2006 MERCEDES-BENZ G55AMG cooling

56 Getting started
Driving
The coolant temperature is above
248°F (120°C)
The coolant is too hot and is no longer
cooling the engine.
Stop the vehicle as soon as possible
and turn off the engine. Allow engine
and coolant to cool.
Check the coolant level and add cool-
ant if necessary (
page 248).In case of accident
If the vehicle is leaking gasoline:
Do not start the engine under any
circumstances.
Notify local fire and/or police
authorities.
If the extent of the damage cannot be
determined:
Notify an authorized Mercedes-Benz
Light Truck Center.
If no damage can be determined on the

major assemblies

fuel system

engine mount:
Start the engine in the usual manner.
i
Excessive coolant temperatures trigger
a warning message in the multifunction
display (
page 308).

169 Controls in detail
Climate control
Climate control panel
1Windshield defroster air vents
2Center air vent, adjustable
3Thumbwheel for center air vent
4Side air vent, adjustable
5Side defroster air vent, fixed
6Thumbwheel for side air vent
7Footwell air vents
8Climate control panel
i
For draft-free ventilation, move the
sliders for the center air vents to the
middle position.
1Air volume
2Temperature control, left
(driver side)
3Temperature control, right
(passenger side)
4Air distribution control
5Rear window defroster (page 166)
6AC cooling on / off (ACOFF)
Residual engine heat utilization
(REST)
7Air distribution and air volume
(automatic mode)
8Air recirculation
9Defrosting

170 Controls in detail
Climate control
The climate control is operational whenev-
er the engine is running. You can operate
the climate control system in either the au-
tomatic or manual mode. The system cools
or heats the interior depending on the se-
lected interior temperature and the cur-
rent outside temperature.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 AC
OFF mode is selected
(
page 174).
Setting the temperature
Use temperature controls2 and3 to
separately adjust the air temperature on
each side of the passenger compartment.
You should raise or lower the temperature
setting in small increments, preferably
starting at 72°F (22°C).
Warning!G
When operating the climate control, the air
that enters the passenger compartment
through the air vents in the footwell can be
very hot or very cold (depending on the set
temperature). This may cause burns or frost-
bite on unprotected skin in the immediate
area of the air vents. Always keep sufficient
distance between unprotected parts of the
body and the footwell air vents. If necessary,
change the air flow using the air distribution
controls to direct the air away from the foot-
well air vents (
page 171).
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.
i
If the vehicle interior is hot, ventilate
the interior before driving off.
Keep the air intake grille in front of the
windshield free of snow and debris.
i
When operating the climate control
system in automatic mode, you will
only rarely need to adjust the tempera-
ture, air volume, and air distribution.

174 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.
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 button°.
The indicator lamp on the button°
comes on.Activating
Moist air can fog up the windows. You can
dehumidify the air with the air conditioner.
Press button° again.
The indicator lamp on the button°
goes out.
The air conditioner uses the refrigerant
R134a. This refrigerant is free of CFCs
which are harmful to the ozone layer.Rear passenger compartment
adjustable air vents
1Air volume control for center air vents
2Left center air vent, adjustable
3Right center air vent, adjustable
i
Condensation may drip out from under-
neath the vehicle. This is normal and
not an indication of a malfunction.
!
If the° button on the climate con-
trol panel starts to blink, this indicates
that the air conditioner is losing refrig-
erant. The compressor has turned itself
off. The air conditioner cannot be
turned on again.

Have the air conditioner checked at
the nearest authorized
Mercedes-Benz Light Truck Center.

248 Operation
Engine compartment
Screw oil filler cap2 back on filler
neck.
For more information on engine oil, see the
“Technical data” section (
page 376) and
(
page 377).
Transmission fluid level
The transmission fluid level does not need
to be checked. The transmission has a per-
manent supply of automatic transmission
fluid.
If you notice transmission fluid loss or gear
shifting malfunctions, have an authorized
Mercedes-Benz Light Truck Center check
the automatic transmission.
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 engine must be cool. The coolant
level should reach the Cold Level mark
(plastic bridge) in the reservoir.
!
Excess oil must be siphoned or drained
off. It could cause damage to the
engine and catalytic converter not
covered by the Mercedes-Benz Limited
Warranty.Warning!G
In order to avoid any possibly 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 in-
dicates 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 1/2turn 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.


307 Practical hints
What to do if …
Display symbolDisplay messagePossible causePossible solution
B COOLANT
CHECK LEVEL!The coolant level is too low.Add coolant (page 248).
If you have to add coolant frequently,
have the cooling system checked by
an authorized Mercedes-Benz Light
Truck Center.
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
the 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 serious
engine damage.
Observe the coolant temperature dis-
play (
page 120).

310 Practical hints
What to do if …
ÏCOOLANT
VISIT WORKSHOP!The cooling fan for the coolant is
malfunctioning.Observe the coolant temperature dis-
play (
page 120).
Have the fan replaced as soon as pos-
sible.
ÑCRUISE CONTROL
VISIT WORKSHOP!Cruise control is malfunctioning.Visit an authorized Mercedes-Benz
Light Truck Center.
JDOOR OPEN!You are attempting to drive with one ore
more doors open.Close the doors.
eENGINE AIR FILTER
VISIT WORKSHOP!The engine air filter is clogged and must
be replaced.Visit an authorized Mercedes-Benz
Light Truck Center as soon as possi-
ble.
Display symbolDisplay messagePossible causePossible solution

377 Technical data
Fuels, coolants, lubricants, etc.
Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, only use
approved engine oils and oil filters re-
quired for vehicles with Maintenance
System (U.S. vehicles) or FSS (Canada
vehicles). For a listing of approved engine
oils and oil filters, refer to the Factory
Approved Service Products pamphlet, or
contact an authorized Mercedes-Benz
Light Truck Center.Using engine oils and oil filters of specifica-
tion other than those expressly required
for the Maintenance System (U.S. vehi-
cles) or FSS (Canada vehicles), or changing
of oil and oil filter at change intervals
longer than those called for by the
Maintenance System (U.S. vehicles) or
FSS (Canada vehicles) will result in engine
damage not covered by the
Mercedes-Benz Limited Warranty.Please follow Maintenance System (U.S.
vehicles) or FSS (Canada vehicles) recom-
mendations for scheduled oil changes.
Failure to do so will result in engine dam-
age not covered by the Mercedes-Benz
Limited Warranty.
ModelCapacityFuels, coolants, lubricants, etc.
Cooling systemG 500
G55AMGapprox. 12.7 US qt (12.0 l)
approx. 13.4 US qt (12.7 l)MB Anticorrosion/Antifreeze
Air conditioning systemR-134a refrigerant and
special PAG lubricant oil (never R-12)
Windshield/rear window washer system
and headlamp cleaning systemapprox. 7.9 US qt (7.5 l)MB Windshield Washer Concentrate
and water1
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing point or MB Windshield Washer Concentrate “S” and commercially available
premixed windshield washer solvent / antifreeze for temperatures below freezing point. Follow suggested mixing ratios (page 382).