2007 MERCEDES-BENZ G55AMG cooling

61 Getting started
Driving
Problems while driving
The engine runs erratically and misfires

An ignition cable may be damaged.

The engine electronics may not be
operating properly.

Unburned gasoline may have entered
the catalytic converter and damaged it.
Give very little gas.
Have the problem repaired at an
authorized Mercedes-Benz Light Truck
Center as soon as possible.The coolant temperature is above
248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle in a safe location as
soon as possible and turn off the
engine. Allow engine and coolant to
cool off.
Check the coolant level and add
coolant if necessary (
page 274).In case of accident
If the vehicle is leaking fuel:
Do not start the engine under any
circumstances.
Notify local fire and/or police
authorities.
If the extent of the damage cannot be
determined:
Contact an authorized Mercedes-Benz
Light Truck Center or call Roadside
Assistance.
If no damage can be determined on the

major assemblies

fuel system

engine mount:
Start the engine in the usual manner.
iExcessive coolant temperatures trigger a
warning message in the multifunction display
(
page 348).

183 Controls in detail
Climate control
Climate control panel (U.S. vehicles)
Climate control panel (Canada vehicles)
Item
1Left side defroster air vent, fixed
2Left side air vent, adjustable
3Thumbwheel for air volume control
for left side air vent
4Left front defroster air vent
5Thumbwheel for air volume control
for left center air vent
6Left center air vent, adjustable
7Right center air vent, adjustable
8Thumbwheel for air volume control
for right center air vent
9Right front defroster air vent
aThumbwheel for air volume control
for right side air vent
bRight side air vent, adjustable
cRight side defroster air vent, fixed
dRight footwell air vent
eClimate control panel
fLeft footwell air vent
iFor draft-free ventilation, move the sliders
for the center air vents and side air vents to the
middle position.Item
1Air volume control
2Left side temperature control
3Right side temperature control
4Air distribution control
5Rear window defroster (page 181)
6AC cooling on/off
Residual heat/ventilation
7Air distribution and air volume
(automatic mode)
8Air recirculation
9Front defroster

184 Controls in detail
Climate control
The climate control is operational when-
ever the engine is running. You can oper-
ate the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.Nearly all dust particles, pollutants and
odors are filtered out before outside air
enters the passenger compartment
through the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 189).
Warning!G
When operating the 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 frostbite on unpro-
tected 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 distri-
bution control (
page 186) to direct the air
to air vents in the vehicle interior that are
not in the immediate area of unprotected
skin.
Warning!G
Follow the recommended settings for
heating and cooling given on the following
pages. 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 193). The 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.

185 Controls in detail
Climate control
Deactivating the climate control
system
Deactivating
Set air volume control1 (page 183)
to position0.
Reactivating
Make sure the ignition is switched on
(
page 39).
Set air volume control1 (page 183)
to any speed.
The previous settings are once again in
effect.Operating the climate control system
in automatic mode
Activating
Press buttonU (page 183) while
the engine is running.
The indicator lamp on the button
comes on. The air volume and air
distribution are adjusted automatically.
Use temperature controls2 and3
(
page 183) to separately adjust the
air temperature on each side of the
passenger compartment.
The interior air temperature is adjusted
automatically.Deactivating
Press buttonU (page 183) once
more.
The indicator lamp on the button goes
out. The automatic operation of the air
volume and air distribution switches
off.
Setting the temperature
Use temperature controls2 and3
(
page 183) 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.
Warning!G
When the climate control 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.
iWhen operating the 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
by pressing button9 if necessary
(
page 189).

188 Controls in detail
Climate control
Deactivating
Press button0 orP
(
page 183) once more.
The indicator lamp on the button goes
out. Defrosting is switched off.
Windshield fogged on the outside
Switch the windshield wipers on
(
page 58).
If the automatic mode of the climate
control is switched off:
Turn air distribution control4
toaorY (
page 183).
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 183).
The indicator lamp on the button
comes on.
iThe cooling remains switched on.
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 189) is activated, or
press button0 orP.
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 auto-
matically.
A quantity of outside air is added after approxi-
mately 30 minutes.
If you have turned off the air conditioning
(
page 189) or the outside temperature is
below 41°F (5°C), the air recirculation mode will
not switch on automatically.

189 Controls in detail
Climate control
Deactivating
Press button, (page 183) once
more.
The indicator lamp on the button goes
out.
Air conditioning
The cooling function, only operational
when the engine is running, cools the
vehicle interior down to the selected
temperature. The cooling function also
dehumidifies the air in the vehicle interior,
thus preventing the windows from fogging
up.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 183).
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.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 is
turned off

after 30 minutes if the outside temperature
is above approximately 41°F (5°C)
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.

274 Operation
Engine compartment
Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze.
When checking the coolant level,

the vehicle must be parked on level
ground

the coolant temperature must be be-
low 158°F (70°C)The coolant expansion tank is located on
the passenger side of the engine compart-
ment.
1Cap
Warning!G
In order to avoid any 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 display
indicates 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
approximately 1/2turn to relieve excess
pressure. If opened immediately, scald-
ing hot fluid and steam will be blown out
under pressure.

Do not spill antifreeze on hot engine
parts. Antifreeze contains ethylene
glycol which may burn if it comes into
contact with hot engine parts.

347 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
;(USA only)
! (Canada only)
Release
parking
brakeYou are driving with the parking brake
set.Release the parking brake
(
page 55).
2Brake
wearThe brake pads have reached their wear
limit.Have the brake pads replaced as
soon as possible.
BTop up
coolant
See
Operator’s
ManualThe coolant level is too low.Add coolant (page 274).
If you have to add coolant frequently,
have the cooling system checked at
an authorized Mercedes-Benz Light
Truck Center.
!Brake pad thickness must be visually
checked by a qualified technician at the intervals
specified in the Maintenance Booklet.
Warning!G
Do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. You could be seriously burned.
!Do not ignore the low engine coolant level
warning. Extended driving with this message and
symbol displayed may cause serious engine
damage not covered by the Mercedes-Benz
Limited Warranty.
Do not drive without sufficient amount of coolant
in the cooling system. The engine will overheat,
causing major engine damage.