Page 330 of 539

329 Operation
Engine compartment
Other display messages
If the SmartKey or KEYLESS-GO*
start/stop button is not in position2, the
following message will appear:Turn on ignition
to see engine oil level
Switch on the ignition (
page 34).
If you see the message:
Observe waiting time
If the engine is at operating
temperature, wait five 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 five 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
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 “Practical hints” (
page 381).
!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.
Page 331 of 539

330 OperationEngine compartmentChecking engine oil level with the oil
dipstick (ML 350 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 five 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 offTo check the engine oil level with the oil
dipstick, do the following:
Open the hood (
page 326).
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 three seconds to obtain
accurate reading.The oil level is correct when it is between
the lower3 (min.) and upper2 (max.)
mark of the oil dipstick.
If necessary, add engine oil.
For adding engine oil, see (
page 331).
For more information on engine, see the
“Technical data” section (
page 493) and
(
page 495).iThe filling quantity between the upper
and lower marks on the oil dipstick is
approximately 2.1 US qt. (2.0 l).
Page 332 of 539

331 Operation
Engine compartment
Adding engine oil
Example ML 3501Filler cap
Example ML 5001Filler cap
!Only use approved engine oils and oil
filters required for vehicles with
Maintenance System (U.S. vehicles) or
FSS PLUS (Canada vehicles). For a list-
ing of approved engine oils and oil fil-
ters, refer to the Factory Approved
Service Products pamphlet in your ve-
hicle literature portfolio, or contact an
authorized Mercedes-Benz Light Truck
Center.
In addition, check the oil filler cap for
important information pertaining to the
engine oil needing to meet a specific
Mercedes-Benz specification (e.g.
MB 229.5). If such information is print-
ed on the oil filler cap, only use an en-
gine oil from the list of approved engine
oils in the Factory Approved Service
Products pamphlet that meets the
specification indicated on the oil filler
cap.
Using engine oils and oil filters of spec-
ification other than those expressly re-
quired for the Maintenance System
(U.S. vehicles) or FSS PLUS (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 PLUS (Canada
vehicles) will result in engine damage
not covered by the Mercedes-Benz
Limited Warranty.
Page 333 of 539

332 OperationEngine compartment
Unscrew filler cap1 from filler neck.
Add engine oil as required. Be careful
not to overfill 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
“Technical data” (
page 481).
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.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground and the engine
must be cool.
!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 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.
Page 334 of 539
333 Operation
Engine compartment
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.
1Coolant expansion tank
Using a rag, turn the cap slowly approx-
imately one half turn to the left to re-
lease any excess pressure.
Continue turning the cap to the left and
remove it.
The coolant level is correct if the level
for cold coolant: reaches the top of
the indicator wall visible through
the filling opening
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap.
For more information on coolant, see the
“Technical data” section (
page 497).Windshield/rear window washer
system and headlamp cleaning
system*
The windshield washer reservoir is located
in the engine compartment.
1Cap
Fluid for the windshield washer system and
the headlamp cleaning system* is supplied
from the windshield washer reservoir. It
has a capacity of 8.1 US qt (7.7 l).
Page 335 of 539
334 OperationEngine compartmentDuring all seasons, add MB Windshield
Washer Concentrate “S” to water. Premix
the windshield washer fluid in a suitable
container.
Use the tab to pull cap1 upwards.
Refill the reservoir with MB Windshield
Washer Concentrate “S” and water (or
commercially available premixed wind-
shield washer solvent/antifreeze, de-
pending on ambient temperatures).
Always use washer solvent/antifreeze
where temperatures may fall below
freezing point. Failure to do so could
result in damage to the washer
system/reservoir.For more information, see the “Technical
data” section (
page 500).
!Only use washer fluid which is suitable
for plastic lenses. Improper washer
fluid can damage the plastic lenses of
the headlamps.
Warning!
G
Washer solvent/antifreeze is highly flamma-
ble. Do not spill washer solvent/antifreeze
on hot engine parts, because it may ignite
and burn. You could be seriously burned.
Page 370 of 539

369 Operation
Winter driving
Winter driving
Before the onset of winter, have your
vehicle winterized at an authorized
Mercedes-Benz Light Truck Center. This
service includes:
Check of anticorrosion and antifreeze
concentration.
Addition of cleaning concentrate to the
water of the windshield and headlamp
cleaning system. Add MB Concentrate
“S” to a premixed windshield washer
solvent/antifreeze which is formulated
for below freezing temperatures
(page 500).
Battery test. Battery capacity drops
with decreasing ambient temperature.
A well charged battery helps to make
sure that the engine can be started
even at low ambient temperatures.
Tire change. Mercedes-Benz recom-
mends M+S rated radial-ply tires with a
minimum tread depth of approximately 1/6in (4 mm) on all four wheels for the
winter season.
Winter tires
Always use winter tires at temperatures
below 45°F (7°C) and whenever wintry
road conditions prevail. Not all M+S rated
tires provide special winter performance.
Make sure the tires you use show the
mountain/snowflake.marking on the
tire sidewall. These tires meet specific
snow traction performance requirements
of the Rubber Manufacturers Association
(RMA) and The Rubber Association of Can-
ada (RAC) and have been designed specif-
ically for use in snow conditions. Use of
winter tires is the only way to achieve the
maximum effectiveness of the ABS, ESP
®
and SBC in winter operation.
For safe handling, make sure all mounted
winter tires are of the same make and have
the same tread design.Always observe the speed rating of the
winter tires installed on your vehicle. If the
maximum speed for which your tires are
rated is below the speed rating of your
vehicle, you must place a notice to this
effect where it will be seen by the driver.
Such notices are available from your tire
dealer or from any authorized
Mercedes-Benz Light Truck Center.
Warning!
G
Winter tires with a tread depth under
1/6in
(4 mm) must be replaced. They are no long-
er suitable for winter operation.
Page 371 of 539

370 OperationWinter driving
Block heater (Canada only)
The engine is equipped with a block
heater.
The electrical cable may be installed at an
authorized Mercedes-Benz Light Truck
Center.Snow chains
Snow chains should only be driven on
snow-covered roads at speeds not to
exceed 30 mph (50 km/h). Remove chains
as soon as possible when driving on roads
without snow.Please observe the following guidelines
when using snow chains:
Use of snow chains is not permissible
with all wheel/tire combinations.
Snow chains should only be used on
the rear wheels. Follow the manufac-
turer’s mounting instructions.
Only use snow chains that are
approved by Mercedes-Benz. Your
authorized Mercedes-Benz Light Truck
C e n t e r w i l l b e g l a d t o a d v i s e y o u o n t h i s
subject.
Use of snow chains may be prohibited
depending on location. Always check
local and state laws before installing
snow chains.
Warning!
G
If you use your spare tire when winter tires
are fitted on the other wheels, be aware that
the difference in tire characteristics may
very well impair turning stability and that
overall driving stability may be reduced.
Adapt your driving style accordingly.
Have the spare tire replaced with a winter
tire at the nearest authorized
Mercedes-Benz Light Truck Center.
iWhen driving with snow chains, you
may wish to deactivate the ESP
®
(
page 97) before setting the vehicle
in motion. This will improve the
vehicle’s traction.
!Even on vehicles with all-wheel-drive
use snow chains on rear tires only.
The use of snow chains is not permissi-
ble with the spare wheel.