trailer MERCEDES-BENZ M-CLASS 2007 User Guide

345 Operation
Driving instructions

Make sure the automatic transmission
is set toP (
page 187).

Set the parking brake for the vehicle
(page 65).

Start the engine (
page 54).

Vehicles with air suspension package*:
Set the vehicle level to Highway
(page 270).

Vehicles with air suspension package*:
Set the ADS* to AUTO or COMFORT
(page 269).

Turn off the engine (
page 66).

Close all doors and the tailgate.

Attach the trailer.

Plug in all electrical connectors.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 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
function properly.
i
The provided vehicle electrical wiring
harness for trailer towing has a brake signal wire
for hook-up to a brake controller.
You should consider using a trailer sway control
system. For further information, see an
authorized Mercedes-Benz Light Truck Center.
i
Vehicles with air suspension package*:
When you are towing a trailer, the vehicle level
always remains in the Highway setting.
The following applies additionally when towing a
trailer:


The vehicle is lowered to the highway level
when it reaches a speed of 5 mph (8 km/h)
if not set to highway level.


The high-speed level is not available.
The restrictions that apply to towing also apply
when using accessories that are connected to
the trailer power socket, such as a bicycle rack.
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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.
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347 Operation
Driving instructions


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

Make sure the automatic transmission
is set toP (
page 187).

Set the parking brake for the vehicle
(page 65).

Start the engine (
page 54).

Close all doors and the tailgate.

Set the parking brake for the trailer.
Warning!
G
Vehicles with air suspension package*:
While you are coupling or decoupling a trail-
er, make sure that you do not

lock or unlock


open or close
a vehicle door or the tailgate.
The vehicle’s level could change and you
could endanger yourself and/or others as a
result.
Make sure that you do not operate the ADS
button* (
page 269) or the vehicle level
control system* (
page 270) when cou-
pling/decoupling the trailer.
Warning!
G
Vehicles with air suspension package*:
As soon as you disconnect the electrical
connection between the trailer and the
vehicle, the vehicle will lower. To help avoid
personal injury, make sure no one is near
the wheel housing or underneath the vehicle
before the electrical connection is discon-
nected.
When you uncouple the trailer, the vehicle is
temporarily raised because the springs are
relieved of load. Be especially careful during
this process, as you could otherwise injure
yourself and/or others. Make sure that any
persons remaining in the vehicle do not
press the switches for vehicle level control
or the ADS*.
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348 OperationDriving instructions
Disconnect all electrical plug connec-
tors.

Uncouple the trailer.

Make sure that the trailer coupling is
free of load.

Turn off the engine (
page 66).
Passenger compartment
Driving abroad
Abroad, there is an extensive
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
directory, you should request pertinent
information from an authorized
Mercedes-Benz Light Truck Center.Control and operation of radio
transmitters
COMAND system, radio and telephone*
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 rear cargo compartment is the preferred
place to carry objects. Always use tie down
rings, and if so equipped, always use parti-
tion net* when transporting cargo. The par-
tition net* cannot secure hard or heavy
objects. Always fasten items being carried
as securely as possible using the cargo
tie-down rings in the cargo floor area and
fastening materials.
Warning!
G
Do not forget that your primary responsibili-
ty is to drive the vehicle. Only operate the
COMAND system, 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 44 feet (approximate-
ly 14 m) every second.
1Observe all legal requirements.
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369 Operation
Tires and wheels
1Driver’s door B-pillar
Following is a discussion on how to work
with the information contained on the
placard with regards to loading your
vehicle.Tire and Loading Information
Your vehicle is equipped with a Tire and
Loading Information placard.Tire and Loading Information placard
1Load limit information on the Tire and
Loading Information placard
The placard showing the load limit informa-
tion is located on the driver’s door B-pillar.

Locate the statement “The combined
weight of occupants and cargo should
never exceed XXX kilograms or
XXX lbs.” on this placard.
The combined weight of all occupants,
cargo/luggage and trailer tongue load
(if applicable) should never exceed the
weight referenced in that statement.
Warning!
G
Do not overload the tires by exceeding the
specified load limit indicated on the placard
on the driver’s door B-pillar. Overloading the
tires can overheat them, possibly causing a
blowout. Overloading the tires can also
result in handling or steering problems, or
brake failure.i
Data shown on placard example are for
illustration purposes only. Load limit data are
specific to each vehicle and may vary from data
shown in the illustration below. Refer to placard
on vehicle for actual data specific to your
vehicle.
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371 Operation
Tires and wheels
Step 4
The resulting figure equals the avail-
able amount of cargo and luggage load
capacity. For example, if the “XXX”
amount equals 1400lbs and there will
be five 150 lbs passengers in your
vehicle, the amount of available cargo
and luggage load capacity is 650 lbs
(1400-750 (5 x150) = 650 lbs).
Step 5

Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely
exceed the available cargo and luggage
load capacity calculated in step 4.Step 6 (if applicable)

If your vehicle will be towing a trailer,
load from your trailer will be trans-
ferred to your vehicle. Consult this
manual to determine how this reduces
the available cargo and luggage load
capacity of your vehicle (
page 373).
The following table shows examples on
how to calculate total and cargo load
capacities with varying seating configura-
tions and number and size of occupants.
The following examples use a load limit
of 1500 lbs. This is for illustration
purposes only. Make sure you are using
the actual load limit for your vehicle stated
on the vehicle’s placard (
page 369).
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372 OperationTires and wheelsThe higher the weight of all occupants, the
less cargo and luggage load capacity is
available.
For more information, see “Trailer tongue
load” (
page 373).
Example
Combined
weight limit
of occu-
pants and
cargo from
placard
Number of
occupants
(driver and
passengers)
Seating
configura-
tion
Occupants weight
Combined
weight of all
occupants
Available cargo/luggage and trailer
tongue weight (total load limit from
placard minus combined weight of
all occupants)
1
1500 lbs
5
front: 2
rear: 3
Occupant 1: 150 lbs
Occupant 2: 180 lbs
Occupant 3: 160 lbs
Occupant 4: 140 lbs
Occupant 5: 120 lbs
750 lbs
1500 lbs - 750 lbs = 750 lbs
2
1500 lbs
3
front: 1
rear: 2
Occupant 1: 200 lbs
Occupant 2: 190 lbs
Occupant 3: 150 lbs
540 lbs
1500 lbs - 540 lbs = 960 lbs
3
1500 lbs
1
front:1
Occupant 1: 150 lbs
150 lbs
1500 lbs - 150 lbs = 1350 lbs
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373 Operation
Tires and wheels
Certification label
Even after careful determination of the
combined weight of all occupants, cargo
and the trailer tongue load (if applicable)
(page 373) as to not exceed the permis-
sible load limit, you must make sure that
your vehicle never exceeds the Gross
Vehicle Weight Rating (GVWR) and the
Gross Axle Weight Rating (GAWR) for ei-
ther the front or rear axle. You can obtain
the GVWR and GAWR from the certification
label. The certification label can be found
on the driver’s door B-pillar, see “Technical
data” (
page 527).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 373) must never exceed the
GVWR.
Gross Axle Weight Rating (GAWR): The to-
tal allowable weight that can be carried by
a single axle (front or rear).
To assure that your vehicle does not ex-
ceed the maximum permissible weight
limits (GVWR and GAWR for front and rear
axle), have the loaded vehicle (including
driver, passengers and all cargo and, if ap-
plicable, trailer fully loaded) weighed on a
suitable commercial scale.Trailer tongue load
The tongue load of any trailer is an impor-
tant weight to measure because it affects
the load you can carry in your vehicle. If a
trailer is towed, the tongue load must be
added to the weight of all occupants riding
and any cargo you are carrying in the
vehicle. The tongue load typically is
between 10% and 15% of the trailer weight
and everything loaded in it.
For more information on trailer tongue
load, see “Loading a trailer” (
page 343).
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395 Operation
Tires and wheels
Bar
Another metric unit for air pressure. There
are 14.5038 pounds per square inch (psi)
to 1 bar; there are 100 kilopascals (kPa)
to 1 bar.
Bead
The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the
rim.
Cold tire inflation pressure
Tire inflation pressure when your vehicle
has been sitting for at least 3 hours or
driven no more than 1 mile (1.6 km).
Curb weight
The weight of a motor vehicle with stan-
dard equipment including the maximum
capacity of fuel, oil, and coolant, and, if so
equipped, air conditioning and additional
optional equipment, but without passen-
gers and cargo.DOT (D
epartment o
f T
ransportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross A
xle W
eight R
ating)
The GAWR is the maximum permissible
axle weight. The gross vehicle weight on
each axle must never exceed the GAWR for
the front and rear axle indicated on the
certification label located on the driver’s
door B-pillar.
GTW (G
ross T
railer W
eight)
The GTW is the weight of the trailer plus
the weight of all cargo, equipment, luggage
etc. loaded on the trailer.GVW (G
ross V
ehicle W
eight)
The GVW comprises the weight of the
vehicle including fuel, tools, spare wheel,
installed accessories, passengers and
cargo and, if applicable, trailer tongue
load. The GVW must never exceed the
GVWR indicated on the certification label
located on the driver’s door B-pillar.
GVWR (G
ross V
ehicle W
eight R
ating)
This is the maximum permissible vehicle
weight of the fully loaded vehicle (weight of
the vehicle including all options, passen-
gers, fuel, and cargo and, if applicable,
trailer tongue load). It is indicated on
certification label located on the driver’s
door B-pillar.
Kilopascal (kPa)
The metric unit for air pressure. There are
6.9 kPa to 1 psi; another metric unit for air
pressure is bars. There are 100 kilopascals
(kPa) to 1 bar.
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397 Operation
Tires and wheels
Tire ply composition and material used
This indicates the number of plies or the
number of layers of rubber-coated fabric in
the tire tread and sidewall. Tire manufac-
turers also must indicate the ply materials
in the tire and sidewall, which include
steel, nylon, polyester, and others.
Tire speed rating
Part of tire designation; indicates the
speed range for which a tire is approved.
Traction
Force exerted by the vehicle on the road
via the tires. The amount of grip provided.
Tread
The portion of a tire that comes into
contact with the road.Treadwear indicators
Narrow bands, sometimes called
“wear bars” that show across the tread of
a tire when only
1/16in (1.6 mm) of tread
remains.
TWR (T
ongue W
eight R
ating)
Maximum permissible weight on trailer
tongue.
Uniform Tire Quality Grading Standards
A tire information system that provides
consumers with ratings for a tire’s traction,
temperature and treadwear. Ratings are
determined by tire manufacturers using
government testing procedures. The
ratings are molded into the sidewall of the
tire.Vehicle maximum load on the tire
Load on an individual tire that is
determined by distributing to each axle its
share of the maximum loaded vehicle
weight and dividing it by two.
Rotating tires
Tire rotation can be performed on vehicles
with tires of the same dimension all
around. If your vehicle is equipped with
tires of the same dimension all around,
tires can be rotated, observing a
front-to-rear rotation pattern that will
maintain the intended rotation (spinning)
direction of the tire (
page 368).
Warning!
G
Rotate front and rear wheels only if they are
of the same dimension.
If your vehicle is equipped with mixed-size
tires (different tire dimensions front vs.
rear), tire rotation is not possible.
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