Page 218 of 585
217 Controls in detail
Climate control
Activating
Switch off the ignition (
page 40).
Press button9 (
page 208).
The indicator lamp on the button
comes on.
Deactivating
Press button9 (
page 208).
The indicator lamp on the button goes
out.
Rear climate control*
The control panel for the rear climate
control is only available if your vehicle is
equipped with seat heating* for the rear
seats.
The control panel is located on the rear of
the front center console.Rear climate control panel
i
The residual heat is automatically turned off:
when the ignition is switched on
after about 30 minutes
if the coolant temperature is too low
if the battery voltage drops
1
Left rear center air vent, adjustable
2
Right rear center air vent, adjustable
3
Rear climate control on
(automatic mode)
4
Air distribution (directs air through
the center air vents)
5
Air distribution (directs air through
the footwells and side air vents)
6
Rear air conditioning off
Page 233 of 585

232 Controls in detail3-zone automatic climate control*Residual heat and ventilation
With the engine switched off, it is possible
to continue to heat or ventilate the interior
for up to 30 minutes. This feature makes
use of the residual heat produced by the
engine.Activating
Switch off the ignition (
page 39).
Press button9 (
page 222).
The indicator lamp on the button
comes on.
Deactivating
Press button9.
The indicator lamp on the button goes
out.
Rear automatic climate control
The control panel is located at the rear of
the front center console.
i
How long the system will provide heating
depends on
the coolant temperature
the battery voltage
Regardless of the temperature and air volume
set on the automatic climate control panel, an
interior temperature is aimed at by 72°F (22°C)
and the blower runs on low speed to protect the
vehicle battery.
i
The residual heat is automatically turned off:
when the ignition is switched on
after about 30 minutes
if the coolant temperature is too low
if the battery voltage drops
Page 347 of 585

346 OperationDriving instructions
Adjust the mirrors (
page 49) to
permit unobstructed view beyond rear
of trailer.
If the trailer has electric brakes, start
your vehicle and trailer moving slowly,
and then apply only the trailer brake
controller by hand to make sure the
brakes are working properly.
Always secure items in the trailer to
prevent load shifts while driving.
When towing a trailer, check occasion-
ally to make sure the load is secure,
and that lighting and trailer brakes (if
so equipped) are functioning properly.
Take into consideration that when tow-
ing a trailer, the handling characteris-
tics are different and less stable from
those when operating the vehicle with-
out a trailer.
It is important to avoid sudden maneu-
vers.
The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
It is more prone to reacting to cross
wind gusts, and requires more sensi-
tive steering input.
If possible, do not brake abruptly, but
rather engage the brake slightly at first
to permit the trailer to activate its
brake. Then increase the braking force.
If the transmission repeatedly shifts
between gears on inclines, manually
shift to a lower gear (select 4, 3, 2 or 1)
(page 193).
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 268).
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.
!
If the trailer should begin to sway, reduce
the vehicle’s speed immediately.
In no case attempt to straighten out the tow
vehicle and trailer by increasing the speed.
Page 351 of 585

350 OperationDriving instructionsEmission control
Certain engine systems serve to keep the
toxic components of the exhaust gases
within permissible limits required by law.
These systems, of course, will function
properly only when maintained strictly ac-
cording to factory specifications. Any ad-
justments on the engine should, therefore,
be carried out only by qualified
Mercedes-Benz Light Truck Center autho-
rized technicians.Engine adjustments should not be altered
in any way. Moreover, the specified service
jobs must be carried out regularly accord-
ing to Mercedes-Benz servicing require-
ments. For details refer to the
Maintenance Booklet.
Coolant 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 above 248°F
(120°C). Doing so may cause serious en-
gine damage which is not covered by the
Mercedes-Benz Limited Warranty.
Warning!
G
As with any vehicle, do not idle, park or op-
erate this vehicle in areas where combusti-
ble materials such as grass, hay or leaves
can come into contact with the hot exhaust
system, as these materials could be ignited
and cause a vehicle fire.
Warning!
G
Inhalation of exhaust gas is hazardous to
your health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause un-
consciousness and possible death.
Do not run the engine in confined areas
(such as a garage) which are not properly
ventilated. If you think that exhaust gas
fumes are entering the vehicle while driving,
have the cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one win-
dow fully open at all times.
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 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 363 of 585

362 OperationEngine compartmentTransmission 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.
The coolant expansion tank is located on
the driver’s side of the engine compart-
ment.1Cap
2Coolant expansion tank
3Indicator wall
4Coolant level
Using a rag, turn cap1 slowly approx-
imately one half turn counterclockwise
to release any excess pressure.
Warning!
G
In order to avoid 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 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 364 of 585

363 Operation
Engine compartment
Continue turning cap1 counterclock-
wise and remove it.
Coolant level4 is correct if the level:
for cold coolant: reaches the top of
indicator wall3 visible through the
filling opening
for warm coolant: is approximately
0.6 in (1.5 cm) higher
Add coolant as required.
Replace and tighten cap1.
For more information on coolant, see
“Coolants” (
page 549).Windshield/rear window washer
system and headlamp cleaning
system*
The windshield washer reservoir is located
in the engine compartment.
1Cap for windshield washer fluid
reservoir
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).During all seasons, add MB Windshield
Washer Concentrate “MB SummerFit” to
water. Premix the windshield washer fluid
in a suitable container.
Use the tab to pull cap1 upwards.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.