MERCEDES-BENZ ML320 2003 W163 Owner's Manual

191 Operation
Driving instructions
Returning from off-road drivingOff-road driving increases strain on the ve-
hicle.
We recommend that you inspect the vehi-
cle for possible damage after each off-road
trip. Recognizing any damage and a subse-
quent timely repair reduces the chance of
a possible breakdown or accident later on.
Proceed as follows:


Switch off the LOW RANGE mode
(page 118).


Remove excessive dirt from tires,
wheels, wheel housings, and under-
body.
For instance, after driving in mud, clean
the radiator, chassis, engine, brakes,
and wheels from extreme dirt using a
strong jet of water.


Inspect frame, oil pan, brake hoses,
etc., as well as vehicle underbody for
possible damage.


Check tires for possible damage, clean
all exterior lamps, and conduct a brake
test.


Check for brush or branches caught in
the undercarriage.
They could increase the possibility of a
fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the
axles or drive shafts.


After continued operation in mud,
sand, water or other dirty conditions
clean the brake discs, wheels, brake
pads and check and clean axle joints.
Warning!
G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning flash-
ers, carefully slow down, and drive with cau-
tion to an area which is a safe distance from
the roadway.
Inspect the tires and under the vehicle for
possible damage. If the vehicle or tires ap-
pear unsafe, have it towed to the nearest
Mercedes-Benz Light Truck Center or tire
dealer for repairs.

192 OperationDriving instructionsTrailer towing Trailer hitches


Only install a trailer hitch receiver ap-
proved for your vehicle.
For information on availability and in-
stallation, see your authorized
Mercedes-Benz Light Truck Center.


The bumpers on your vehicle are not
designed for use with clamp-type hitch-
es.
Do not attach rental hitches or other
bumper-type hitches to them.


To reduce the possibility of damage, re-
move the hitch ball adaptor from the
receiver when not in use.Electrical connections
The vehicle is prewired to accept the sev-
en-wire harness included in the
Mercedes-Benz approved trailer hitch re-
ceiver kit.
An additional four-pole conversion plug is
included in the Mercedes-Benz supplied
trailer hitch receiver kit.
For further information, see your autho-
rized Mercedes-Benz Light Truck Center.
Warning!
G
Failure to use proper equipment and driving
technique can result in a loss of vehicle con-
trol when towing a trailer.
Improper towing or failure to follow the in-
structions contained in this guide can result
in serious injury. Follow the guidelines be-
low carefully to assure safe trailer operation.
Ask your authorized Mercedes-Benz Light
Truck Center should you require an explana-
tion of information contained in this guide.

193 Operation
Driving instructions
Vehicle and trailer weights and ratings
Gross Vehicle Weight Rating (GVWR) is the
maximum permissible vehicle weight:
6614 lbs. (3000 kg).
Gross Vehicle Weight (GVW):
Comprises weight of vehicle including fuel,
tools, spare wheel, installed accessories,
passengers, cargo and trailer tongue. It
must never exceed the GVWR.
Gross Axle Weight Rating (GAWR) is the
maximum permissible axle weight:
Gross Trailer Weight (GTW) is the maxi-
mum permissible trailer weight to be
towed:
5000 lbs. (2260 kg)
Trailer Tongue Weight Rating (TWR) is the
maximum permissible weight on the trailer
tongue:
500 lbs. (225 kg) limit for Mercedes-Benz
approved hitch receiverLoading a trailer


When loading a trailer, you should ob-
serve that neither the permissible GTW,
nor the GVWR are exceeded.
Maximum permissible values are listed
on the safety compliance certification
labels for the vehicle and for the trailer
to be towed.
The lowest value listed must be select-
ed when determining how the vehicle
and trailer are loaded.


The tongue weight at the hitch ball
must be added to the GVW to prevent
exceeding your Mercedes-Benz tow ve-
hicle’s rear GAWR.Checking weights of vehicle and trailer


To assure that the tow vehicle and trail-
er are in compliance with the maximum
permissible weight limits have the load-
ed rig (tow vehicle including driver, pas-
sengers and cargo, trailer fully loaded)
weighed on a commercial scale.


Check the vehicle’s front and rear
Gross Axle Weight (GAW), the GTW and
TW.
The values as measured must not be
exceeded, according to the weight list-
ed under “Vehicle and trailer weight
and ratings”. front
rear2976 lbs.
3858 lbs(1350 kg)
(1750 kg)
iWe recommend loading the trailer in
such a manner that it has a tongue
weight (TW) between 10% and 15% of
the GTW.

194 OperationDriving instructionsAttaching a trailer
Observe maximum permitted trailer di-
mensions (width and length).
Most states and all Canadian provinces re-
quire

safety chains between your tow vehicle
and the trailer.
The chains should be crisscrossed un-
der the trailer tongue. They must be at-
tached to the hitch receiver, and not to
the vehicle’s bumper or axle.
Be sure to leave enough slack in the
chains to permit turning corners.


a separate brake system at various
trailer weights.


a break-away switch on trailers with a
separate brake system.
The switch activates the trailer brakes
in the possible event that the trailer
might separate from the tow vehicle.Towing a trailer
There are many different laws, including
speed limit restrictions, having to do with
trailer towing. Make sure that your rig will
be legal, not only for where you reside, but
also for where you will be driving. A good
source for this information can be the po-
lice or local authorities.
Note the following points, when driving
with the trailer:


In order to gain skill and an under-
standing of the vehicle’s behavior, you
should practice turning, stopping and
backing up in an area which is free from
traffic.


Before you start driving check the

trailer hitch


break-away switch


safety chains


electrical connections


lighting and tires
!Do not connect a trailer brake system
(if trailer is so equipped) directly to the
vehicle’s hydraulic brake system, as
your vehicle is equipped with antilock
brakes. If you do, neither the vehicle’s
brakes nor the trailer’s brakes will func-
tion properly.iThe provided vehicle electrical wiring
harness for trailer towing has a brake
signal wire (color orange) for hook-up
to a brake controller.
You should consider using a trailer
sway control system. For further infor-
mation see your authorized
Mercedes-Benz Light Truck Center.

195 Operation
Driving instructions
Adjust the mirrors 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 be 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 be sure that 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.
I t i s m o r e p r o n e t o r e a c t i n g t o s i d e w i n d
gusts, and requires more sensitive
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 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 selector lever in position1, switch
transfer case to LOW RANGE mode
(page 118).


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 trailer should begin to sway, re-
duce the vehicle’s speed and use the
brake controller by hand to straighten
out the vehicle and trailer.
In no case should you attempt to
straighten out the tow vehicle and trail-
er by increasing the speed or over-
steering and stepping on the brakes.

196 OperationDriving instructions

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.Parking
Passenger compartment
Warning!
G
To reduce the risk of personal injury, or
damage to the vehicle powertrain, as a re-
sult of vehicle/trailer movement, always:

Keep right foot on brake pedal.


Shift gear selector lever to positionN.


Have a second person place wheel
chocks on downhill side of left and right
trailer wheels.


Slowly release brake pedal and let vehi-
cle and trailer roll into chocks until
stopped.


Firmly depress parking brake pedal.


Move gear selector lever to position P.


When parked on an incline, turn front
wheel towards the road curb.
Warning!
G
Always fasten items being carried as secure-
ly as possible.
In an accident, during hard braking or sud-
den maneuvers, loose items will be thrown
around inside the vehicle, and cause injury
to vehicle occupants unless the items are
securely fastened in the vehicle.
The trunk is the preferred place to carry ob-
jects. Always use partition net when trans-
porting cargo. Partition net cannot secure
hard or heavy objects.

197 Operation
Driving instructions
Driving abroad
Abroad, there is a widely-spread
Mercedes-Benz service network at your
disposal. If you plan to drive into areas
which are not listed in the index of your
Mercedes-Benz Light Truck Center directo-
ry, you should request pertinent informa-
tion from your authorized Mercedes-Benz
Light Truck Center.Control and operation of radio trans-
mitters
MCS, radio and telephone*Telephones and two-way radios
Radio transmitters, such as a portable tele-
phone or a citizens band unit should only
be used inside the vehicle if they are con-
nected to an antenna that is installed on
the outside of the vehicle.
Refer to the radio transmitter operation in-
structions regarding use of an external an-
tenna.Warning!
G
Do not forget that your primary responsibili-
ty is to drive the vehicle. Only operate the
MCS, radio or telephone
1 if road, weather
and traffic conditions permit.
Bear in mind that at a speed of just 30 mph
(approximately 50 km / h), your vehicle is
covering a distance of approximately
44 feet (approximately 13.5 m) every sec-
ond.
1Observe all legal requirements.
Warning!
G
Never operate radio transmitters equipped
with a built-in or attached antenna (i.e. with-
out being connected to an external antenna)
from inside the vehicle while the engine is
running. Doing so could lead to a malfunc-
tion of the vehicle’s electronic system, pos-
sibly resulting in an accident and/or
personal injury.

198 OperationDriving instructionsCatalytic converter
Your Mercedes-Benz is equipped with
monolithic type catalytic converters, an
important element in conjunction with the
oxygen sensors to achieve substantial con-
trol of the pollutants in the exhaust emis-
sions. Keep your vehicle in proper
operating condition by following our rec-
ommended maintenance instructions as
outlined in your Service Booklet.
Emission control
Certain engine systems serve to keep the
toxic components of the exhaust gases
within permissible legal limits.
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. More-
over, the specified service jobs must be carried out regularly according to
Mercedes-Benz servicing requirements.
For details refer to the Service Booklet.
!To prevent damage to the catalytic con-
verters, use only premium unleaded
gasoline in this vehicle.
Any noticeable irregularities in engine
operation should be repaired promptly.
Otherwise, excessive unburned fuel
may reach the catalytic converter,
causing it to overheat and start a fire.
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, and inhaling it can cause uncon-
sciousness and lead to 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.

199 Operation
Driving instructions
Coolant temperature
During severe operating conditions and
stop-and-go city traffic, the coolant tem-
perature may rise to approx. 248°F
(120°C).
The engine should not be operated with
the coolant temperature in the red zone.
Doing so may cause serious engine dam-
age 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 it
cools down.

200 OperationAt the gas station
At the gas stationThe fuel filler flap is located on the
left-hand side of the vehicle towards the
rear. Locking/unlocking the vehicle with
the remote control automatically
locks/unlocks the fuel filler flap.

Remove the key from the steering lock.

Open the fuel filler flap1 by pulling in
direction of the arrow.

Turn the fuel cap2 to the left and hold
on to it until possible pressure is re-
leased.

Take off the cap.

Only fill your tank until the filler nozzle
unit cut out – do not top up or overfill.

Replace the fuel cap by turning it to the
right.
You will hear when the fuel cap is tight-
ened.

Close the fuel filler flap.
Warning!
G
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious inju-
ry. Whenever you are around gasoline, avoid
inhaling fumes and skin contact, extinguish
all smoking materials. Never allow sparks,
flame or smoking materials near gasoline!.
!The fuel filler cap is tethered to the fuel
filler neck. Do not drop the cap. It could
damage the vehicle paint finish.!To prevent damaging the lens of the
plastic tail lamp, make certain that no
gasoline comes into contact with it.
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.iUse only 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.
More information on gasoline can be
found in the Factory Approved Service
Products pamphlet.