Page 266 of 457

265 Operation
At the gas station
Only fill your tank until the filler nozzle
unit cuts out – do not top off or
overfill.
Replace fuel filler cap2 by turning it
clockwise until it audibly engages.
Close fuel filler flap1.
You should hear the latch close shut.
Check regularly and before a long trip
For information on quantities and require-
ments of operating agents, see “Fuels,
coolants, lubricants, etc.” (
page 422).
Open the hood (page 267).
G500
1Coolant
2Brake fluid
Warning!G
Overfilling of the fuel tank may create pres-
sure in the system which could cause a gas
discharge. This could cause the gas to spray
back out when removing the fuel pump noz-
zle, which could cause personal injury.
!When refueling the vehicle, make certain
that no gasoline comes into contact with the rear
side marker to prevent damaging the lens.
iMake sure to close the fuel filler flap before
locking your vehicle as the flap locking pin
prevents closing after you have locked the
vehicle.
iLeaving the engine running and the fuel cap
open can cause the? malfunction indicator
lamp (USA only) or the± malfunction indica-
tor lamp (Canada only) comes on.
For more information, see “Practical hints”
(
page 328).
iOnly use premium unleaded gasoline with a
minimum Posted Octane Rating of 91 (average of
96 RON/86 MON). Information on gasoline
quality can normally be found on the fuel pump.
Please contact gas station personnel in case la-
bels on the pump cannot be found.
For more information on gasoline, see “Premium
unleaded gasoline” (
page 426), refer to the
Factory Approved Service Products pamphlet
(USA only), or contact an authorized
Mercedes-Benz Light Truck Center.
Page 267 of 457

266 Operation
At the gas station
G55AMG
1Coolant
2Brake fluidBrake fluid
Coolant
For normal replenishing, use water
(potable water quality).
For more information, see “Coolant level”
(
page 274) and see “Fuels, coolants, lu-
bricants, etc.” (
page 422).Engine oil level
For more information on engine oil, see
“Engine oil” (
page 269).
Windshield/rear window washer sys-
tem and headlamp cleaning system
For more information on refilling the
washer reservoir, see “Windshield/rear
window washer system and headlamp
cleaning system” (
page 275).
Vehicle lighting
Check function and cleanliness.
For information on replacing light bulbs,
see “Replacing bulbs” (
page 377).
For more information, see “Exterior lamp
switch” (
page 117).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 288).
!If you find that the brake fluid in the brake
fluid reservoir has fallen to the minimum mark or
below, have the brake system checked for brake
pad thickness and leaks immediately. Notify an
authorized Mercedes-Benz Light Truck Center
immediately. Do not add brake fluid as this will
not solve the problem.
For more information, see “Practical hints”
(
page 326) and see “Brake fluid”
(
page 425).
Page 270 of 457

269 Operation
Engine compartment
ClosingLower hood and let it drop into lock
from a height of approximately 0.7 ft
(20 cm).
The hood will lock audibly.
Check to make sure the hood is fully
closed.
If you can raise the hood at a point
above the turn signals to the left and
right of the hood, then it is not properly
closed. Open it again and let it drop
with somewhat greater force.
Engine oil
The amount of oil your engine needs will
depend on a number of factors, including
driving style. Higher oil consumption can
occur when
the vehicle is new
the vehicle is driven frequently at
higher engine speeds
Engine oil consumption checks should only
be made after the vehicle break-in period.
Warning!G
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure that the hood is securely
engaged before driving off. Do not continue
driving if the hood can no longer engage
after an accident, for example. The hood
could otherwise come loose while the
vehicle is in motion and endanger you and
others.
!Do not push the hood closed manually, as
this could damage it. !Do not use any special lubricant additives,
as these may damage the drive assemblies.
Using special additives not approved by
Mercedes-Benz may cause damage not covered
by the Mercedes-Benz Limited Warranty.
More information on this subject is available at
any Mercedes-Benz Light Truck Center.
Page 271 of 457

270 Operation
Engine compartment
Checking engine oil level with the
control system
When checking the oil level
the vehicle must be parked on level
ground
with the engine at operating tempera-
ture, the vehicle must have been sta-
tionary for at least 5 minutes with the
engine turned off
with the engine not at operating tem-
perature yet, the vehicle must have
been stationary for at least 30 minutes
with the engine turned off
To check the engine oil level via the
multifunction display, do the following:
Switch on the ignition (page 39).
The standard display (
page 140)
should appear in the multifunction
display.
Press buttonk orj on the
multifunction steering wheel until the
following message appears in the
multifunction display:
One of the following messages will
subsequently appear in the multi-
function display:
Engine oil
level
OK
Add
1.0 qt
to reach
maximum
oil level
(Canada: 1.0 liter)
Add
1.5 qts
to reach
maximum
oil level
(Canada: 1.5 liters)
Add
2.0 qts
to reach
maximum
oil level
(Canada: 2.0 liters)
iIf you want to interrupt the checking
procedure, press buttonk orj on the
multifunction steering wheel.
Page 272 of 457

271 Operation
Engine compartment
If necessary, add engine oil
(
page 273).
For more information on engine oil, see the
“Technical data” section (
page 423) and
(
page 425).
Other display messages
If the SmartKey is not turned to position2
in the starter switch, the following
message will appear:
Switch
ignition on to
check engine
oil level
Switch on the ignition (page 39).
If you see the message:
Observe
waiting time
If the engine is at operating
temperature, wait 5 minutes before
repeating check procedure.
If the engine is not at operating
temperature yet, wait 30 minutes
before repeating check procedure.
If you see the message:
Engine oil
level
Not with
engine on
Turn off the engine.
If the engine is at operating
temperature, wait 5 minutes before
checking oil.
If the engine is not at operating
temperature yet, you must wait
30 minutes before checking oil.
If there is excess engine oil with the engine
at operating temperature, the following
message will appear:
Engine oil
level
Reduce oil
level
Have excess oil siphoned or drained
off. Contact an authorized
Mercedes-Benz Light Truck Center.
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 351).
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and/or
catalytic converter not covered by the
Mercedes-Benz Limited Warranty.
iG 500 only:
Perform the engine oil level check with the oil
dipstick if it cannot be completed with the
control system (
page 272).
In this case we recommend that you have the
system checked at a Mercedes-Benz Light Truck
Center.
Page 273 of 457

272 Operation
Engine compartment
Checking engine oil level with the oil
dipstick (G 500 only)
When checking the oil level
the vehicle must be parked on level
ground
with the engine at operating
temperature, the vehicle must have
been stationary for at least 5 minutes
with the engine turned off
with the engine not at operating
temperature yet, the vehicle also must
have been stationary for at least
5 minutes with the engine turned off
Open the hood (page 267).1Oil dipstick
2Upper mark
3Lower mark
Pull out oil dipstick1.
Wipe oil dipstick1 clean.
Fully insert oil dipstick1 into the
dipstick guide tube.
Pull out oil dipstick1 again after
approximately 3 seconds to obtain
accurate reading.
The oil level is correct when it is
between lower mark3 (min.) and
upper mark2 (max.) of the oil
dipstick.
If necessary, add engine oil
(
page 273).
For more information on engine oil, see the
“Technical data” section (
page 423) and
(
page 425).
For more information on messages in the
multifunction display concerning engine
oil, see the “Practical hints” section
(
page 351).
iThe filling quantity between the upper and
lower marks on the oil dipstick is approximately
2.1 US qt (2.0 l).
Page 274 of 457

273 Operation
Engine compartment
Adding engine oil
G500
1Filler cap
G55AMG
1Filler cap
Unscrew filler cap1 from filler neck.
Add engine oil as required. Never over-
fill with oil.
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
For more information on engine oil, see the
“Technical data” section (
page 423) and
(
page 425).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Light
Truck Center check the automatic trans-
mission.
!Only use approved engine oils and oil filters
required 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 (USA only) in your vehicle literature
portfolio, or contact an authorized
Mercedes-Benz Light Truck Center.
Using engine oils and oil filters of specification
other than those expressly required for the
Maintenance System (U.S. vehicles) 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 or
emission control system damage not covered by
the Mercedes-Benz Limited Warranty.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine and/or
catalytic converter not covered by the
Mercedes-Benz Limited Warranty.
Page 275 of 457

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.