1997 MERCEDES-BENZ ML500 tow

176 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. ten 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 172)
when the indicator lamp does not light
up in red or stays on longer than ap-
proximately ten seconds.

196 OperationDriving instructionsParking
Tires
Tread wear indicators (TWI) are required by
law. These indicators are located in six
places on the tread circumference and be-
come visible at a tread depth of approxi-
mately
1/16
in (1.6 mm), at which point
the tire is considered worn and should be
replaced.
!Set the parking brake whenever park-
ing or leaving the vehicle. In addition,
move gear selector lever to positionP.
When parking on hills, always turn front
wheels towards the curb.
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 positionP.


When parked on an incline, turn front
wheel towards the road curb.
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-
ti o n t o an a r ea wh ic h is a s a fe d is ta n c e fr o m
the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have it towed to the nearest
Mercedes-Benz Light Truck Center or tire
dealer for repairs.

202 OperationDriving instructionsRims

Dented or bent rims can cause tire
pressure loss and damage the tire
beads. For this reason, check and, if
necessary, change rims before driving
off-road.
Vehicle tool kit


Check if the vehicle jack is functional.


In all cases take the vehicle tool kit, a
strong tow rope, a shovel and a small
plank (to put under the vehicle jack on
sandy soil) with you.
Driving in steep terrain
Slope angle1 25°
226°

Switch to LOW RANGE mode before
starting to drive up or down steep in-
clines (
page 125).


Driving on embankments, slopes and
other steep inclines should only be
done straight up or downhill, i.e. in the
line of gravity. Maximum vehicle climb-
ing ability is a 60% grade.


Do not drive along the side of a slope
(danger of vehicle rollover). If in doing
so, the vehicle begins to show a ten-
dency to roll, immediately steer into a
line of gravity (straight up or downhill).


To help avoid the vehicle rolling over,
never turn it around on steep inclines.
If the vehicle cannot complete the at-
tempted climb, back it down in reverse
gear.


Utilize the engine’s braking power
when descending a slope, observe the
engine speed (do not overview the en-
gine). Apply the service brake as need-
ed.


Check the brakes after a lengthy down-
grade drive.
Traction in steep terrain


Be easy on the accelerator and watch
for continuous wheel traction when
driving in steep terrain.
The 4-ETS helps greatly when starting
out on a steep incline when the front
wheels have then the tendency to slip
due to the weight shifting away the
front axle.iAvoid excessive engine speeds – drive
with moderate engine speeds
(max. 3000 RPM).
Select gear range2 or1 on the auto-
matic transmission (
page 121).

205 Operation
Driving instructions


Check the vehicle clearance before
crossing obstacles.


Select gear range1 on the automatic
transmission (
page 121).


Cross obstacles (e.g. tree stumps or
big rocks) very slowly by aiming one of
the front wheels at the center of the ob-
stacle, and repeat same with the rear
wheel.Ruts
A number of off-road tracks or other by-
ways have deep ruts which can cause the
undercarriage to come in contact with the
ground.


Select gear range1 on the automatic
transmission (
page 121).


Drive next to the ruts rather than
through them if at all possible.Returning from off-road driving
!Special attention is needed when you
cross obstacles on a steep incline.
The vehicle could slide sideways as a
result of its possible slanted position
which in turn may result in the vehicle
tipping or rolling over.
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.

206 OperationDriving instructionsOff-road driving increases strain on the
vehicle.
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 125).


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.
Trailer towingWarning!
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.

207 Operation
Driving instructions
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.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 receiver.
front
rear
2976 lbs
3858 lbs
(1350 kg)
(1750 kg)

208 OperationDriving instructionsLoading 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
vehicle’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”.Attaching a trailer
Observe maximum permitted trailer
dimensions (width and length).
Most states and all Canadian provinces
require


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.
iWe recommend loading the trailer in
such a manner that it has a tongue
weight (TW) between 10% and 15% of
the GTW.

209 Operation
Driving instructions
Towing a trailer
There are many different laws, including
speed limit restrictions, having to do with
trailer towing. Make sure your rig will be le-
gal, 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 tiresAdjust 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.
!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.