Page 353 of 585

352 OperationAt the gas stationRefueling
The fuel filler flap is located on the
right-hand side of the vehicle towards the
rear. Locking/unlocking the vehicle with
the SmartKey or the SmartKey with
KEYLESS-GO* automatically
locks/unlocks the fuel filler flap.
Turn off the engine
by turning the SmartKey to
position0 (
page 40). Remove the
SmartKey from the starter switch.
by pressing the KEYLESS-GO*
start/stop button (
page 41).
Open the driver’s door (with the
driver’s door open, starter switch is
now in position0, same as
SmartKey removed from starter
switch).
Briefly push on fuel filler flap at the po-
sition indicated by the arrow.
The fuel filler flap opens slightly.
Warning!
G
Gasoline and diesel fuels are highly flamma-
ble and poisonous. They burn violently and
can cause serious injury.
Never allow sparks, flame or smoking mate-
rials near gasoline or diesel fuel!
Turn off the engine before refueling.
Whenever you are around gasoline or diesel
fuel, avoid inhaling fumes and skin or cloth-
ing contact, extinguish all smoking materi-
als.
Direct skin contact with gasoline or diesel
fuels and the inhalation of gasoline or diesel
fuel vapors can damage your health.
Warning!
G
Do not fill diesel tanks with gasoline. Do not
mix diesel fuel with gasoline. Otherwise the
fuel system and engine could be damaged.
In addition, the vehicle could catch fire.!
Damage resulting from mixing gasoline with
diesel is not covered by the Mercedes-Benz
Limited Warranty.
!
Diesel engine: When filling the diesel fuel
tank using fuel containers, place a filling filter, a
suede cloth or a clean flannel cloth as a filter.
Otherwise, particles from the fuel container
could clog the fuel lines and/or the diesel injec-
tion system.
Page 354 of 585

353 Operation
At the gas station
Open the fuel filler flap completely.
Turn the fuel cap to the left and hold on
to it until possible pressure is released.
Take off the fuel cap.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.
Only fill your tank until the filler nozzle
unit cuts out – do not top up or over-
fill.
Replace the fuel cap by turning it
clockwise until it audibly engages.
Close the fuel filler flap.
You should hear the latch close shut.
!
The fuel filler cap is tethered to the fuel filler
neck. Do not drop the cap. It could damage the
vehicle paint finish.
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.
i
Leaving the engine running and the fuel cap
open can cause the yellow fuel tank reserve
warning lamp to flash and the ?malfunction
indicator lamp (USA only) or the± malfunc-
tion indicator lamp (Canada only) comes on.
For more information, see “Practical hints”
(
page 417).
i
Gasoline engine: Only use premium unlead-
ed gasoline with a minimum Posted Octane Rat-
ing of 91 (average of 96 RON/86 MON).
Information on gasoline quality can normally be
found on the fuel pump.
For more information on gasoline, see “Premium
unleaded gasoline (gasoline engine)”
(
page 547), see “Fuel requirements”
(page 548), and the Factory Approved Service
Products pamphlet.
i
Diesel engine: Only use commercially avail-
able vehicular diesel fuels No. 2 or No. 1 (ASTM
D975 No. 2-D or No. 1-D). Information on diesel
quality can normally be found on the fuel pump.
The sulfur content in diesel fuel should not
exceed 50 parts per million (ppm). When using
diesel fuel with a sulfur content of above
300 ppm, the engine oil interval should be
shortened.
For more information on diesel fuels, refer to the
Factory Approved Service Products pamphlet or
contact an authorized Mercedes-Benz Light
Truck Center.
!
Diesel engine:
The engine is more susceptible to wear and
damage if you use
marine diesel fuel
heating oil
additives
The use of such non-approved fuels and/or
special additives is not covered by the
Mercedes-Benz Limited Warranty.
Page 355 of 585

354 OperationAt the gas stationLow outside temperatures
(diesel engine)
To prevent malfunctions, diesel fuel with
improved cold flow characteristics is of-
fered in the winter months. Check with
your fuel retailer.
Check regularly and before a long trip
Open the hood (
page 356).
Example ML 5001Brake fluid
2Coolant level
3Windshield washer system and
headlamp cleaning system*
Engine oil level
For more information on engine oil, see
“Engine oil” (
page 358).Brake fluid
Coolant
For normal replenishing, use water (pota-
ble water quality).
For more information, see “Coolant level”
(
page 362) and see “Fuels, coolants, lu-
bricants” (
page 543).
!
Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosine. The
fuel system and engine will otherwise be dam-
aged, which is not covered by the
Mercedes-Benz Limited Warranty.
!
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
“Brake fluid” (
page 546).
Page 356 of 585
355 Operation
At the gas station
Windshield/rear window washer
system and headlamp cleaning
system*
For more information on refilling the wash-
er reservoir, see “Windshield/rear window
washer system and headlamp cleaning
system*” (
page 363).
Vehicle lighting
Check function and cleanliness. For infor-
mation on replacing light bulbs, see “Re-
placing bulbs” (page 482).
For more information, see “Exterior lamp
switch” (
page 136).
Tire inflation pressure
For more information, see “Checking tire
inflation pressure” (
page 375).
Page 357 of 585

356 OperationEngine compartmentHood
OpeningWarning!
G
Do not pull the release lever while the vehi-
cle is in motion. Otherwise the hood could
be forced open by passing air flow.
This could cause the hood to come loose
and injure you and/or others.Warning!
G
If you see flames or smoke coming from the
engine compartment, or if the coolant tem-
perature gauge indicates that the engine is
overheated, do not open the hood. Move
away from vehicle and do not open the hood
until the engine has cooled. If necessary,
call the fire department.
Warning!
G
You could be injured when the hood is open
– even when the engine is turned off.
Parts of the engine can become very hot. To
prevent burns, only touch owner serviceable
components described in the Operator’s
Manual and comply with all relevant safety
precautions.Warning!
G
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for ap-
proximately 30 seconds or even restart af-
ter the engine has been turned off. Stay
clear of fan blades.
Warning!
G
Vehicles with gasoline engine:
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnos-
tic socket) of the ignition system
with the engine running
while starting the engine
if ignition is “on” and the engine is
turned manually
Page 358 of 585
357 Operation
Engine compartment
The hood lock release lever is located in
the driver’s footwell.
1Release lever
Pull release lever1 downwards.
The hood is unlocked. Handle2 pro-
trudes slightly from the radiator grille.
If not, lift the hood slightly.2Handle for opening the hood
Press and hold handle2.
The hood is unlocked.
Pull up on the hood in direction of ar-
row and then release it.
The hood will be automatically held
open at shoulder height by gas-filled
struts.
Warning!
G
Vehicles with diesel engine:
The engine is equipped with a high-voltage
electronic control unit for the injection
system. Because of the high voltage it is
dangerous to touch any components of the
injection system (injectors, electrical wires)
with the engine running
while starting the engine
when the ignition is switched on
!
To avoid damage to the windshield wipers or
hood, never open the hood if the wiper arms are
folded forward away from the windshield.
Page 359 of 585

358 OperationEngine compartmentClosing
Let the hood drop from a height of
approximately 1 ft (30 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 headlamps, 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. Increased 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.Checking engine oil level with the
control system (ML 500 only)
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
stationary 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 40).
The standard display (
page 154)
should appear in the multifunction
display.
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 en-
gaged before driving off. Do not continue
driving if the hood can no longer engage af-
ter an accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others.
i
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 360 of 585

359 Operation
Engine compartment
Press buttonk orj on the
multifunction steering wheel until the
following message appears in the mul-
tifunction display:
One of the following messages will
subsequently appear in the
multifunction display:
Engine oil level OK
Add 1.0 qt. to reach max. oil
level(Canada:
1.0 liter
)
Add 1.5 qts. to reach max. oil
level(Canada:
1.5 liters
)
Add 2.0 qts. to reach max. oil
level(Canada:
2.0 liters
)
If necessary, add engine oil
(page 361).
For information on adding engine oil, see
(
page 361).
For more information on engine oil, see
“Technical data” section (
page 543) and
(
page 546).
Other display messages
If the SmartKey or KEYLESS-GO*
start/stop button is not in position2, the
following message will appear:
Switch ignition on
to check engine oil level
Switch on the ignition (
page 40).
If you see the message:
Observe waiting period
If the engine is at operating
temperature, wait 5 minutes before
repeating check procedure.
If the engine is not at operating temper-
ature, wait 30 minutes before repeat-
ing check procedure.
If you see the message:
Engine oil level
Not when engine on
Turn off the engine.
If the engine is at operating tempera-
ture, wait 5 minutes before checking
oil.
If the engine is not at operating temper-
ature 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
i
If you want to interrupt the checking proce-
dure, press the
k
or
j
button on the
multifunction steering wheel.