2008 MERCEDES-BENZ ML320 trailer

356 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 356) 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 507).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 356) 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
applicable, 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 8% and 15% of the trailer weight
and everything loaded in it.
For more information on trailer tongue
load, see “Loading a trailer” (
page 329).

380 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 (Department of Transportation)
A tire branding symbol which denotes the
tire meets requirements of the
U.S. Department of Transportation.
GAWR (G
ross Axle Weight Rating)
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 Trailer Weight)
The GTW is the weight of the trailer plus
the weight of all cargo, equipment, luggage
etc. loaded on the trailer.GVW (G
ross Vehicle Weight)
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 Vehicle Weight Rating)
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.

382 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.
Total load limit
Rated cargo and luggage load plus
68 kilograms (150 lbs) times the vehicle’s
designated seating capacity.
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 Weight Rating)
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 351).
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.

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.

503 Practical hints
Towing the vehicle
Removing towing eye bolt
Loosen towing eye bolt2 counter-
clockwise with wheel wrench.
Unscrew towing eye bolt2.
Store the towing eye bolt and wheel
wrench back into the vehicle tool kit
(
page 448).
Installing cover
Engage cover1 at top and press at
bottom.
Stranded vehicle
Freeing a stranded vehicle, on which the
wheels are dug into sand or mud, should
be done with the greatest of care, especial-
ly if the vehicle is heavily loaded.
Avoid pulling the vehicle abruptly or diago-
nally, since it could result in damage to the
chassis alignment.
Never try to free a vehicle that is still cou-
pled to a trailer.
If possible, a vehicle equipped with trailer
hitch receiver should be pulled backward
in its own previously made tracks.

531 Index
A
ABS 98
Indicator lamp 400
Messages in the multifunction
display 415
Off-road - ABS 99
Accelerator position, automatic
transmission 190
Accessory weight 379
Accident 64
Active head restraint 88, 127, 458
Adaptive Damping System (ADS)* 255
Air bags 74
Children 75, 89
Front passenger front air bag off
indicator lamp 31, 83
Front, Driver 77
Front, Passenger 77
Occupant Classification System
(OCS) 79
Safety guidelines 76
Side impact (front and rear*) 78
Window curtain 78Air conditioning refrigerant 525
Air conditioning system see
Climate control or
Automatic climate control (3-zone)*
Air conditioning, Cooling 214, 229
Air distribution, Front 209, 224
Air distribution, Rear 217, 233
Air pressure see Tire inflation pressure
Air pump, electric (ML 63 AMG) 485
Air recirculation mode 212, 227
Air suspension program* 254
Adaptive Damping System
(ADS)* 255
Messages in the multifunction
display 447
Vehicle level control* 255
Air vents 217
Air vents, Front 210, 224
Air vents, Rear 234
Air volume 210, 225
Alarm system see Anti-theft systems
Alignment bolt (vehicle tool kit) 450, 483Anticorrosion/antifreeze 529
Antiglare, Interior rear view mirror 199
Antiglare, Rear view mirrors* 199
Antilock Brake System see ABS
Anti-theft systems 107
Anti-theft alarm system 106, 107
Immobilizer 106
Aquaplaning see Hydroplaning
Armrest storage/telephone* compart-
ment
Front 281
Ashtrays (Depending on vehicle
configuration) 285
Aspect ratio 379
ATF 345
Attaching a trailer 330
AUDIO menu 160
Audio menu
CD operation 161
Radio operation 160
Satellite radio* operation 160
Auto-dimming*, Rear view mirrors 199
Automatic central locking, Control
system 175

532 Index
Automatic climate control (3-zone)* 218
Air conditioning, Cooling 229
Air distribution, Front 224
Air distribution, Rear 233
Air recirculation mode 227
Air vents, Front 224
Air volume 225
Control panel, Front 220
Control panel, Rear 231
Deactivating system 222
Defogging 225
Defrosting 225
Maximum cooling, MAXCOOL 226
Rear passenger compartment 231
Rear window defroster 203
Residual engine heat (REST) 230
Using driver-side settings for
all temperature zones 229
Automatic headlamp mode 136
Automatic lighting control, Interior
lighting 142
Automatic locking when driving 125
Automatic shift program
(ML 63 AMG only) 195Automatic transmission 54
Accelerator position 190
Automatic shift program
(ML 63 AMG only) 195
Emergency operation
(Limp-Home Mode) 197
Gear ranges 192
Gear selector lever 54, 183
Gear shifting malfunctions 197
Hill start assist system 191
Kickdown 190
Kickdown, manual shift program
(ML 63 AMG only) 196
Manual shift progam
(ML 63 AMG only) 195
Program mode selector switch
(ML 63 AMG only) 194
Shift program (ML 63 AMG only) 194
Shifting procedure 186
Starting the engine 54
Steering wheel gearshift control 193
Towing a trailer 191
Transmission fluid level 345
Transmission positions 187
Automatic Transmission Fluid see ATFB
Backrest
Seat 44
Seat, Lumbar support 129
Seat, Multicontour* 129
Backup lamps
Messages in the multifunction
display 438
Replacing bulbs 471
Bar 380
BAS 100
Lamps in instrument cluster 400
Messages in the multifunction
display 415
Basic carrier bars* 266
Batteries, SmartKey
Check lamp 110, 113
Messages in the multifunction
display 427
Replacing 461
Battery, Vehicle 489
Charging 496
Disconnecting and connecting 491
Jump starting 497
Removing and installing 491

536 Index
Driving 51, 311
Abroad 334
Hydroplaning 316
In winter 318, 384
Instructions 51, 311
Problems 63
Safety systems 98
Systems 244
Through standing water 319
Through water 324
Driving off 58
Driving safety systems
4-ETS 104
ABS 98
BAS 100
EBP 104
ESP
®100
Driving systems 244
Adaptive Damping System
(ADS)* 255
Air suspension program* 254
Cruise control 244
Downhill Speed Regulation
(DSR) 249
Off-road driving program 253
Parktronic system* 259Rear view camera* 264
Vehicle level control* 255
Driving tips 190
Accelerator position 190
Kickdown 190
E
Easy-entry/exit feature
Activating (driver’s seat)* 176
Easy-entry/exit feature* 46
EBP 104
Indicator and warning lamps 402,
429
Electrical connections
Trailer 329
Electrical fuses see Fuses
Electrical system, Technical data 519
Electronic Brake Proportioning see EBP
Electronic Stability Program see ESP
®
Electronic Traction System see 4-ETS
Emergency calls
Tele Aid 296
Emergency operation
Fuel filler flap 457
Locking/unlocking the vehicle 455,
456Emergency operation
(Limp-Home Mode) 197
Emergency operations
Remote door unlock, Tele Aid 301
Unlocking/opening the tailgate 456
Emergency Tensioning Device see ETD
Emergency, In case of
Battery, Jump starting 497
Engine shut-down 506
First aid kit 448
Flat tire 478
Fuses 504
Hazard warning flasher 141
Instrument cluster, Indicator
lamps 400, 401, 402, 403, 404,
405, 406, 407, 408, 410
Roadside Assistance 12, 298
Towing the vehicle 499
Emission control 335
Information label 511
System warranties 10