2008 MERCEDES-BENZ GL550 page 164

219 Controls in detail
Climate control
or
Press air distribution button5,9,
ora (
page 216).
The indicator lamp on buttonU
goes out. The automatic operation of
air distribution switches off.
Setting the temperature
Use temperature controls1 and7
(
page 216) 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 216) slightly clock-
wise.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing
Turn temperature control1
and/or7 (
page 216) 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 216) to adjust the air distribution.
The following symbols are found on the
controls:
Press the desired air distribution
button5,9, ora (
page 216).
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
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220 Controls in detail
Climate control
Adjusting air volume
Five blower speeds are available.
Press button
to decrease or
buttonQ to increase air volume
(
page 216) to the desired level.
The indicator lamp on buttonU
(
page 216) goes out. The automatic
operation of air volume switches off.
The selected blower speed is shown in
the air volume displayb
(
page 216).
Adjusting air volume for the center and
side air vents
Opening the center air vents
Turn thumbwheels5 and8
(
page 214) to the right.
The corresponding center air vents on
the left and right are open.Closing the center air vents
Turn thumbwheels5 and8
(
page 214) to the left.
The corresponding center air vents on
the left and right are closed.
Opening the side air vents
Turn thumbwheels3 andb
(
page 214) to the right.
The corresponding side air vents on the
left and right are open.
Closing the side air vents
Turn thumbwheels3 andb
(
page 214) to the left.
The corresponding side air vents on the
left and right are closed.Air vents in the roof liner over the
second-row seats*
1Thumbwheel for air volume control
2Air vent, adjustable
Adjusting air volume
Turn thumbwheel1 d o w n t o d e c r e a s e
the air volume.
or
Turn thumbwheel1 up to increase the
air volume.
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221 Controls in detail
Climate control
Adjusting air distribution
Move air vent slider2 to the left, right,
up, or down to direct the air in the de-
sired direction.
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 216).
The indicator lamp on the button
comes on.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
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 tem-
perature when the front defroster is
switched on. The air flow will remain on the
windshield and door windows.
Press button
to decrease or
buttonQ to increase air volume
(
page 216) 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 216) 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.iKeep this setting selected only until the
windshield or the door windows are clear again.
iThe air conditioning compressor remains on
even if the indicator lamp in button| goes
out. This helps to prevent the windshield from
fogging.
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222 Controls in detail
Climate control
Deactivating
Press button| (page 216) 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 63).
Press button| (page 216).
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
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-dryingIf the automatic air distribution is switched
off:
Press air distribution button9 ora
(
page 216).
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 216).
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 216) is activated, or
press button|.
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223 Controls in detail
Climate control
Activating
Press button: (page 216).
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 224) 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 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/slid-
ing sunroof* in any direction.

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225 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 216).
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 216) 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 42).
Press button9 (page 216).
The indicator lamp on the button
comes on.
Deactivating
Press button9 (page 216).
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
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226 Controls in detail
Climate control
Rear climate control*
The control panel is located on the rear of
the front center console.
Activating rear climate control
Press buttonU.
The indicator lamp on the button
comes on. The air volume and air distri-
bution are adjusted automatically.Deactivating rear climate control
Press button´.
The indicator lamp on the button
comes on.
The cooling function switches off after
a short delay.iThe rear climate control panel is only
available if your vehicle is equipped with seat
heating* for the rear seats or Rear Audio fea-
ture* (see separate COMAND System operating
instructions).
1Left rear center air vent, adjustable
2Right rear center air vent, adjustable
3Rear climate control on
(automatic mode)
4Air distribution (directs air through
the center air vents)
5Air distribution (directs air through
the footwells and side air vents)
6Rear air conditioning off
iThe climate control must be switched on
(
page 227).
iThe temperature is adjusted according to
the settings for the front passenger side made
on the front climate control panel (
page 219).
iSwitch off the rear climate control for im-
proved cooling or heating output in the front pas-
senger compartment.
You can also switch off the rear climate control
from the front passenger compartment
(
page 227).
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227 Controls in detail
Climate control
Operating from the front
Deactivating
Press button: on the front climate
control panel (
page 216).
The indicator lamp on the button
comes on.
Reactivating
Press button: on the front climate
control panel (
page 216).
The indicator lamp on the button goes
out. The rear climate control is adjust-
ed automatically.Adjusting air distribution
Use the air distribution controls4 or5
to adjust the air distribution for the rear
passenger compartment.
The following symbols are found on the
controls:
Adjusting manually
Press the desired air distribution
control4 or5.
The indicator lamp in the Ubutton
goes out.Adjusting automatically
Press buttonU (page 226).
The indicator lamp on the button
comes on. The air distribution is adjust-
ed 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´ (page 226).
The indicator lamp on the button
comes on.
SymbolFunction
ZDirects air to the center air
vents
YDirects air to the footwells and
the side air vents
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