2007 MERCEDES-BENZ GL450 cooling

232 Controls in detail
3-zone automatic climate control*
1Temperature control, left
2Air distribution and air volume
(automatic, manual)
3Air distribution, driver’s side
4Front defroster
0
or, depending on vehicle production
date,
|
5Increasing air volume
6Rear window defroster
7Air distribution, passenger side
8Rear automatic climate control
on/off
>USA only
™Canada only
9Temperature control, right
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

233 Controls in detail
3-zone automatic climate control*
The automatic climate control is a 3-zone
intelligent automatic climate control sys-
tem. Your vehicle interior is divided into
3 zones.With the help of a sun sensor, the automat-
ic climate control determines the relation
of the sun to the vehicle and automatically
adjusts the inside temperature for every
individual zone.
The automatic climate control is operation-
al whenever the engine is running. It cools
the vehicle’s interior according to the an-
gle and intensity of the sun’s rays, the out-
side temperature and the selected
temperature. You can operate the auto-
matic climate control in either the auto-
matic or manual mode.
Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 232).
Warning!G
When operating the automatic climate con-
trol, the air that enters the passenger com-
partment through the air vents can be very
hot or very cold (depending on the set tem-
perature). This may cause burns or frostbite
to unprotected skin in the immediate area of
the air vents.
Always keep sufficient distance between un-
protected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 232) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.

234 Controls in detail
3-zone automatic climate control*
Deactivating the automatic climate
control system
Deactivating
Press button´ (page 232) until
the displaye (
page 232) is cleared.
The indicator lamp on the button
comes on.Reactivating
Press buttonU(page 232).Warning!G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air pollution)
may require replacement of the filter before its
scheduled interval. A clogged filter will reduce
the air volume to the interior.
If the vehicle interior is hot, ventilate the interior
before driving off, see “Summer opening fea-
ture” (
page 251). The automatic climate con-
trol 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 settings for a short time. Other-
wise the windows could fog up, impairing
visibility and endangering you and others.
iYou can also press button´
(
page 232) on the automatic climate control
panel.
If you press button0 or, depending on
vehicle production date, button |
(
page 232) to reactivate the automatic
climate control system, the defrosting mode is
activated.

235 Controls in detail
3-zone automatic climate control*
Operating the automatic climate
control system in automatic mode
You can switch the automatic climate con-
trol system on and off separately for each
zone as needed.
Activating
Press buttonU (page 232) 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 232) to separately adjust the
air temperature on each side of the
passenger compartment.
The temperature of the interior is ad-
justed automatically.
Deactivating
Press one button of the air distribution
(
page 232) or press button

orQ (
page 232).
The indicator lamp on buttonU
goes out.
Depending on which button you press –
the air distribution button or the air vol-
ume button
orQ – automatic
control of either the air distribution or
air volume is switched off.
Setting the temperature
Use temperature control1 and9
(
page 232) 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 control1
and/or9 slightly clockwise.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
Decreasing
Turn the temperature control1
and/or9 slightly counterclockwise.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
iWhen operating the automatic climate
control 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.

239 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 front and rear
display.
This provides the fastest possible cooling
of the vehicle interior (when windows and
tilt/sliding sunroof* 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 232).
The indicator lamp on the button
comes on.
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 241) is activated, or
press button0 or, depending on vehicle
production date, button|.
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 automatically
switched on.
A quantity of outside air is added after approxi-
mately 30 minutes.
If you have turned off the air conditioning
(
page 241) 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 switch-
es to air recirculation. The indicator lamp on
button: is not lit when the system switches
to air recirculation automatically.

241 Controls in detail
3-zone automatic climate control*
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 be-
gun. The windows and tilt/sliding sun-
roof* continue opening until they have
reached their previous positions. The
indicator lamp on the button goes out.
The air recirculation mode is deactivat-
ed.
Air conditioning
The cooling function, only operational
when the engine is running, cools the vehi-
cle down to the selected interior tempera-
ture. The cooling function also
dehumidifies the air in the vehicle interior,
thereby preventing the windows from fog-
ging up.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the vehi-
cle will then no longer be cooled or dehu-
midified.
Press button9 (page 232).
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.
iA window or the tilt/sliding sunroof* will
only return to its previous position if it has not
been moved to another position using the re-
spective window switch or tilt/sliding sunroof*
switch after it was closed with button:.
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.

244 Controls in detail
3-zone automatic climate control*
Activating rear automatic climate
control
Press buttonU.
The indicator lamp on the button
comes on. The temperature, air vol-
ume, and air distribution are adjusted
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.Operating from the front
Deactivating
Press button> (page 232).
The indicator lamp on the button goes
out.
In displaye (
page 232), you will see
the> symbol followed by
MODE for
approximately 3 seconds.
Press button´ (page 232).
In displaye (
page 232), you will see
the> symbol followed by
OFF.
The rear automatic climate control is
switched off.Reactivating
Press button> (page 232).
The indicator lamp on the button
comes on.
In displaye (
page 232), 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.
iThe automatic climate control must be
switched on (
page 234).
iSwitch off the rear automatic climate con-
trol 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 com-
partment (
page 232).

383 Operation
Engine compartment
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.
1Cap
2Coolant expansion tank
3Indicator wall
4Coolant levelUsing a rag, turn cap1 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Continue turning cap1 counterclock-
wise and remove it.
Coolant level4 is correct if the level:

for cold coolant: reaches the top of
indicator wall3 visible through the
filling opening

for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap1.
For more information on coolant, see
“Coolants” (
page 565).
Warning!G
In order to avoid potentially serious burns:

Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature gauge indi-
cates that the coolant is overheated.

Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.

Using a rag, slowly open the cap approx-
imately 1/2 turn to relieve excess pres-
sure. If opened immediately, scalding
hot fluid and steam will be blown out un-
der pressure.

Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene gly-
col which may burn if it comes into con-
tact with hot engine parts.