lights MERCEDES-BENZ B-CLASS 2012 Service Manual

for the front-passenger side as well. The
indicator 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
residual heat function can only be activated
or deactivated with the ignition switched
off.
ECO start/stop function During automatic engine switch-off, the ECO
start/stop function only operates at a
reduced capacity. If you require the full
climate control
output,

you can switch off the
ECO start/stop function by pressing the ECO
button ( Y page 138). Operating the climate control
systems
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 fog up.
Therefore, switch off climate control only
briefly
Activating/deactivating
Automatic climate control
X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To switch on: turn control A
clockwise to
the desired position (except position 0)
(Y page 119).
X To switch off: turn control A counter-
clockwise to position 0(Y page 119). Dual-zone automatic climate control
X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
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 previously selected settings are
restored.
X To deactivate: press the ^ button.
The indicator lamp

in the ^ button lights
up.
i Dual-zone automatic climate control:
switch on climate control primarily using
the à button. Activating/deactivating cooling with
air dehumidification
Points to observe before use If you deactivate the "Cooling with air-
dehumidification" function, the air inside the
vehicle will not be cooled. The air inside the
vehicle will also not be dehumidified. The
windows can
fog

up more quickly. Therefore,
only deactivate the "Cooling with air-
dehumidification" function briefly.
The cooling with air dehumidification function
is only available when the engine is running.
The air inside the vehicle is cooled and
dehumidified according to the temperature
selected.
Condensation may drip from the underside of
the vehicle when it is in cooling mode. This is
normal and not a sign that there is a
malfunction. Operating the climate control systems
123
Climate control
ProCarManuals.com

Activating/deactivating
X
To activate: press the ¿ button.
The indicator lamp
in the ¿ button lights
up.
X To deactivate: press the ¿ button.
The indicator lamp

in the ¿ button goes
out. The "Cooling with air dehumidification"
function has a delayed switch-off feature. 124
Operating the climate control systems
Climate control
ProCarManuals.com

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
"Cooling with air
dehumidification"
function cannot be
switched on. Cooling with air dehumidification has been deactivated due to a
malfunction.
X
Visit a qualified specialist workshop. Setting the climate control to
automatic
The automatic function is only available in
conjunction with dual-zone
automatic climate
control.
In automatic mode, the set temperature is
maintained automatically at a constant level.
The system automatically regulates the
temperature 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 necessary, cooling
with air dehumidification can be deactivated.
If you deactivate the "Cooling with air-
dehumidification" function, the air inside the
vehicle will not be cooled. The air inside the
vehicle will also not be dehumidified. The
windows can fog up more quickly. Therefore,
only deactivate the "Cooling with air-
dehumidification" function briefly.
X Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
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 mode: 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
Automatic climate control You can set the temperature for the entire
vehicle.
X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To increase/reduce: turn control :
clockwise or counter-clockwise
(Y page 119).

Only change the temperature
setting in small increments. Start at 72 ‡
(22 †).
Dual-zone automatic climate control Different temperatures can be set for the
driver's and front-passenger sides.
X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To increase/reduce: turn control : or
E clockwise or counter-clockwise
(Y page
121).

Only change the temperature Operating the climate control systems
125
Climate control
ProCarManuals.com

setting in small increments. Start at 72 ‡
(22 †).
Setting the air distribution
Automatic climate control Air distribution settings
¯
Directs air through the defroster vents
P Directs air through the center and side
air vents
O Directs air through the footwell air
vents
i You can also activate several air
distribution settings simultaneously. To do
this, press multiple
air distribution buttons.
The air is then directed through various
vents.
Setting the air distribution
X Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X Press one or more of the P, O,
¯ buttons.
The corresponding indicator

lamp lights up
briefly.
Dual-zone automatic climate control Air distribution settings
¯
Directs air through the defroster vents
P Directs air through the center and side
air vents
O Directs air through the footwell air
vents
b Directs air through the defroster,
center and side air vents
a Directs air through the defroster and
footwell 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 SmartKey to position 2 in the
ignition lock (Y page 135).
X Press the É or Ë button repeatedly
until the desired symbol appears in the
display. Setting the airflow
Automatic climate control X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To increase/reduce: turn control A
clockwise or counter-clockwise
(Y page 119).
Dual-zone automatic climate control X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To increase/reduce: press the K or
I button. Switching the ZONE function on/off
This function is only available with dual-zone
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.
The temperature setting for the driver's
side is adopted for the front-passenger
side. 126
Operating the climate control systems
Climate control
ProCarManuals.com

Defrosting the windshield
You can use this function to defrost the
windshield or to defrost the inside of the
windshield and the side windows.
i You should only select the "windshield
defrosting" function until the windshield is
clear again.
X Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
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 windshield and
front side windows
R air-recirculation mode off
i The "windshield defrosting" function
automatically sets the

blower output to the
optimum defrosting effect. As a result, the
airflow may increase or decrease
automatically after the button is pressed.
i You can adjust the blower output
manually while the "Windshield defrosting"
function is in operation:
R Automatic climate control: turn airflow
control A clockwise or counter-
clockwise (Y page 119).
R Dual-zone automatic climate control:
press the ó or ô button.
X To deactivate: press the ¬ button.
The indicator lamp

in the ¬ button goes
out. The previously selected settings are
restored. Air-recirculation mode remains
deactivated.
or X
Press the à button. 5
The indicator
lamp

in the ¬ button goes
out. Airflow and air distribution are set to
automatic mode.
or
X Automatic climate control: turn
temperature control : clockwise or
counter-clockwise ( Y page 119).
Dual-zone automatic climate control:
turn temperature controls : or E
clockwise or counter-clockwise
(Y page 121). MAX COOL maximum cooling
The MAX COOL function is only available in
vehicles for the USA.
MAX COOL is only operational when the
engine is running.
X To activate: press the Ù button.
The indicator lamp in the button lights up.
X To deactivate: press the Ù button
again.
The indicator lamp

goes out. The previously
selected settings are restored.
When you activate MAX COOL, climate
control switches to the following functions:
R maximum cooling
R maximum airflow
R air-recirculation mode on Defrosting the windows
Windows fogged up on the inside Automatic climate control
X
Activate the ¿ "Cooling with air
dehumidification" function.
X If the windows continue to fog up, activate
the "windshield defrosting" function
(Y page 127).
5 3-zone automatic climate control only. Operating the climate control systems
127Climate control
ProCarManuals.com

i
You should only select this setting until
the windshield is clear again.
Dual-zone automatic climate control
X Activate the ¿ "Cooling with air
dehumidification" function.
X Activate automatic mode Ã.
X If the windows continue to fog up, activate
the "windshield defrosting" function
(Y page 127).
i You should only select this setting until
the windshield is clear again.
Windows fogged up on the outside X
Activate the windshield wipers.
X Set the air distribution to P or O.
i You should only select this setting until
the windshield is clear again. Rear window defroster
Activating/deactivating The rear window defroster has a high current
draw. You should therefore switch it off as
soon as the rear window is clear. Otherwise,
the rear window defroster switches off
automatically after several minutes.
If the battery voltage is too low, the rear
window defroster may switch off.
X
Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X Press the ¤ button.
The indicator lamp
in the ¤ button lights
up or goes out. 128
Operating the climate control systems
Climate control
ProCarManuals.com

Problems with the rear window defroster
Problem Possible causes/consequences and
M SolutionsThe rear window
defroster has
deactivated
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
defroster can be activated again. Activating/deactivating air-
recirculation mode
If you switch on air-recirculation mode, the
windows can fog up more quickly, in
particular at low temperatures. Only use air-
recirculation mode briefly to prevent the
windows from fogging up.
You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle
from outside. The air already inside the
vehicle will then be recirculated.
The operation of
air-recirculation mode is the
same for all control panels.
X Turn the SmartKey to position 2 in the
ignition lock (Y page 135).
X To activate: press the e button.
The indicator lamp

in the e button lights
up.
i Air-recirculation mode is activated
automatically 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
automatically:
R after approximately five minutes at
outside temperatures below
approximately 41 ‡ (5 †)
R after approximately five minutes if the
"Cooling with air dehumidification"
function is deactivated
R after approximately 30 minutes at
outside temperatures above
approximately

41 ‡(5 †) if the "Cooling
with air dehumidification" function is
activated Activating/deactivating the residual
heat function
The residual heat

function is only available in
vehicles for Canada with dual-zone automatic
climate control.
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.
i The blower will run at a low speed
regardless 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. Operating the climate control systems
129
Climate control
ProCarManuals.com

X
Turn the SmartKey to position 0 in the
ignition lock or remove it ( Y page 135).
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
automatically:
R after approximately 30 minutes
R when the ignition is switched on
R if the battery voltage drops
R when the auxiliary heating is activated Setting the air vents
Important safety notes
G
WARNING
Very hot or very cold air can flow from the air
vents. This could

result in burns or frostbite in
the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air
outlets. If necessary, redirect the airflow to
another area of the vehicle interior.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
R keep the air inlet between the windshield
and the hood free of blockages, such as ice,
snow or leaves.
R never cover the air vents or air intake grilles
in the vehicle interior.
i You can move the adjusters for the air
vents vertically or horizontally to set the
direction of the airflow.
i For optimal climate control in the vehicle,
open the air vents completely and set the
adjusters to the central position. Setting the center air vents
X
To open the center air vent: turn the
adjuster in one of center air vents :
counter-clockwise.
X To close the center air vent: turn the
adjuster in one of center air vents :
clockwise until it engages. Setting the side air vents
:
Side window defroster vent
; Side air vent
X To open a side air vent: turn the adjuster
in side air vent ; counter-clockwise.
X To close a side air vent: turn the
adjuster
in side air vent ; clockwise until it
engages. 130
Setting the air vents
Climate control
ProCarManuals.com

again as soon as the
¤ symbol
reappears in the multifunction display.
Deactivating/activating the ECO start/
stop function ECO button
X
To switch off: press button :.
Indicator lamp ; on button : and the
¤ symbol
in
the multifunction display go
out.
X To switch on: press button :.
Indicator lamp ; lights up.
If all conditions for automatic engine
switch-off ( Y page 137) are fulfilled, the
¤ symbol is

shown in the multifunction
display.
If not all conditions for automatic engine
switch-off ( Y page 137) are fulfilled the
¤ symbol is not shown in the
multifunction display. If this is the case, the
ECO start/stop function is not available.
i If indicator lamp ;

is off, the ECO start/
stop function has been deactivated
manually or as the result of a malfunction.
The engine will then not be switched off
automatically when the vehicle stops. 138
Driving
Driving and parking
ProCarManuals.com

engine is switched off. The sounds that can
be heard
while
this is occurring are normal.
Applying/releasing manually Applying
X
Push handle :.
When the electric parking brake is
engaged, the !

red indicator lamp lights
up in the instrument cluster.
i The electric parking brake can also be
applied when the SmartKey is removed.
Releasing
X Pull handle :.
The red ! indicator lamp in the
instrument cluster goes out.
i You can only release the electric parking
brake when the key is in position 1 or 2 in
the ignition lock.
Applying automatically The electric parking brake is applied
automatically:
R
if DISTRONIC PLUS brings the vehicle to a
standstill or
R if the HOLD

function is keeping the vehicle
stationary
In addition, at least one of the following
conditions must be fulfilled:
R the engine is switched off.
R the driver's door is open and the seat belt
is not fastened.
R there is a system malfunction.
R the power supply is insufficient.
R the vehicle is stationary for a lengthy
period.
The red ! indicator lamp in the instrument
cluster lights up.
i The electric parking brake is not
automatically engaged if the engine is
switched off by the ECO start/stop
function. Releasing automatically Your vehicle's electric parking brake is
automatically released if all of the following
conditions are met:
R
the engine is running.
R the transmission is in position D or R.
R the seat belt has been fastened.
R you depress the accelerator pedal.
If the transmission

is in position R, the tailgate
must be closed.
If your seat belt is not fastened, the following
conditions must be fulfilled to automatically
release the electric parking brake:
R the driver's door is closed.
R you have shifted out of transmission
position P or you have previously driven
faster than 2 mph (3 km/h).
Emergency braking The vehicle can also be braked during an
emergency by using the electric parking
brake.
X
While driving, push handle : of the
electric
parking brake ( Y page 150).
i The vehicle is braked for as long as
handle : of the electric parking brake is
pressed. The longer electric parking brake
handle : is depressed, the greater the
braking force.
During braking:
R a warning tone sounds
R the Release Park. Brake message
appears
R the red ! indicator lamp in the
instrument cluster flashes
When the vehicle has been braked to a
standstill, the electric parking brake is
engaged. Parking
151
Driving and parking Z
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