2008 MERCEDES-BENZ GL450 Rear break

346 Operation
In the “Operation” section you will find
detailed information on operating, main-
taining and caring for your vehicle.
The first 1000 miles (1500 km)
The more cautiously you treat your vehicle
during the break-in period, the more satis-
fied you will be with its performance later
on.

Drive your vehicle during the first
1000 miles (1500 km) at varying but
moderate vehicle and engine speeds.

During this period, avoid heavy loads
(full throttle driving) and excessive
engine speeds (no more than
2/3 of
maximum rpm in each gear).

Shift gears in a timely manner.

Avoid accelerating by kick-down.

Do not attempt to slow the vehicle
down by shifting to a lower gear using
the gear selector lever.

Select gear ranges3, 2 or1
(
page 197) only when driving at
moderate speeds (for hill driving).After 1000 miles (1500 km) you may
gradually increase vehicle and engine
speeds to the permissible maximum.
All of the above instructions, as may apply
to your vehicle type, also apply when driv-
ing the first 1000 miles (1500 km) after
the engine, the transfer case, the center
differential or the rear differential has been
replaced.
iAlways obey applicable speed limits.
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366 Operation
Driving instructions
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 Gross
Trailer Weight (GTW) and Tongue
Weight (TW).
The values as measures must not
exceed the weight limits listed under
“Vehicle and trailer weight and ratings”
(
page 365).Attaching a trailerObserve 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 criss-crossed
under the trailer tongue. They must be
attached to the hitch receiver, and not
to the vehicle’s bumper or axle.
Make 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. Check with
your local state laws for specific
requirements.
The switch activates the trailer brakes
in the possible event that the trailer
might separate from the tow vehicle.
Warning!G
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 279) or the vehicle level
control system (
page 279) when cou-
pling/decoupling the trailer.
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367 Operation
Driving instructions
Make sure the automatic transmission
is set toP (
page 191).
Set the parking brake for the vehicle
(
page 67).
Start the engine (page 56).
Set the vehicle level to Highway
(
page 279).
Vehicle with ADS*: Set the ADS* to
AUTO or COMFORT (
page 278).
Turn off the engine (page 68).
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

Adjust the mirrors (page 51) 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.
!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 connector 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.
iWhen 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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573 Index
Battery, Vehicle 528
Charging 535
Disconnecting and connecting 530
Jump starting 536
Removing and installing 530
Bead 416
Beverage holder see Cup holder
Bi-Xenon headlamps* see headlamps
Bolts, Spare wheel 494
Brake fluid 564
Checking 376
Messages in the multifunction
display 469
Brake lamp
Cleaning lenses 429
Messages in the multifunction
display 477
Replacing bulbs 511
Brake pads 348
Messages in the multifunction
display 467
Brakes 348
Warning lamp 437
Break-in period 346
Bulbs, replacing see Replacing bulbsButton for Voice control* system 30,
156
C
California retail buyers and lessees,
Important notice for 11
Camera see Rear view camera*
Can holder see Cup holder
Capacities and recommended
fuel/lubricants 562
Card holder 33, 37, 320
Cargo compartment cover blind 310
Cargo net* 312
Cargo tie-down rings 302
Carpets, Cleaning 433
Carriers* 295
Catalytic converter
(gasoline engine) 371
CD changer 165, 315
CD player 165
Center console
Lower part 33
Upper part (Vehicles with
enhanced off-road package*) 32
Upper part (Vehicles without
enhanced off-road package*) 31Central locking
Automatic 128
Locking/unlocking from the
inside 128
Switch 128
Certification label 550
CHECK ENGINE malfunction indicator
lamp 439, 440
Checking tire pressure electronically with
the Advanced Tire Pressure Monitoring
System (Advanced TPMS)*,
(Canada only) 401
Checking tire pressure electronically with
the Tire Pressure Monitoring System
(TPMS), (USA only) 398
Checklist
Off-road driving 357
Returning from off-road driving 363
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584 Index
Multifunction display messages 449
ABS 451
ABS, ESP
®451
Air suspension 486
Air suspension program 486
Brake fluid 469
Brake lamps 477
Brake pads 467
Coolant 472
Corner-illuminating front fog
lamps* 478
Cruise control 452
Distronic* 453
Doors 474
Downhill Speed Regulation 467
EBP 468
Engine coolant 470, 472
ESP
®441
Fog lamps, Front 478
Fog lamps, Rear 480
Front passenger front air bag 460,
461, 462, 463
Fuel cap 474
Headlamps 477, 478, 480, 482
Hood 474Key, SmartKey 476
Key, SmartKey with
KEYLESS-GO* 475, 476
Lamps 477, 478, 479, 480, 482
Low tire pressure 464, 484, 485
Parking brake 468
Parking lamps 480
Tele Aid 483
Telephone* 483
Turn signals 482
Vehicle battery 466
Windshield washer fluid 483
Multifunction steering wheel 30, 156
Button operation 156
N
Navigation system* 166
See separate COMAND System
operating instructions
Net, Cargo* 312
Net, Parcel 319
Neutral gear position, Automatic
transmission 189
New vehicle, Break-in period 346
Night security illumination 146, 176
Normal occupant weight 417
Number, Vehicle Identification (VIN) 550O
Occupant distribution 417
Occupant safety 74
Active head restraint 90
Air bags 76
Children and air bags 77, 91, 93
Children in the vehicle 91
Fastening the seat belt 53
Front passenger front air bag off
indicator lamp 81, 85, 86
Infant and child restraint systems 92
LATCH-type child seat anchors 95
OCS 81
OCS, Messages in the multifunction
display 460, 461, 462, 463
Seat belts 53, 78
OCS 81
Self-test 86
Odometer 153, 155, 162
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