Page 319 of 539

318 OperationDriving instructions
If the transmission hunts between
gears on inclines, manually shift to a
lower gear (select 4, 3, 2 or 1).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.
On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(page 248).
When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.
If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.
Extreme care must be exercised since
your vehicle with a trailer will require
additional passing distance ahead than
when driving without a trailer.
Because your vehicle and trailer is
longer than your vehicle alone, you will
also need to go much farther ahead of
the passed vehicle before you can re-
turn to your lane.Uncoupling the trailer
Start the engine (
page 34).
Make sure the automatic transmission
is set toP.
Set the parking brake for the vehicle
(page 52) and for the trailer.
Close all doors and the tailgate.
Detach the trailer immediately after-
ward as follows:
Disconnect all electrical plug connec-
tors.
Uncouple the trailer.
!If the trailer should begin to sway, re-
duce the vehicle’s speed immediately.
In no case attempt to straighten out the
tow vehicle and trailer by increasing
the speed.
Page 323 of 539
322 OperationDriving instructionsCoolant temperature
During severe operating conditions,
e.g. stop-and-go traffic, the coolant tem-
perature may rise close to approximately
248°F (120°C).
The engine should not be operated with
the coolant temperature over 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
Driving when your engine is badly over-
heated can cause some fluids, which
may have leaked into the engine com-
partment to catch fire. You could be se-
riously burned.
Steam from an overheated engine can
cause serious burns and can occur just
by opening the engine hood. Stay away
from the engine if you see or hear steam
coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
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 412 of 539

411 Practical hints
What to do if …
During severe operation conditions and
stop-and-go city traffic, the coolant tem-
perature may rise close to 248°F (120°C).
Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The coolant is too hot.
Stop the vehicle and immediately turn off
the engine.
Only start the engine again after the mes-
sage disappears. You could otherwise
damage the engine.
Warning!
G
Driving when your engine is badly overheat-
ed can cause some fluids which may have
leaked into the engine compartment to
catch fire. You could be seriously burned.
Steam from an overheated engine can cause
serious burns and can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Turn off the engine, get out of the vehicle
and do not stand near the vehicle until the
engine has cooled down.
!The engine should not be operated with
the coolant temperature above 248°F
(120°C). Doing so may cause serious
damage which is not covered by the
Mercedes-Benz Limited Warranty.
Page 413 of 539
412 Practical hintsWhat to do if …Display symbol
Display messages
Possible cause
Possible solution
Ï
Coolant
Stop, engine off
The poly-V-belt could be broken.
Stop the vehicle and immediately turn off
the engine.
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise the
engine will overheat due to an inoperative
water pump which may result in damage
to the engine. Notify an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Do not continue to drive the vehicle with
this message displayed. Doing so could
result in serious engine damage that is
not covered by the Mercedes-Benz Limit-
ed Warranty.
Drive immediately to the nearest autho-
rized Mercedes-Benz Light Truck Center.
Coolant
Visit workshop
The cooling fan for the coolant is
malfunctioning.
Observe the coolant temperature gauge
in the instrument cluster.
Have the fan replaced as soon as possi-
ble.
Page 414 of 539
413 Practical hints
What to do if …
Display symbol
Display messages
Possible cause
Possible solution
G
Display malfunction
Visit workshop
The instrument cluster display is
malfunctioning.
Continue driving with added caution.
Visit an authorized Mercedes-Benz Light
Truck Center as soon as possible.
The displays for several systems
have malfunctioned. Some sys-
tems themselves may also have
malfunctioned.
Have the electronic systems checked by
an authorized Mercedes-Benz Light Truck
Center.
±
Display malfunction
Visit workshop
Certain electronic systems are
unable to relay information to
the control system. The follow-
ing systems may have failed:
Coolant temperature display
Tachometer
Cruise control display
Have the electronic systems checked by
an authorized Mercedes-Benz Light Truck
Center.
J
Doors open
Door open
You are attempting to drive with
one or more doors open.
Close the doors.
Page 494 of 539
493 Technical data
Fuels, coolants, lubricants, etc.
Fuels, coolants, lubricants, etc.
Capacities
Vehicle components and their respective
lubricants must match.Therefore only use products tested and
approved by Mercedes-Benz.Please refer to the Factory Approved
Service Products pamphlet, or inquire at
your Mercedes-Benz Light Truck Center.
Model
Capacity
Fuels, coolants, lubricants, etc.
Engine with oil filter
ML 350
8.5 US qt (8.0 l)
Approved engine oils
ML 500
9.1 US qt (8.5 l)
Approved engine oils
Automatic transmission
9.6 US qt (9.0 l)
MB Automatic Transmission Fluid
Transfer case single speed
0.5 US qt (0.5 l)
MB Automatic Transmission Fluid
Front axle
1.2 US qt (1.1 l)
Hypoid gear oil
Rear axle
1.2 US qt (1.1 l)
Hypoid gear oil
Power steering
approx. 1.3 US qt (1.2 l)
MB Power Steering Fluid
Front wheel hubs
approx. 1.5 oz (43 g) each
High temperature roller bearing grease
Page 495 of 539
494 Technical dataFuels, coolants, lubricants, etc.
Model
Capacity
Fuels, coolants, lubricants, etc.
Cooling system
ML 350
approx. 10.2 US qt (9.5 l)
MB Anticorrosion/Antifreeze
ML 500
approx. 10.7 US qt (10.0 l)
MB Anticorrosion/Antifreeze
Fuel Tank
including a reserve of
ML 350, ML 500
25.0 US gal (95.0 l)
approx. 3.5 US gal (13.0 l)
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)
Air conditioning system
R-134a refrigerant and special PAG lubricant oil
(never R-12)
Windshield washer and
headlamp cleaning*
system
8.1 US qt (7.7 l)
MB Windshield Washer Concentrate
1
1Use MB Windshield Washer Concentrate “S” and water for temperatures above freezing or MB Windshield Washer Concentrate “S” and commercially available
premixed windshield washer solvent/antifreeze for temperatures below freezing. Follow suggested mixing ratios (page 500).