2008 MERCEDES-BENZ ML350 Page 49

207 Controls in detail
Climate control
The climate control is operational whenev-
er the engine is running. You can operate
the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 214).
Warning!G
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature).
This may cause burns or frostbite to unpro-
tected skin in the immediate area of the air
vents.
Always keep sufficient distance between un-
protected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 206) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.
Warning!G
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled interval. A clogged filter will
reduce the air volume to the interior and the
windows could fog up, impairing visibility
and endangering you and others. Have a
clogged filter replaced as soon as possible
at an authorized Mercedes-Benz Light Truck
Center.
Warning!G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iIf the vehicle interior is hot, ventilate the in-
terior before driving off, see “Summer opening
feature” (
page 237). The climate control will
then adjust the interior temperature to the set
value much faster.
Keep the air intake grille in front of the wind-
shield free of snow and debris.

208 Controls in detail
Climate control
Deactivating the climate control
system
Deactivating
Press button´ (page 206).
The indicator lamp on the button
comes on.Reactivating
Press buttonU (page 206).
Operating the climate control system
in automatic modeActivating
Press buttonU (page 206) while
the engine is running.
The indicator lamp on the button
comes on. The air volume and air distri-
bution are adjusted automatically.
Use temperature controls1 and7
(
page 206) to separately adjust the
air temperature on each side of the
passenger compartment.
The interior air temperature is adjusted
automatically.
Deactivating
Press button
orQ
(
page 206).
The indicator lamp on buttonU
goes out. The automatic operation of
air volume switches off. The selected
blower speed is shown in the air
volume displayb (
page 206).
Warning!G
When the climate control system is
switched off, the outside air supply and cir-
culation are also switched off. Only choose
this settings for a short time. Otherwise the
windows could fog up, impairing visibility
and endangering you and others.
iYou can also press button´
(
page 206) on the climate control panel.
If you press button| (
page 206) to
reactivate the climate control system, the
defrosting mode is activated.
iWhen operating the climate control system
in automatic mode, you will only rarely need to
adjust the temperature, air volume and air distri-
bution.
In automatic mode, cooling with dehumidify is
switched on. This function can be switched off if
necessary (
page 215).
iThe settings for the passenger side are also
used for the rear passenger compartment.

209 Controls in detail
Climate control
or
Press air distribution button5,9,
ora (
page 206).
The indicator lamp on buttonU
goes out. The automatic operation of
air distribution switches off.
Setting the temperature
Use temperature controls1 and7
(
page 206) to separately adjust the air
temperature on each side of the passenger
compartment. You should raise or lower
the temperature setting in small incre-
ments, preferably starting at 72°F (22°C).
The climate control will adjust to the set
temperature as fast as possible.Increasing
Turn temperature control1
and/or7 (
page 206) slightly clock-
wise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing
Turn temperature control1
and/or7 (
page 206) slightly coun-
terclockwise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Adjusting air distribution
Press air distribution button5,9, ora
(
page 206) to adjust the air distribution.
The following symbols are found on the
controls:
Press the desired air distribution
button5,9, ora (
page 206).
The indicator lamp on buttonU
goes out.
SymbolFunction
aDirects air through the center
and side air vents
ZDirects air to the windshield
and side air vents
YDirects air to the footwells and
side air vents

210 Controls in detail
Climate control
Adjusting air volume
Five blower speeds are available.
Press button
to decrease or
buttonQ to increase air volume
(
page 206) to the desired level.
The indicator lamp on buttonU
(
page 206) goes out. The automatic
operation of air volume switches off.
The selected blower speed is shown in
the air volume displayb
(
page 206).
Adjusting air volume for the center and
side air vents
Opening the center air vents
Turn thumbwheels5 and8
(
page 204) to the right.
The corresponding center air vents on
the left and right are open.Closing the center air vents
Turn thumbwheels5 and8
(
page 204) to the left.
The corresponding center air vents on
the left and right are closed.
Opening the side air vents
Turn thumbwheels3 andb
(
page 204) to the right.
The corresponding side air vents on the
left and right are open.
Closing the side air vents
Turn thumbwheels3 andb
(
page 204) to the left.
The corresponding side air vents on the
left and right are closed.
Front defroster
You can use this setting to defrost the
windshield, for example if it is iced up. You
can also use it to defog the windshield and
door windows.
Activating
Press button| (page 206).
The indicator lamp on the button
comes on.
iKeep this setting selected only until the
windshield or the door windows are clear again.

211 Controls in detail
Climate control
The climate control switches to the follow-
ing functions automatically:

most efficient blower speed and
heating power, depending on outside
temperature

air flows onto the windshield and the
front door windows (side air vents must
be open)

the air conditioning compressor
switches on at outside temperatures
above approximately 41°F (5°C) for
air-dryingAdjustments
You can adjust the air volume and the tem-
perature when the front defroster is
switched on. The air flow will remain on the
windshield and front door windows.
Press button
to decrease or
buttonQ to increase air volume
(
page 206) to the desired level.
The air volume decreases/increases to
the next lower/higher blower speed
and heating switches to the tempera-
ture that was set before the front de-
froster was switched on.
The indicator lamp on button|
goes out. The indicator lamp on
button9 comes on.
or
Turn temperature control1
and/or7 (
page 206) slightly in any
direction.
Heating switches to the temperature
that was set before the front defroster
was switched on.The indicator lamp on button|
goes out. The indicator lamp on
button9 comes on.
iThe air conditioning compressor remains on
even if the indicator lamp in button| goes
out. This helps to prevent the windshield from
fogging.

212 Controls in detail
Climate control
Deactivating
Press button| (page 206) once
more.
The indicator lamp on the button goes
out. Defrosting is turned off.
The previous settings are in effect
again. The air conditioning compressor
remains switched on.
Windshield fogged on the outside
Switch the windshield wipers on
(
page 61).
Press button| (page 206).
The indicator lamp on the button
comes on.The climate control switches automatically
to the following functions:

most efficient blower speed and
heating power, depending on outside
temperature

air flows onto the windshield and the
front door windows (side air vents must
be open)

the air conditioning compressor
switches on at outside temperatures
above approximately 41°F (5°C) for
air-drying
If the automatic air distribution is switched
off:
Press air distribution button9 ora
(
page 206).
Air recirculation mode
Switch to air recirculation mode to prevent
unpleasant odors from entering the vehicle
from the outside (e.g. before driving
through a tunnel). This setting cuts off the
intake of outside air and recirculates the
air in the passenger compartment.
iTo switch off, you can also press
button´ orU (
page 206).
iKeep this setting selected only until the
windshield is clear again.
Warning!G
Fogged windows impair visibility,
endangering you and others. If the windows
begin to fog on the inside, switching off the
air recirculation mode immediately should
clear interior window fogging. If interior win-
dow fogging persists, make sure the air
conditioning (
page 206) is activated, or
press button|.

213 Controls in detail
Climate control
Activating
Press button: (page 206).
The indicator lamp on the button
comes on.DeactivatingPress button:.
The indicator lamp on the button goes
out.Air recirculation mode with conve-
nience closing and opening feature
iThe air recirculation mode is activated auto-
matically at high outside temperatures.
The indicator lamp on button: is not lit when
the air recirculation mode is switched on auto-
matically.
A quantity outside air is added after
approximately 30 minutes.
If you have turned off the air conditioning
(
page 214) or the outside temperature is
below 41°F (5°C), the air recirculation mode will
not switch on automatically.
iTo cool the interior as fast as possible, the
climate control automatically switches to air
recirculation. The indicator lamp on button:
is not lit when the air recirculation mode has
been switched on automatically.
iThe air recirculation mode is deactivated
automatically

after 5 minutes if the outside temperature is
below approximately 41°F (5°C)

after 5 minutes if the air conditioning and
air-drying is turned off

after 30 minutes if the outside temperature
is above approximately 41°F (5°C)
Warning!G
Never operate the windows and tilt/sliding
sunroof if there is the possibility of anyone
being harmed by the opening or closing pro-
cedure.
When using the air recirculation mode with
convenience closing feature, should the up-
ward movement of a window be blocked by
some obstruction including but not limited
to arms, hands, fingers, etc., the automatic
reversal feature will not operate.
In case the procedure causes potential
danger:
Vehicles with or without tilt/sliding sunroof:
The closing of the windows can be immedi-
ately halted by pressing or pulling the re-
spective window switch. The closing of the
tilt/sliding sunroof can be immediately halt-
ed by moving the switch for the tilt/sliding
sunroof in any direction.


215 Controls in detail
Climate control
Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the climate
control system. The air in the vehicle will
then no longer be cooled or dehumidified.
Press button9 (page 206).
The indicator lamp on the button goes
out.
Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Press button9 (page 206) again.
The indicator lamp on the button
comes on.
The air conditioning uses the refrigerant
R134a. This refrigerant is free of CFCs
which are harmful to the ozone layer.
Residual heat and ventilation
With the engine switched off, it is possible
to continue to heat or ventilate the interior
for up to 30 minutes. This feature makes
use of the residual heat produced by the
engine.Activating
Switch off the ignition (page 40).
Press button9 (page 206).
The indicator lamp on the button
comes on.
Deactivating
Press button9 (page 206).
The indicator lamp on the button goes
out.
!If the air conditioning cannot be turned on
again, this indicates that the air conditioning is
losing refrigerant. The compressor has turned
off.
Have the air conditioning checked at the nearest
authorized Mercedes-Benz Light Truck Center.
iHow long the system will provide heating
depends on

the coolant temperature

the battery voltage
Regardless of the temperature and air volume
set on the climate control panel, the interior tem-
perature is set to 72°F (22°C) and the blower
runs on low speed to protect the vehicle battery.
iThe residual heat is automatically turned off:

when the ignition is switched on

after about 30 minutes

if the coolant temperature is too low

if the battery voltage drops