2003 MERCEDES-BENZ ML350 towing

164 Controls in detailUseful featuresWhen the connection is established, the
message
ROADSIDE ASSISTANCE –
CALL CONNECTED
appears in the MCS dis-
play. The Tele Aid system will transmit data
generating the vehicle identification num-
ber, model, color and location (subject to
availability of cellular and GPS signals).
A voice connection between the Roadside
Assistance dispatcher and the occupants
of the vehicle will be established. When a
voice connection is established the audio
system mutes and the message
TELE AID
– ROADSIDE ASSISTANCE CALL ACTIVE
ap-
pears in the MCS display.

Describe the nature of the need for as-
sistance.The Mercedes-Benz Roadside assistance
dispatcher will either dispatch a qualified
Mercedes-Benz technician or arrange to
tow your vehicle to the nearest
Mercedes-Benz Light Truck Center. For
services such as labor and / or towing,
charges may apply. Refer to the Roadside
Assistance manual for more information.
These programs are only available in the
USA:


Sign and Drive services: Services such
as jump start, a few gallons of fuel or
the replacement of a flat tire with the
vehicle spare tire are obtainable,


Remote Vehicle Diagnostics: This func-
tion permits the Mercedes-Benz Road-
side Assistance dispatcher to
download malfunction codes and actu-
al vehicle data.
iWhile the call is connected you can
change to navigation menu by pressing
NAVI button on the MCS unit.
iThe indicator lamp in the Roadside As-
sistance button
•
remains illumi-
nated in red for approx. 10 seconds
during the system self-check after turn-
ing the key in the steering lock to
position2 (together with the SOS but-
ton and the Information button
¡
).
See system self-check (
page 160)
when the indicator lamp does not light
up in red or stays on longer than ap-
proximately 10 seconds.

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.

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.

223 Practical hints
What to do if …
Where will I find ...?
Unlocking/locking in an emergency
Opening/closing in an emergency
Replacing bulbs
Replacing wiper blades
Flat tire
Battery
Jump starting
Towing the vehicle
Fuses

267 Practical hints
Towing the vehicle
Towing the vehicle
Mercedes-Benz recommends that the vehi-
cle be transported with all wheels off the
ground using flatbed or appropriate wheel
lift/dolly equipment. This method is pref-
erable to other types of towing.When circumstances do not permit the
recommended towing methods, the vehi-
cle may be towed with all wheels on the
ground only so far as necessary to have the
vehicle moved to a safe location where the
recommended towing methods can be em-
ployed.
!Use flatbed or wheel lift/dolly equip-
ment, with key in steering lock turned
to position0.
Do not tow with sling-type equipment.
Towing with sling-type equipment over
bumpy roads will damage radiator and
supports.
To prevent damage during transport,
do not tie down vehicle by its chassis or
suspension parts. Use the towing eyes.
Switch off the ESP (
page 76),
tow-away alarm (
page 80) and the
automatic central locking (
page 89).
!When towing the vehicle with all wheels
on the ground, the selector lever must
be in position N and the key m us t be in
steering lock position 2.
When towing the vehicle with all wheels
on the ground, the vehicle may be
towed only for distances up to 30 miles
(50 km) and at a speed not to exceed
30 mph (50 km/h).
If the vehicle is towed with the front
axle raised (observe instructions re-
garding flexible drive shaft), the engine
must be shut off (key in steering lock
position1). Otherwise, the 4-ETS may
become engaged which may cause loss
of towing control.
!To be certain to avoid additional dam-
age to the vehicle powertrain, however
you should observe the following:

With damage to the front axle

raise front axle


remove flexible drive shaft be-
tween rear axle and transfer
case


With damage to the rear axle

raise rear axle


tow vehicle with wheel lift or
dolly placed under front wheels


With damage to the transfer case

remove flexible drive shaft to
the drive axles
Always install new self-locking nuts
when reinstalling flexible drive shaft.

268 Practical hintsTowing the vehicleWarning!
G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if:

the engine will not run


there is a malfunction in the power sup-
ply or in the vehicle’s electrical system
Prior to towing the vehicle with all wheels on
the ground, make certain that the key is in
steering lock position2.
If the key is left in steering lock position0
for an extended period of time, it can no
longer be turned in the switch. In this case,
the steering is locked. To unlock, remove
key from steering lock and reinsert.
Warning!
G
With the engine not running, there is no
power assistance for the braking and steer-
ing systems. In this case, it is important to
keep in mind that a considerably higher de-
gree of effort is necessary to brake and
steer the vehicle. Adapt your driving accord-
ingly.iTo signal turns while being towed with
hazard warning flasher in use, turn key
in steering lock to position2 and acti-
vate combination switch for left or right
turn signal in usual manner – only the
selected turn signal will operate.
Upon canceling the turn signal, the haz-
ard warning flasher will operate again.iThe vehicle cannot be started via
tow-start.
!When towing the vehicle with all wheels
on the ground, note the following:
With the automatic central locking acti-
vated and the key in steering lock
position2, the vehicle doors lock if the
left front wheel is turning at vehicle
speeds of approx. 9 mph (15 km/h) or
more.
To prevent the vehicle doors from lock-
ing, deactivate the automatic central
locking (
page 89).
Towing of the vehicle should only be
done using the towing eye. Never at-
tach tow cable, tow rope or tow rod to
vehicle chassis, frame or suspension
parts.

269 Practical hints
Towing the vehicle
Front towing eye
The front towing eye is located on the pas-
senger side below the bumper.
1Towing eyeRear towing eye The rear towing eye is located behind the
right side cover in the bumper panel.
ML 320, ML 350, ML 5001Cover
2Towing eye
To remove cover:
Pry out the cover1 using a flat blade
screwdriver (
page 237).
To reinstall cover:

Engage cover at bottom and press in
top securely.
iThe selector lever will remain locked in
positionP and the key will not turn in
the steering lock if the battery is dis-
connected or discharged. See notes on
the battery (
page 261) or on jump
starting (
page 264).
Manual unlocking of transmission se-
lector lever (page 245)
Warning!
G
In order to avoid possible serious burns or
injury, use extreme caution when removing
the cover, because the rear exhaust pipe is
extremely hot.