2008 MERCEDES-BENZ R320 air conditioning

226 Controls in detail
3-zone automatic climate control*
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 234).Deactivating the automatic climate
control system
Deactivating
Press button´ (page 224) until
the displaye (
page 224) is cleared.
The indicator lamp on the button
comes on.Reactivating
Press buttonU (page 224).
Warning!G
Follow the recommended settings for heat-
ing and cooling given on the following
pages. 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 244). The automatic 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.
Warning!G
When the automatic climate control system
is switched off, the outside air supply and
circulation are also switched off. Only
choose this setting for a short time.
Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iYou can also press button´
(
page 224) on the automatic climate control
panel.
If you press button| (
page 224) to reacti-
vate the automatic climate control system, the
defrosting mode is activated.

229 Controls in detail
3-zone automatic climate control*
Adjusting air volume
Five blower speeds are available.
Press button
to decrease or
buttonQ to increase air volume
(
page 224) to the desired level.
The indicator lamp on buttonU
goes out.
The automatic mode is switched off.
The selected blower speed appears in
the displaye (
page 224).
Front defroster
You can use this setting to defrost the
windshield, such as when it is iced up. You
can also use it to defog the windshield and
door windows.
Activating
Press button| (page 224).
The indicator lamp on the button
comes on.The automatic climate control switches to
the following 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-drying
Adjustments
You can adjust the air volume and the
temperature when the front defroster is
switched on. The air flow will remain on the
windshield and front door windows.
iKeep this setting selected only until the
windshield or the door windows are clear again.

230 Controls in detail
3-zone automatic climate control*
Press button
to decrease or
buttonQ to increase the air volume
(
page 224) 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
control1and/or9 (
page 224)
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.Deactivating
Press button| (page 224).
The indicator lamp on the button goes
out. Defrosting is turned off.
The previous settings are once again in
effect.Windshield fogged on the outside
Switch the windshield wipers on
(
page 59).
Press buttonU (page 224).
The indicator lamp on button U
goes out. Air volume and air
distribution are controlled separately
for each zone.
If the automatic air distribution and air
volume are switched off:
Press buttons8 and Y
(
page 224).
iThe air conditioning compressor remains on
even if the indicator lamp in button| goes
out. This helps to prevent the windshield from
fogging.
iTo switch off, you can also press
button´ orU (
page 224).
iKeep this setting selected only until the
windshield is clear again.

231 Controls in detail
3-zone automatic climate control*
Maximum cooling MAXCOOL
If the air distribution control as well as the
airflow volume control are set toU and
there is a high need for cooling, the
MAXCOOL function is activated.
“
MAXCOOL” appears in the display.
This provides the fastest possible cooling
of the vehicle interior (when windows and
tilt/sliding sunroof* or tilt/sliding panel*
are closed).
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.Activating
Press button: (page 224).
The indicator lamp on the button
comes on.
Warning!G
Fogged windows impair visibility, endanger-
ing 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 window
fogging persists, make sure the air
conditioning (
page 233) is activated, or
press button|.
iThe air recirculation mode is activated
automatically at high outside temperatures.
The indicator lamp on button:is not lit
when the air recirculation mode is switched on
automatically.
A quantity of outside air is added after
approximately 30 minutes.
If you have turned off the air conditioning
(
page 233) 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 automatic climate control automatically
switches to air recirculation. The indicator lamp
on button: is not lit when the system
switches to air recirculation automatically.

232 Controls in detail
3-zone automatic climate control*
Deactivating
Press button: (page 224).
The indicator lamp on the button goes
out.
At outside temperatures above
79°F (26°C) the system will not automati-
cally switch back to outside air. A quantity
of outside air is added after approximately
30 minutes.Air recirculation mode with
convenience closing and opening
feature
Vehicles with tilt/sliding sunroof*
Convenience closing:
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding
sunroof will close. You can release
button: once the closing proce-
dure has begun. The windows and
tilt/sliding sunroof continue closing
until they are fully closed. The indicator
lamp on the button comes on. The air
recirculation mode is activated.
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* or tilt/sliding panel* if there is the
possibility of anyone being harmed by the
opening or closing procedure.
In case the procedure causes potential
danger:
Vehicles with or without tilt/sliding
sunroof*: The closing of the windows can be
immediately halted by pressing or pulling
the respective window switch. The closing of
the tilt/sliding sunroof* can be immediately
halted by moving the switch for the
tilt/sliding sunroof* in any direction.
The closing of the windows and the
tilt/sliding sunroof* can be reversed by
again pressing and holding the: button.
Vehicles with panorama roof*: The closing
of the windows and tilt/sliding panel* can
be immediately halted by releasing
the:button.
iA window, the tilt/sliding sunroof*, or the
tilt/sliding panel* will only return to its previous
position if it has not been moved to another
position using the respective window switch or
tilt/sliding sunroof* (or tilt/sliding panel*)
switch after it was closed with button:.

233 Controls in detail
3-zone automatic climate control*
Convenience opening:
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding
sunroof will return to their previous
positions. You can release button:
once the opening procedure has
begun. The windows and tilt/sliding
sunroof continue opening until they
have reached their previous positions.
The indicator lamp on the button goes
out. The air recirculation mode is
deactivated.Vehicles with panorama roof*
Convenience closing:
Press and hold button: until the
windows and the tilt/sliding panel are
closed or have reached the desired po-
sition. The indicator lamp on the button
comes on. The air recirculation mode is
activated.
Convenience opening:
Press and hold button: until the
windows and the tilt/sliding panel are
opened or have reached the desired
position. The indicator lamp on the
button goes out. The air recirculation
mode is deactivated.
Air conditioning
The cooling function, only operational
when the engine is running, cools the
vehicle down to the selected interior
temperature. The cooling function also
dehumidifies the air in the vehicle interior,
thereby preventing the windows from
fogging up.
iCondensation may drip out from underneath
the vehicle. This is normal and not an indication
of a malfunction.
Warning!G
If you turn off the cooling function, the
interior air is not dried. The windows can fog
up more quickly. Window fogging may
impair visibility and endanger you and
others.

234 Controls in detail
3-zone automatic climate control*
Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the
vehicle will then no longer be cooled or
dehumidified.
Press button9 (page 224).
The indicator lamp on the button goes
out. The cooling function switches off
after a short delay.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Press button9 again.
The indicator lamp on the button
comes on.
The air conditioning uses the refrigerant
R-134a. This refrigerant is free of CFCs
which are harmful to the ozone layer.Using driver-side settings for all
temperature zones
You can use the settings of the driver’s
side, such as temperature, air volume and
air distribution, for all temperature zones.
These settings only need to be made once
and the automatic climate control system
will automatically regulate the settings for
all temperature zones quickly and comfort-
ably.
Activating
Adjust the temperature, air volume and
air distribution (
page 224).
Press button; (page 224).
The indicator lamp on the button
comes on.
The driver-side settings are used for all
temperature zones.
!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.

238 Controls in detail
3-zone automatic climate control*
Adjusting air distribution
Use the air distribution controls3 or5
to adjust the air distribution for the rear
passenger compartment.
The symbols on the controls represent the
following functions:
Adjusting manually
Press the desired air distribution con-
trol.
The indicator lamp on button U
goes out.Adjusting automatically
Press buttonU.
The indicator lamp on the button
comes on. The air distribution is ad-
justed automatically.
Setting the temperature
Use temperature controla (
page 236)
to separately adjust the air temperature of
the rear passenger compartment.
You should raise or lower the temperature
setting in small increments, preferably
starting at 72°F (22°C). The automatic
climate control will adjust to the set
temperature as fast as possible.Increasing the temperature
Turn temperature controla
(
page 236) slightly clockwise.
The rear automatic climate control will
correspondingly adjust the interior air
temperature for the rear passenger
compartment.
Decreasing the temperature
Turn temperature controla
(
page 236) slightly counterclock-
wise.
The rear automatic climate control will
correspondingly adjust the interior air
temperature for the rear passenger
compartment.
SymbolFunction
ZDirects air to the center air
vents
YDirects air to the footwells and
the side air vents
iThe rear automatic climate control will not
cool the air when the air conditioning is switched
off (
page 234).