2008 MERCEDES-BENZ GL450 suspension

384 Operation
Tires and wheels
Contact an authorized Mercedes-Benz
Light Truck Center for information on test-
ed and recommended rims and tires for
summer and winter operation. They can
also offer advice concerning tire service
and purchase.Important guidelines

Only use sets of tires and rims of the
same type and make.

Tires must be of the correct size for the
rim.

Break in new tires for approximately
60 miles (100 km) at moderate
speeds.

Regularly check the tires and rims for
damage. Dented or bent rims can
cause tire inflation pressure loss or
damage to the tire beads.

If vehicle is heavily loaded, check tire
inflation pressure and correct as
required.

Do not allow your tires to wear down
too far. Adhesion properties on wet
roads are sharply reduced at tread
depths of less than
1/8in (3 mm).

When replacing individual tires, you
should mount new tires on the front
wheels first (on vehicles with
same-sized wheels all around).
Warning!G
Replace rims or tires with the same designa-
tion, manufacturer and type as shown on the
original part. Contact an authorized
Mercedes-Benz Light Truck Center for fur-
ther information. If incorrectly sized rims
and tires are mounted:

The wheel brakes or suspension
components can be damaged.

The operating clearance of the wheels
and the tires may no longer be correct.
Warning!G
Worn, old tires can cause accidents. If the
tire tread is badly worn, or if the tires have
sustained damage, replace them.
When replacing rims, only use genuine
Mercedes-Benz wheel bolts specified for the
particular rim type. Failure to do so can
result in the bolts loosening and possibly an
accident.
Retreaded tires are not tested or recom-
mended by Mercedes-Benz, since previous
damage cannot always be recognized on re-
treads. The operating safety of the vehicle
cannot be assured when such tires are used.
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486 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
nLevel Selection
Not PermittedThe selected vehicle level cannot adjust-
ed, because

you are driving too fast for the desired
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 279).
MalfunctionThe air suspension is malfunctioning.Do not drive faster than 50 mph
(80 km/h) depending on the set vehi-
cle level.
Have the vehicle checked at an autho-
rized 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.
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538 Practical hints
Towing the vehicle
Mercedes-Benz recommends that the
vehicle be transported with all wheels off
the ground using flatbed or appropriate
wheel lift/dolly equipment. This method is
preferable to other types of towing.If circumstances do not permit the recom-
mended towing methods, the vehicle may
be towed with all wheels on the ground
only so far as necessary to have the vehicle
moved to a safe location where the recom-
mended towing methods can be employed.
When towing the vehicle with all wheels on
the ground, the vehicle may be towed only
for distances up to 30 miles (50 km) and at
a speed not to exceed 30 mph (50 km/h).
!Do not tow-start the vehicle.
!Use flatbed or wheel lift/dolly equipment,
with the SmartKey in starter switch turned to
position0.
Do not tow with sling-type equipment. Towing
with sling-type equipment over bumpy roads will
damage radiator and supports.
To prevent damage during transport, do not tie
down vehicle by its chassis or suspension parts.
Use the towing eyes.
Switch off the ESP
® (page 105) and the
automatic central locking (
page 128).
!Do not tow with one axle raised. Doing so
could damage the transfer case, which is not
covered by the Mercedes-Benz Limited
Warranty.
All wheels must be on or off the ground. Observe
instructions for towing the vehicle with all
wheels on the ground.
Warning!G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if

the engine will not run

there is a malfunction in the brake
system

there is a malfunction in the power
supply or in the vehicle’s electrical
system
This is necessary to adequately control the
towed vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the automatic trans-
mission is in neutral positionN.
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540 Practical hints
Towing the vehicle
Remove the KEYLESS-GO* start/stop
button from the starter switch
(
page 43).
Insert the SmartKey with
KEYLESS-GO* into the starter switch.
Switch on the ignition.
Depress the brake pedal.
Shift the automatic transmission to
neutral positionN.
Release the brake pedal.
If engaged, release the parking brake
(
page 59).
Switch off the ignition and leave the
SmartKey with KEYLESS-GO* in the
starter switch.
Installing towing eye bolt
Depending on whether you are towing a
vehicle or you are being towed, the towing
eye bolt can be screwed into threaded
holes which are located behind covers on
the right-hand side of each bumper.
1Cover!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach a tow cable, tow rope or tow rod to
the vehicle chassis, frame or suspension parts.
iTo signal turns while being towed with
hazard warning flasher in use, set the starter
switch to position2 and activate combination
switch for left or right turn signal in usual manner
– only the selected turn signal will operate.
Upon canceling the turn signal, the hazard warn-
ing flasher will operate again.

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571 Index
A
ABS 101
Indicator lamp 436
Off-road - ABS 102
ABS, ESP
®
Messages in the multifunction
display 451
Accelerator position, automatic
transmission 195
Accessory weight 415
Accident 66
Active head restraint 90, 133, 499
Adaptive Damping System (ADS)* 278
Air bags 76
Children 77, 91
Front passenger front air bag off
indicator lamp 31, 32, 85
Front, Driver 79
Front, Passenger 79
Occupant Classification System
(OCS) 81
Safety guidelines 78
Side impact (front and rear*) 80
Window curtain 80Air conditioning refrigerant 564
Air conditioning system see
Climate control or
Automatic climate control (3-zone)*
Air conditioning, Cooling 224, 239
Air distribution, Front 219, 234
Air distribution, Rear 227, 243
Air pressure see Tire inflation pressure
Air recirculation mode 222, 237
Air suspension program 278
Adaptive Damping System
(ADS)* 278
Messages in the multifunction
display 486
Vehicle level control 279
Air vents 227
Air vents*, Rear 245
Air vents, Front 220, 234
Air volume 220, 235
Alarm system see Anti-theft systems
Alignment bolt (vehicle tool kit) 492, 524
Anticorrosion/antifreeze 563, 568
Antiglare, Interior rear view mirror 208Antiglare, Rear view mirrors* 208
Antilock Brake System see ABS
Anti-theft systems 110
Anti-theft alarm system 109, 110
Immobilizer 109
Aquaplaning see Hydroplaning
Armrest storage/telephone*
compartment
Front 317
Ashtrays (Depending on
vehicle configuration) 321
Aspect ratio 415
ATF 381
Attaching a trailer 366
AUDIO menu 164
Audio menu
CD operation 165
Radio operation 164
Satellite radio* operation 164
Auto-dimming*, Rear view mirrors 208
Automatic central locking,
Control system 180
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576 Index
Door
Entry lamps 151
Locking, In an emergency 497
Locking/unlocking,
KEYLESS-GO* 41, 71
Locking/unlocking, SmartKey 40, 70
Messages in the multifunction
display 474
Opening from inside/outside 114,
120
Remote door unlock (Tele Aid) 337
Unlocking, Mechanical key 496
Door control panel 35
Door handle 35
Door windows see Power windows
DOT 410, 416
Downhill driving
Cruise control 257
Downhill Speed Regulation (DSR) 273
Messages in the multifunction
display 467
Drinking and driving 347Driving 53, 347
Abroad 370
Hydroplaning 352
In winter 353, 420
Instructions 53, 347
Problems 65
Safety systems 101
Systems 255
Through standing water 355
Through water 360
Tips 195
With Distronic* 270
Driving off 60
Driving safety systems
4-ETS 107
ABS 101
BAS 103
EBP 107
ESP
®103
Driving systems 255
Adaptive Damping System
(ADS)* 278
Air suspension program 278
Cruise control 255
Distronic* (Canada only) 260Downhill Speed Regulation
(DSR) 273
Off-road driving program (Vehicles
without enhanced off-road
package*) 277
Parktronic system* 288
Rear view camera* 293
Vehicle level control 279
E
Easy-entry/exit feature
Activating (driver’s seat)* 181
For third-row seats 130
Easy-entry/exit feature* 48
EBP 107
Indicator and warning lamps 438,
468
Electrical connections
Trailer 365
Electrical fuses see Fuses
Electrical system, Technical data 559
Electronic Brake Proportioning see EBP
Electronic Stability Program see ESP
®
Electronic Traction System see 4-ETS
Emergency calls
Tele Aid 333
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580 Index
Headlamps
Automatic headlamp mode 144
Bi-Xenon* 477, 508
Cleaning lenses 429
Cleaning system* 208, 383
Halogen 507
High beam see High beam flasher
High beam see High beam headlamps
Light sensor, Messages in the
multifunction display 477
Low beam see Low beam headlamps
Manual headlamp mode 144
Messages in the multifunction
display 477, 478, 479, 480, 481,
482
Replacing bulbs 504, 505
Switch 61, 143
Heated seats see Seat heating*
Heated steering wheel* 327
Height adjustment
Vehicle level control (Vehicles with Air
suspension program) 281
Vehicle level control (Vehicles with
enhanced Off-road Package*) 283High beam flasher 61, 147
High beam headlamps
Indicator lamp 29
Messages in the multifunction
display 478
Replacing bulbs 505, 507, 508
Switching on 61, 147
High mounted brake lamp 505
Hill start assist system 196
Hinged quarter windows* see
Power windows
Hood 378
Messages in the multifunction
display 474
Opening 378
Hooks
Loading 304
Horn 25
HVAC see Climate control or
automatic climate control (3-zone)*
Hydroplaning 352I
Identification labels see Labels
Ignition 42, 44, 57
Immobilizer 109
Indicator lamps see Lamps, Indicator and
warning
Infant and child restraint systems see
Children in the vehicle
Inflation pressure see Tires,
Inflation pressures
Information button see Tele Aid
Infrared reflecting windshield* 344
Inside door handle 120
Instrument cluster 26, 28, 152
Illumination brightness 153
Lamps 436
Messages in display see Multifunction
display messages
Multifunction display 155
Outside temperature indicator 153
Selecting language 172
Instrument lighting see Instrument cluster,
Illumination brightness
Instrument panel see Instrument cluster
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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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