2012 MERCEDES-BENZ A CLASS window

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

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

Adjusting the side air vents
:
Side window demister vent
; Side air vent
X To open a side air vent: turn the adjuster
in side air vent ; anti-clockwise.
X To close a side air vent: turn the adjuster
in side air vent ; clockwise until it
engages. Setting the rear-compartment air
vents
:
Rear-compartment air vent, left
; Rear-compartment air vent, right
= Rear-compartment air vent thumbwheel
X To open/close: turn
thumbwheel = up or
down. 140
Adjusting the air vents
Climate control

Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt
residue may form on the brake discs and
brake pads. This can result in a significantly
longer braking distance.
R
Brake
occasionally to remove any possible
salt residue. Make sure that you do not
endanger other road users when doing so.
R Carefully depress the brake pedal and the
beginning and end of a journey.
R Maintain a greater distance to the vehicle
ahead.
New brake pads/linings New and replaced brake pads and discs only
reach

their optimum braking effect after sev-
eral hundred kilometres of driving. Compen-
sate for this by applying greater force to the
brake pedal.
For safety reasons, Mercedes-Benz recom-
mends that you only have brake pads/linings
fitted to your vehicle which have been
approved for Mercedes-Benz vehicles or
which correspond to an equivalent quality
standard. Brake pads/linings which have not
been approved for Mercedes-Benz vehicles or
which are not of an equivalent quality could
affect your vehicle's operating safety. Driving on wet roads
Aquaplaning If water has accumulated to a certain depth
on

the road surface, there is a danger of aqua-
planing occurring, even if:
R you are driving at low speeds
R the tyres have adequate tread depth
For this reason, do not drive in tyre ruts and
brake carefully. Driving on flooded roads !
Bear in mind that vehicles travelling in
front or in the opposite direction create
waves. This may cause the maximum per-
missible water depth to be exceeded.
These notes must be observed under all
circumstances. You could otherwise dam-
age

the engine, the electronics or the trans-
mission.
If you have to drive on stretches of road on
which water has collected, please bear in
mind that:
R the maximum permissible fording depth in
still water is 25 cm
R you should drive no faster than walking
pace Winter driving
General notes G
WARNING
If you shift down on a slippery road surface in
an attempt to increase the engine's braking
effect, the drive wheels could lose their grip.
This

increases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on a slippery road surface. G
DANGER
If the exhaust pipe is blocked or adequate
ventilation is not possible, poisonous gases
such

as carbon monoxide (CO) may enter the
vehicle. This is the case, e.g. if the vehicle
becomes trapped in snow. There is a risk of
fatal injury.
If you leave the engine or the auxiliary heating
running, make sure the exhaust pipe and area
around the vehicle are clear of snow. To
ensure an adequate supply of fresh air, open
a window on the side of the vehicle that is not
facing into the wind. Driving tips
167
Driving and parking Z