MERCEDES-BENZ R320 2008 W251 Owner's Manual

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.

235 Controls in detail
3-zone automatic climate control*
Deactivating
Press button; (page 224) again.
The indicator lamp on the button goes
out.
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 39).
Press button9 (page 224).
The indicator lamp on the button
comes on.
Deactivating
Press button9.
The indicator lamp on the button goes
out.
iIf you manually set the temperature, air
volume or air distribution for the passenger side
or the rear passenger compartment when the
MONO setting is active, the MONO setting will
be switched off.
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 automatic climate control panel, an
interior temperature is aimed at by 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

236 Controls in detail
3-zone automatic climate control*
Rear automatic climate control
(second row)
The control panel is located at the rear of
the front center console.
Rear automatic climate control panel
Activating rear automatic climate
control
Press buttonU.
The indicator lamp on the button
comes on. The temperature, air
volume, and air distribution are ad-
justed automatically.
Deactivating rear automatic climate
control
Press button´.
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.
1Increasing air volume
2Air distribution and air volume
(automatic, manual)
3Air distribution (directs air through
the side air vents)
4Right rear center air vent, adjustable
5Air distribution (directs air through
the footwells and side air vents)
6Rear automatic climate control
on/off
7Decreasing air volume
8Left rear center air vent, adjustable
9Indicator lamps for air volume
settings
aTemperature control
iThe stored values for the rear automatic
climate control are erased from memory after
the ignition has been switched off for more than
30 minutes. Once the front automatic climate
control is switched on again, the rear automatic
climate control operates in automatic mode at a
preset temperature of 72°F (22°C).
iThe automatic climate control must be
switched on (
page 226).
iSwitch off the rear automatic climate
control for improved cooling or heating output in
the front passenger compartment.
You can also switch off the rear automatic
climate control from the front passenger
compartment (
page 237).

237 Controls in detail
3-zone automatic climate control*
Operating from the front
Deactivating
Press button> (page 224).
The indicator lamp on the button
comes on.
In displaye (
page 224), you will see
the >symbol followed by
MODE for
approximately 3 seconds.
Press button´ (page 224).
In displaye (
page 224), you will see
the >symbol followed by
OFF.
The rear automatic climate control is
switched off.Reactivating
Press button> (page 224).
The indicator lamp on the button
comes on.
In displaye (
page 224), you will see
the >symbol followed by
ON and
MODE. The MODE display is cleared and
the indicator lamp on button>
goes out after approximately
3 seconds.
The rear automatic climate control
switches on.Setting the temperature
Make sure the front automatic climate
control is switched on (
page 226).
Press button> (page 224).
The indicator lamp on the button
comes on.
In displaye (
page 224), you will see
the >symbol followed by
MODE.
Set the desired temperature for the
rear passenger compartment using
temperature control 9 (
page 224).
After approximately 3 seconds after
the last adjustment, the display
switches back to its standard display
and the indicator lamp on button>
goes out.
iYou can also press the>button once
more to switch back to the standard display.

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).

239 Controls in detail
3-zone automatic climate control*
Adjusting air volume
Adjusting manually
Five blower speeds are available.
Press button
to decrease or
buttonQ to increase air volume to
the desired level.
The indicator lamp on buttonU
goes out. The selected blower speed is
shown by the indicator lamps for air
volume settings 9 (
page 236).
Adjusting automatically
Press buttonU.
The indicator lamp on the button
comes on. The air volume is adjusted
automatically.B-pillar air vents
Air vents are located in both B-pillars.
1Air vent, adjustable
2Thumbwheel for air volume controlAdjusting air volume
Turn thumbwheel 2 to the left to
increase the air volume.
or
Turn thumbwheel 2 to the right to
decrease the air volume.
Adjusting air distribution
Move air vent slider 1 to the left, right,
up, or down to direct the air in the de-
sired direction.