climate control MERCEDES-BENZ R350 2008 W251 Owner's Guide

223 Controls in detail
3-zone automatic climate control*
1Left side air vent, adjustable
2Windshield air vents
3Thumbwheel for air volume control
for left side and door air vent
4Left center air vent, adjustable
5Right center air vent, adjustable
6Thumbwheel for air volume control
for left center air vent
7Thumbwheel for air volume control
for right center air vent
8Thumbwheel for air volume control
for right side and door air vent
9Right side air vent, adjustable
aFront passenger door air vent, fixed
bAutomatic climate control panel
cFootwell air vents
dDriver’s door air vent, fixed
iFor draft-free ventilation, move the sliders
for center air vents and side air vents to the
middle position.

224 Controls in detail
3-zone automatic climate control*
1Temperature control, driver’s side
2Air distribution and air volume
(automatic, manual)
3Air distribution, driver’s side
4Front defroster
5Increasing air volume
6Rear window defroster
7Air distribution, passenger side
8Rear automatic climate control
on/off
>USA only
™Canada only
9Temperature control, passenger side
aAutomatic climate control on/off
bAir distribution, passenger side
cAir distribution, passenger side
dAC cooling on/off
Residual heat/ventilation
eDisplay
fDecreasing air volume
gAir recirculation
hAir distribution, driver’s side
jAir distribution, driver’s side
kInterior temperature sensor
lAdopting driver’s side settings for all
zones

225 Controls in detail
3-zone automatic climate control*
The automatic climate control is a 3-zone
intelligent automatic climate control
system. Your vehicle interior is divided
into 3 zones.With the help of a sun sensor, the
automatic climate control determines the
relation of the sun to the vehicle and auto-
matically adjusts the inside temperature
for each individual zone.The automatic climate control is oper-
ational whenever the engine is running. It
cools the vehicle’s interior according to the
angle and intensity of the sun’s rays, the
outside temperature and the selected tem-
perature. You can operate the automatic
climate control in either the automatic or
manual mode.
Nearly all dust particles, pollutants and
odors are filtered out before outside air
enters the passenger compartment
through the air distribution system.
Warning!G
When operating the automatic 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 frost-
bite to unprotected skin in the immediate
area of the air vents.
Always keep sufficient distance between
unprotected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 224) 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 replacement 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.

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.

227 Controls in detail
3-zone automatic climate control*
Operating the automatic climate
control system in automatic mode
You can switch the automatic climate
control system on and off separately for
each zone as needed.
Activating
Press buttonU (page 224) while
the engine is running.
The indicator lamp on the button
comes on. Air volume and air distribu-
tion are controlled separately for each
zone.
Use temperature controls1 and9
(
page 224) to separately adjust the
air temperature on each side of the
passenger compartment.
The temperature of the interior is
adjusted automatically.
Deactivating
Press one button of the air distribution
(
page 224) or press button

orQ (
page 224).
The indicator lamp on the buttonU
goes out.
Depending on which button you press –
the air distribution button or the air vol-
ume button
or Q – automatic
control of either the air distribution or
air volume is switched off.
Setting the temperature
Use temperature controls1 and9
(
page 224) 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 automatic climate control will adjust
to the set temperature as fast as possible.
Increasing
Turn temperature control
1and/or9 slightly clockwise.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
Decreasing
Turn temperature control
1and/or9 slightly counterclock-
wise.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
iWhen operating the automatic climate con-
trol system in automatic mode, you will only
rarely need to adjust the temperature, air volume
and air distribution.
In automatic mode, cooling with dehumidify is
switched on. This function can be switched off if
necessary.

228 Controls in detail
3-zone automatic climate control*
Adjusting air distribution
Use the air distribution buttons3,h,
orj for the driver’s side, or7,b, orc
(
page 224) for the passenger side to
separately adjust the air distribution on
each side of the passenger compartment.
The following symbols are found on the
buttons:
Press the desired air distribution
button (
page 224).
The indicator lamp on the desired
button comes on.
Adjusting the air distribution for the
center and side air vents
Opening the center air vents
Turn thumbwheels 6 and 7
(
page 222) upward.
The corresponding center air vents on
the left and right are open.
Closing the center air vents
Turn thumbwheels 6 and 7
(
page 222) downward.
The corresponding center air vents on
the left and right are closed.Opening the side air vents
Turn thumbwheels 3 and 8
(
page 222) upward.
The corresponding side air vents on the
left and right are open.
Closing the side air vents
Turn thumbwheels 3 and 8
(
page 222) downward.
The corresponding side air vents on the
left and right are closed.
SymbolFunction
Driver’s
sidePassen-
ger side
6ZDirects air to the
windshield and
side air vents
7aDirects air through
the center, side
and rear passen-
ger compartment
air vents
8YDirects air to the
footwells and side
air vents

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:.