towing MERCEDES-BENZ ML320 2008 W164 User Guide

263 Controls in detail
Driving systems
Switching the Parktronic system*
on/off
You can switch off the Parktronic system
manually.
The Parktronic switch is located in the
upper part of the center console.
1Parktronic switch
2Indicator lampSwitching off
Press Parktronic switch1.
Indicator lamp2 comes on.
Switching on
Press Parktronic switch1 once more.
Indicator lamp2 goes out.Parktronic system* malfunction
If only the red distance segments illumi-
nate and an acoustic warning sounds,
there is a malfunction in the Parktronic
system. The Parktronic system will auto-
matically switch off after 20 seconds and
the indicator lamp in the Parktronic switch
comes on.
Have the Parktronic system checked
by an authorized Mercedes-Benz Light
Truck Center as soon as possible.
If only the red distance segments illumi-
nate and no acoustic warning sounds, the
Parktronic system sensors are dirty (e.g.
slush, snow or ice) or there is an interfer-
ence from other radio or ultrasonic signals
(e.g. working jackhammers, car wash or
the air brakes of trucks). The Parktronic
system will automatically switch off after
20 seconds and the indicator lamp in the
Parktronic switch comes on.iThe Parktronic system switches on
automatically when you switch on the ignition
(
page 40).
Vehicles with original equipment Mercedes-Benz
Trailer Hitch Kit:
The rear Parktronic sensor will automatically
disengage when towing a trailer.

299 Controls in detail
Useful features
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.
The following is 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.Information button¡
The Information button¡ is located
below the center armrest cover.
1Information button¡
Open the storage compartment
(
page 282).
Press and hold button1 (for longer
than 2 seconds).
A call to the Customer Assistance
Center will be initiated. The button will
flash while the call is in progress. The
message
Connecting Call will appear
in the multifunction display.
iThe indicator lamp on the Roadside
Assistance button• remains illuminated in
red for approximately 10 seconds during the
system self-check after switching on the ignition
(together with the SOS button and the Informa-
tion button¡).
See system self-check (
page 295) if the indi-
cator lamp does not come on in red or stays on
longer than approximately 10 seconds.
If the indicator lamp on the Roadside Assistance
button• is flashing continuously and there
was no voice connection to the Response Center
established, then the Tele Aid system could not
initiate a Roadside Assistance call (e.g. the rele-
vant cellular phone network was not available).
The message
Call Failed appears in the mul-
tifunction display.
Roadside Assistance calls can be terminated us-
ing thet button on the multifunction steer-
ing wheel or the END Button on the COMAND
system.

328 Operation
Driving instructions

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.

Check tires for possible damage.

Inspect vehicle underbody, oil pan,
brake hoses, etc., as well as vehicle un-
derbody for possible damage.

Check for brush or branches caught in
the underbody.

After continued operation in mud,
sand, water or other dirty conditions
clean the brake discs, wheels, brake
pads and check and clean axle joints.

Conduct a brake test.
Trailer towing Trailer hitch*

Only install a trailer hitch receiver ap-
proved for your vehicle.
For information on availability and in-
stallation, contact an 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.
!Brush or branches could increase the possi-
bility of a fire, as well as cut fuel and/or brake
lines, puncture rubber bellows of the axles or
drive shafts.
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 in this manual can result in vehi-
cle damage and/or serious personal injury.
Follow the guidelines below carefully to as-
sure safe trailer operation.
Contact an authorized Mercedes-Benz Light
Truck Center should you require an explana-
tion of information contained in this manual.

331 Operation
Driving instructions
Make sure the automatic transmission
is set toP (
page 185).
Set the parking brake for the vehicle
(
page 65).
Start the engine (page 54).
Vehicles with air suspension program*:
Set the vehicle level to Highway
(
page 255).
Vehicles with air suspension program*:
Set the ADS* to AUTO or COMFORT
(
page 255).
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 understand-
ing 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.
iThe 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, contact an
authorized Mercedes-Benz Light Truck Center.
iVehicles with air suspension program*:
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.

332 Operation
Driving 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 192).
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 253).

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.

354 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 1400 lbs 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 356).
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 Tire and Loading
Information placard (
page 352).


399 Practical hints
What to do if …
Where will I find ...?
Unlocking/locking in an emergency
Resetting activated head restraints
Replacing SmartKey batteries
Replacing bulbs
Replacing wiper blades
Flat tire
Bleeding the fuel system
(diesel engine only)
Battery
Jump starting
Towing the vehicle
Fuses

447 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
nLevel Selection
Not PermittedThe selected vehicle level cannot ad-
justed, because

you are driving too fast for the de-
sired vehicle level

you are towing a trailer

you are using accessories that are
connected to the trailer power
socket, e.g. a bicycle rack
Reduce vehicle speed.
Set the desired vehicle level again
(
page 257).
MalfunctionThe air suspension* is malfunctioning.Do not drive faster than 50 mph
(80 km/h) depending on the set
vehicle level.
Have the vehicle checked at an au-
thorized Mercedes-Benz Light
Truck Center.
Compressor
Cooling DownYou have selected a higher vehicle
level*. Due to frequent level changes
within a short period, the compressor
must first cool down.Let the compressor cool until the
message disappears.
The selected level will be set once
the compressor has cooled down.
!When the message Compressor Cooling
Down
appears in the multifunction display,
driving is still possible. Keep in mind that theride height of the vehicle is not yet reached, so
you can damage the underbody of the vehicle.The selected level will be set once the compres-
sor has cooled.

448 Practical hints
Where will I find ...?
First aid kit
The first aid kit is located on the driver’s
side in the cargo compartment behind the
cover.
1Cover in left side trim panel
2Lock
Turn lock1 90° in direction of arrow.
Fold down cover2.
The first aid kit can be removed.
Vehicle tool kit
The vehicle tool kit is stored under the
cargo compartment floor.
The vehicle tool kit includes:

Towing eye bolt

Wheel wrench

Alignment bolt

Vehicle jack

Fuse chart

Collapsible wheel chock

Wheel bolts for spare wheel1Cargo compartment floor, lowered
2Handle cover
Open the tailgate (page 119).
Push in handle cover2 and pull han-
dle in direction of arrow.
Lift cargo compartment floor1.
iCheck expiration dates and contents for
completeness at least once a year and replace
missing/expired items.

450 Practical hints
Where will I find ...?
Example illustration1
6Wheel wrench
7Vehicle jack2
8Collapsible wheel chock
9Fuse chart
aTowing eye bolt
bAlignment bolt
cSpare wheel boltsVehicle jack
The vehicle jack is located underneath the
cargo compartment floor.
Remove vehicle jack (page 450).
1Depending on production date, your vehicle may
be equipped with a scissors-type vehicle jack.
Thus, appearance and alignment of the items may
vary.
2If your vehicle is equipped with a scissors-type
vehicle jack, a reversible ratchet is also included.
!Depending on vehicle production date your
vehicle may be equipped with a scissors-type
jack (located under the cargo compartment
floor). If so equipped, only use this jack when
jacking up the vehicle as otherwise the vehicle’s
underbody can be damaged. See separate
instructions for scissors-type jack.
!To prevent damage, always disengage the
strap of the securing hook and lower the cargo
compartment floor (
page 448) before closing
the tailgate.
Warning!G
Only use the jack supplied with your vehicle
to lift the vehicle briefly for wheel changes.
If you use the jack for any other purpose,
you or others could be inj ure d, as the ja ck is
designed only for the purpose of changing a
wheel.
When using the jack, observe the safety
notes in the “Mounting the spare wheel”
section (
page 479) and the notes on the
jack.