2008 MERCEDES-BENZ GL550 engine

Our company and staff congratulate you
on the purchase of your new
Mercedes-Benz.
Your selection of our product is a demon-
stration of your trust in our company
name. Furthermore, it exemplifies your de-
sire to own an automobile that will be as
easy as possible to operate and provide
years of service.
Your Mercedes-Benz represents the ef-
forts of many skilled engineers and crafts-
men. To help assure your driving pleasure,
and also the safety of you and your passen-
gers, we ask you to make a small invest-
ment of time:
Please read this manual carefully,
then return it to your vehicle where it
will be handy for your reference.

Please follow the recommendations
contained in this manual. They are de-
signed to acquaint you with the opera-
tion of your Mercedes-Benz.

Please pay attention to the warnings
and cautions contained in this manual.
They are designed to help improve the
safety of the vehicle operator and occu-
pants.
We extend our best wishes for many miles
of safe, pleasurable driving.
Mercedes-Benz USA, LLC
A DaimlerChrysler Company
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Contents
Introduction.......................................... 9
Product information ................................ 9
Operator’s Manual ............................... 10
Service and warranty information .. 10
Important notice for California
retail buyers and lessees of
Mercedes-Benz automobiles .......... 11
Maintenance .................................. 12
Roadside Assistance ...................... 12
Change of address or ownership.... 13
Operating your vehicle
outside the USA or Canada ............ 13
Where to find it .................................... 15
Symbols ............................................... 16
Operating safety .................................. 17
Proper use of the vehicle ............... 17
Problems with your vehicle .................. 18
Reporting safety defects...................... 19
Reporting safety defects ................ 19
Vehicle data recording ......................... 20
Information regarding electronic
recording devices ........................... 20At a glance.......................................... 21
Exterior view ......................................... 22
Cockpit ................................................. 24
Instrument cluster ................................ 26
Instrument cluster ................................ 28
Multifunction steering wheel ................ 30
Center console ..................................... 31
Upper part (Vehicles without
enhanced off-road package*) ......... 31
Upper part (Vehicles with
enhanced off-road package*) ......... 32
Lower part ...................................... 33
Overhead control panel ........................ 34
Door control panel................................ 35
Storage compartments ......................... 36Getting started................................... 39
Unlocking ............................................. 40
Unlocking with the SmartKey ......... 40
Unlocking with KEYLESS-GO*......... 41
Starter switch positions .................. 41
Adjusting .............................................. 45
Seats .............................................. 45
Steering wheel ................................ 48
Mirrors ............................................ 51
Driving .................................................. 53
Fastening the seat belts ................. 53
Starting the engine ......................... 56
Parking brake ................................. 59
Driving off ....................................... 60
Switching on headlamps ................. 61
Turn signals .................................... 62
Windshield wipers ........................... 62
Rear window wiper/washer ............ 64
Problems while driving.................... 65
Parking and locking .............................. 67
Parking brake ................................. 67
Switching off headlamps................. 68
Turning off the engine..................... 68
Releasing seat belts........................ 70
Locking ........................................... 70
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Contents
Power tilt/sliding sunroof* ................ 251
Opening and closing ..................... 251
Synchronizing ............................... 253
Driving systems ................................. 255
Cruise control............................... 255
Distronic* (Canada only) .............. 260
Distance warning function*
(Canada only) ............................... 272
Downhill Speed Regulation
(DSR) ............................................ 273
Off-road driving program
(Vehicles without
enhanced off-road package*) ....... 277
Air suspension program ............... 278
Adaptive Damping System
(ADS)* .......................................... 278
Vehicle level control ..................... 279
Parktronic system* ...................... 288
Rear view camera* ....................... 293Loading .............................................. 295
Carriers* ...................................... 295
Loading instructions..................... 301
Cargo tie-down rings .................... 302
Hooks........................................... 304
Expanding cargo compartment .... 304
Cargo compartment cover blind... 310
Cargo net* ................................... 312
Useful features .................................. 315
Storage compartments ................ 315
Parcel nets ................................... 319
Cup holders.................................. 320
Ashtrays ....................................... 321
Cigarette lighter ........................... 323
Power outlets ............................... 324
Floormats ..................................... 325
Seat cover under third-row seats . 326
Heated steering wheel* ............... 327
Telephone* .................................. 328
Tele Aid ........................................ 331
Garage door opener ..................... 338
Compass ...................................... 344
Infrared reflecting windshield* ..... 344
Operation......................................... 345
The first 1000 miles (1500 km) ......... 346
Driving instructions ........................... 347
Drive sensibly – save fuel............. 347
Drinking and driving ..................... 347
Pedals .......................................... 347
Power assistance ......................... 348
Brakes.......................................... 348
Driving off .................................... 350
Parking......................................... 350
Tires ............................................. 351
Hydroplaning................................ 352
Tire traction ................................. 352
Tire speed rating .......................... 353
Winter driving instructions ........... 353
Standing water............................. 355
Off-road driving ............................ 355
Trailer towing ............................... 364
Passenger compartment .............. 370
Driving abroad ............................. 370
Control and operation of radio
transmitters ................................. 370
Catalytic converter
(gasoline engine).......................... 371
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Contents
Oxidation catalyst
(diesel engine).............................. 371
Emission control .......................... 372
Coolant temperature .................... 372
At the gas station .............................. 374
Refueling ...................................... 374
Check regularly and
before a long trip.......................... 376
Engine compartment ......................... 378
Hood ............................................ 378
Engine oil ..................................... 380
Transmission fluid level ................ 381
Coolant level ................................ 381
Windshield/rear window
washer system and
headlamp cleaning system* ........ 383
Tires and wheels ................................ 384
Important guidelines .................... 384
Tire care and maintenance........... 385
Direction of rotation ..................... 387
Loading the vehicle ...................... 387
Recommended tire
inflation pressure ......................... 393
Checking tire inflation pressure ... 395
Tire labeling.................................. 406
Load identification ....................... 410DOT, Tire Identification
Number (TIN) ................................ 410
Maximum tire load ........................ 412
Maximum tire inflation pressure ... 412
Uniform Tire Quality Grading
Standards (U.S. vehicles) .............. 413
Tire ply material ............................ 415
Tire and loading terminology......... 415
Rotating tires ................................ 418
Winter driving ..................................... 420
Winter tires ................................... 420
Snow chains.................................. 421
Maintenance....................................... 422
Maintenance service indicator
message ....................................... 422
Calling up the maintenance
service indicator display ............... 424
Resetting the maintenance
service indicator ........................... 424
Vehicle care........................................ 425
Cleaning and care of the vehicle ... 425
Practical hints.................................. 435
What to do if … ................................... 436
Lamps in instrument cluster ......... 436
Lamp in center console ................ 447
Vehicle status messages in
the multifunction display .............. 449
Where will I find ...? ............................ 490
First aid kit.................................... 490
Vehicle tool kit.............................. 490
Spare wheel .................................. 494
Unlocking/locking in an emergency .. 496
Unlocking the vehicle ................... 496
Locking the vehicle ....................... 497
Fuel filler flap ................................ 497
Resetting activated head restraints.... 499
Vehicles without Rear seat
entertainment system*................. 499
Vehicles with Rear seat
entertainment system*................. 500
Replacing SmartKey batteries ............ 502
Replacing bulbs .................................. 504
Bulbs............................................. 504
Replacing bulbs for front lamps .... 507
Replacing bulbs for rear lamps ..... 511
Adjusting headlamp aim ............... 514
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Contents
Replacing wiper blades ...................... 516
Front wiper blades ....................... 516
Rear wiper blade .......................... 517
Flat tire .............................................. 519
Preparing the vehicle.................... 519
Mounting the spare wheel ............ 520
Bleeding the fuel system
(diesel engine only) ............................ 527
Battery ............................................... 528
Disconnecting, removing,
reinstalling and
reconnecting the battery .............. 530
Charging the battery .................... 535
Jump starting ..................................... 536
Towing the vehicle ............................. 538
Installing towing eye bolt.............. 540
Stranded vehicle .......................... 542
Fuses ................................................. 543
Fuse box in engine compartment . 544
Fuse box in cargo compartment ... 544
Fuse box in
passenger compartment .............. 545
Emergency engine shut-down ...... 545
Technical data................................. 547
Parts service ...................................... 548
Warranty coverage............................. 549
Loss of Service and Warranty
Information Booklet ..................... 549
Identification labels ........................... 550
Layout of poly-V-belt drive ................. 552
GL 320 CDI .................................. 552
GL 450, GL 550............................ 552
Engine................................................ 553
Rims and tires.................................... 555
Same size tires ............................. 556
Minispare wheel ........................... 558
Electrical system ............................... 559
Main Dimensions ............................... 560
Weights.............................................. 561Fuels, coolants, lubricants ................. 562
Capacities .................................... 562
Engine oils ................................... 564
Engine oil additives ...................... 564
Air conditioning refrigerant .......... 564
Brake fluid.................................... 564
Premium unleaded gasoline
(gasoline engine).......................... 565
Fuel requirements ........................ 565
Gasoline additives
(gasoline engine).......................... 566
Coolants ...................................... 567
Windshield washer system and
headlamp cleaning system*......... 569
Index................................................. 571
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13 Introduction
Operator’s Manual
Change of address or ownership
If you change your address, be sure to
send in the “Change of Address Notice”
found in the Service and Warranty Informa-
tion Booklet, or simply call the
Mercedes-Benz Customer Assistance
Center (in the USA) at
1-800-FOR-MERCedes, or Customer
Service (in Canada) at 1-800-387-0100. It
is in your own interest that we can contact
you should the need arise.
If you sell your Mercedes, please leave all
literature with the vehicle to make it avail-
able to the next operator.
If you bought this vehicle used, be sure to
send in the “Notice of Purchase of Used
Truck” found in the Service and Warranty
Information Booklet, or call the
Mercedes-Benz Customer Assistance
Center (in the USA) at
1-800-FOR-MERCedes, or Customer
Service (in Canada) at 1-800-387-0100.Operating your vehicle outside the USA
or Canada
If you plan to operate your vehicle in for-
eign countries, please be aware that:

service facilities or replacement parts
may not be readily available,

unleaded gasoline for vehicles with
catalytic converters may not be avail-
able; the use of leaded fuels will
damage the catalysts,

gasoline may have a considerably
lower octane rating, and improper fuel
can cause engine damage.
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17 Introduction
Operating safety
Operating safety
Proper use of the vehicle
Proper use of the vehicle requires that you
are familiar with the following information
and rules:

the safety precautions in this manual

the “Technical data” section in this
manual

traffic rules and regulations

motor vehicle laws and safety stan-
dards
Warning!G
Work improperly carried out on electronic
components and associated software could
cause them to cease functioning. Because
the vehicle’s electronic components are in-
terconnected, any modifications made may
produce an undesired effect on other sys-
tems. Electronic malfunctions could
seriously impair the operating safety of your
vehicle.
See an authorized Mercedes-Benz Light
Truck Center for repairs or modifications to
electronic components.
Other improper work or modifications on the
vehicle could also have a negative impact on
the operating safety of the vehicle.
Some safety systems only function while the
engine is running. You should therefore nev-
er turn off the engine while driving.
Warning!G
Heavy blows against the vehicle underbody
or tires/wheels, for example when running
over an obstacle, road debris or a pothole,
may cause serious damage and impair the
operating safety of your vehicle. If you feel a
sudden significant vibration or ride distur-
bance, or you suspect that damage to your
vehicle has occurred, you should turn on
your hazard warning flashers, carefully slow
down, and drive with caution to an area
which is a safe distance from the road.
Inspect the vehicle underbody and
tires/wheels for possible damage. If the ve-
hicle appears unsafe, have it towed to the
nearest authorized Mercedes-Benz Light
Truck Center or other qualified maintenance
or repair facility for further inspection or re-
pairs.
Warning!G
Various warning labels are attached to your
vehicle. These warning labels are intended
to make you and others aware of various
risks. You should not remove any of these
warning labels unless explicitly instructed to
do so by information on the label itself. Re-
moval of any of these labels may cause you
and others to be unaware of certain risks
which may result in an accident and/or per-
sonal injury.
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23 At a glance
Exterior view
ItemPage
1Tailgate122
Power tailgate*123
Cargo compartment

Loading instructions301

Cargo tie-down rings302

Hooks304

Expanding304

Cover blind310

Cargo net*312
Vehicle tool kit490
Spare wheel494
2Rear window defroster212
3Rear lamps505
4Fuel filler flap374
Refueling374
Fuel375,
565
ItemPage
5Exterior rear view mirrors
Adjusting51
Auto-dimming rear view
mirrors*208
Power folding*209
6Towing eye bolt
Installing towing eye bolt540
7Tires and wheels384,
555
Checking tire inflation
pressure395
General information384
Flat tire519
Spare wheel494
8Hood378
Opening378
Engine oil380
Coolant381
ItemPage
9Windshield wipers62
Wiper blades, replacing516
Wiper blades, cleaning431
aWindshield
Cleaning with wiper fluid64
Cleaning431
bRoof rails295
Carriers*296
cPower tilt/sliding sunroof*251
dDoors
Locking and unlocking112
Opening120
Unlocking/locking in an
emergency496
eFront lamps505
fHeadlamp cleaning system*208
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