
not depress the brake pedal, the DIRECT
SELECT lever can still be moved but the
parking lock remains engaged.
i At transmission fluid temperatures below
Ò20 †, you can only shift out of position P
into another transmission position when
the engine is running.
X Depress the brake pedal and keep it
depressed.
X Shift the transmission to position Dor R.
X Release the brake pedal.
X Carefully depress the accelerator pedal.
The electric parking brake (Y page 163) is
automatically released.
The red !indicator lamp in the instru-
ment cluster goes out.
i The vehicle locks centrally once you have
pulled away. The locking knobs in the doors
drop down. 144
DrivingDriving and parking