climate control MERCEDES-BENZ R350 2008 W251 User Guide

213 Controls in detail
Climate control
Deactivating
Press button
orQ
(
page 210).
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 210).
or
Press air distribution button 5,9,
ora (
page 210).
The indicator lamp on buttonU
goes out. The automatic operation of
air distribution switches off.
Setting the temperature
Use temperature controls1 and7
(
page 210) 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 control1and/or
7 (
page 210) slightly clockwise.
The climate control system will corre-
spondingly adjust the interior air
temperature.
Decreasing
Turn temperature control1 and/or
7 (
page 210) slightly counterclock-
wise.
The climate control system will corre-
spondingly adjust the interior air
temperature.
Adjusting air distribution
Press air distribution button5,9, ora
(
page 210) to adjust the air distribution.
The following symbols are found on the
buttons:
Press the desired air distribution
button5,9, ora (
page 210).
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

214 Controls in detail
Climate control
Adjusting air volume
Five blower speeds are available.
Press button
to decrease or
buttonQ to increase air volume
(
page 210) to the desired level.
The indicator lamp on buttonU
(
page 210) goes out. The automatic
operation of air volume switches off.
The selected blower speed is
shown in the air volume display b
(
page 210).
Adjusting air volume for the center and
side air vents
Opening the center air vents
Turn thumbwheels 6 and 7
(
page 208) upward.
The corresponding center air vents on
the left and right are open.Closing the center air vents
Turn thumbwheels 6 and 7
(
page 208) downward.
The corresponding center air vents on
the left and right are closed.
Opening the side air vents
Turn thumbwheels 3 and 8
(
page 208) upward.
The corresponding side air vents on the
left and right are open.
Closing the side air vents
Turn thumbwheels 3 and 8
(
page 208) downward.
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 210).
The indicator lamp on the button
comes on.
iKeep this setting selected only until the
windshield or the door windows are clear again.

215 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 210) 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/or7 (
page 210)
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.

216 Controls in detail
Climate control
Deactivating
Press button| (page 210) 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 59).
Press button| (page 210).
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 button 9 or a
(
page 210).
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 210).
iKeep this setting selected only until the
windshield is clear again.
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 219) is activated, or
press button|.

217 Controls in detail
Climate control
Activating
Press button: (page 210).
The indicator lamp on the button
comes on.DeactivatingPress button:.
The indicator lamp on the button goes
out.Air recirculation mode with
convenience 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 of outside air is added after approxi-
mately 30 minutes.
If you have turned off the air conditioning
(
page 219) 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 are 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 dan-
ger:
Vehicles with or without tilt/sliding sun-
roof*: The closing of the windows can be im-
mediately 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.


218 Controls in detail
Climate control
Vehicles with tilt/sliding sunroof*
Convenience closing:
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding sun-
roof 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.Convenience opening:
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding sun-
roof will return to their previous posi-
tions. 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
position. 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.
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:.


219 Controls in detail
Climate control
Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.
In addition, the air conditioning dehumidi-
fies the interior air at outside temperatures
above 41°F (5° C) and helps prevent
window fogging.
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 210).
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 210) 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 39).
Press button9 (page 210).
The indicator lamp on the button
comes on.
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 inte-
rior air is not dried. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
!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, an interior tem-
perature is aimed at by 72°F (22°C) and the
blower runs on low speed to protect the vehicle
battery.

220 Controls in detail
Climate control
Deactivating
Press button9 (page 210) again.
The indicator lamp on the button goes
out.
Rear climate control*
The control panel is located on the rear of
the front center console.
Rear climate control panel
Activating rear climate control
Press buttonU.
The indicator lamp on the button
comes on. The air volume and air distri-
bution are adjusted automatically.
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
iThe rear climate control panel is only avail-
able if your vehicle is equipped with seat heating
for the second-row seats* or Rear Audio
feature* (see separate COMAND System operat-
ing instructions).
1Rear climate control on
(automatic mode)
2Air distribution (directs air through
the center air vents)
3Rear air conditioning off
4Air distribution (directs air through
the footwells and side air vents)
5Right rear center air vent, adjustable
6Left rear center air vent, adjustable
iThe climate control must be switched on
(
page 221).
iThe temperature is adjusted according to
the settings for the front passenger side made
on the front climate control panel (
page 213).

221 Controls in detail
Climate control
Deactivating rear climate control
Press button´.
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.
Operating from the front
Deactivating
Press button: on the front climate
control panel (
page 210).
The indicator lamp on the button
comes on.Reactivating
Press button: on the front climate
control panel (
page 210).
The indicator lamp on the button goes
out. The rear climate control is
adjusted automatically.
Adjusting air distribution
Use the air distribution controls2 or4
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
control2 or4.
The indicator lamp on buttonU
goes out.
Adjusting automatically
Press buttonU.
The indicator lamp on the button
comes on. The air distribution is
adjusted automatically.
Adjusting air volume
The air volume for the rear zone corre-
sponds to the air volume settings for the
front passenger side. You can switch off
the air supply for the rear zone.
You can switch off the supplied amount of
air volume.
Press button´.
The indicator lamp on the button
comes on.
iSwitch off the rear climate control for
improved cooling or heating output in the front
passenger compartment.
You can also switch off the rear climate control
from the front passenger compartment
(
page 221).
SymbolFunction
ZDirects air to the center air
vents
YDirects air to the footwells and
the side air vents

222 Controls in detail
3-zone automatic climate control*