2008 MERCEDES-BENZ GL450 Towing

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
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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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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106 Safety and Security
Driving safety systems
Switching on the ESP®
Press ESP® switch1.
The ESP
® warning lampv in the
instrument cluster goes out.
You are now again in normal driving
mode.For more information, see “Practical hints”
(
page 435).
Off-road – ESP
®
With the off-road driving program switched
on (
page 277), or with the transmission
in LOW RANGE* mode (
page 201), the
ESP® designed for off-road use is automat-
ically activated. At speeds below 27 mph
(45 km/h), the ESP
® assists in over-/un-
dersteering, thus improving vehicle trac-
tion.
ESP
® Trailer Stabilization
If the trailer you are towing should begin to
sway, the rig can only be stabilized by
immediately applying the brakes hard.
Steering during this maneuver will not help
to stabilize the rig.
ESP
® will assist you in such situations.
ESP® recognizes when the trailer starts
swaying and will apply the brakes to re-
duce the vehicle speed to a non-critical
speed that allows the vehicle-trailer combi-
nation to stabilize.The ESP
® Trailer Stabilization is functional
at vehicle speeds above approximately
40 mph (65 km/h) when the ESP
® is
switched on.
Warning!G
When the ESP® warning lampv is
illuminated continuously, the ESP® is
switched off or is not operational due to a
malfunction.
Adapt your speed and driving to the prevail-
ing road conditions and to the non-operating
status of the ESP
®.
!Avoid spinning of a drive wheel for an ex-
tended period of time with the ESP® switched
off. This may cause serious damage to the
drivetrain which is not covered by the
Mercedes-Benz Limited Warranty.
WarningG
The system will not be able to assist when
the trailer jackknifes

on wet or icy roads

on roads with slippery surface

in sand or gravel
Trailers with a high center of gravity may tip
over before the system recognizes swaying
of the trailer.
iIf the ESP® has switched off due to a mal-
function, ESP® cannot stabilize the rig.
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128 Controls in detail
Locking and unlocking
Automatic central locking
The doors and the tailgate lock automati-
cally when the ignition is switched on and
the wheels are turning at vehicle speeds of
approximately 9 mph (15 km/h) or more.
For information on towing the vehicle, see
“Towing the vehicle” (
page 538).
You can deactivate the automatic central
locking mode using the control system
(
page 180).
Locking and unlocking from the inside
You can lock or unlock the doors and the
tailgate from inside using the central lock-
ing or unlocking switch. This can be useful,
for example, if you want to lock the vehicle
before starting to drive.
The fuel filler flap cannot be locked or un-
locked with the central locking or unlock-
ing switch.Even with the SmartKey with KEYLESS-GO*
removed from the vehicle, the tailgate
closing switch can be operated. Therefore,
do not leave children unattended in the vehi-
cle, or with access to an unlocked vehicle. A
child’s unsupervised access to a vehicle
could result in an accident and/or serious
personal injury.
iTo prevent a possible inadvertent lockout,
the tailgate will open automatically if a SmartKey
with KEYLESS-GO* is recognized inside the
vehicle.
iYou can open a locked door from the inside.
Open door only when conditions are safe to do
so.
iThe doors unlock automatically after an
accident if the force of the impact exceeds a
preset threshold.
The vehicle automatically locks when the ignition
is switched on and the wheels are turning at
vehicle speeds of approximately 9 mph
(15 km/h) or more. You could therefore lock
yourself out when the vehicle

is pushed or towed

is on a test stand
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. A child’s unsupervised
access to a vehicle could result in an
accident and/or serious personal injury.

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195 Controls in detail
Automatic transmission
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.
Driving tips
Accelerator position
Your driving style influences the
transmission’s shifting behavior:
Less throttle Earlier upshifting
More throttle Later upshifting
!Observe instructions

when taking the vehicle through an
automatic conveyor type car wash
(
page 428)

when towing the vehicle (page 538)
!Coasting the vehicle, or driving for any other
reason in neutral positionN can result in
transmission damage that is not covered by the
Mercedes-Benz Limited Warranty.
Effect
êDrive
The transmission shifts
automatically. All forward gears
are available.
Warning!G
Getting out of your vehicle without shifting
into park positionP is dangerous. Also, park
positionP alone is not intended to or capa-
ble of preventing your vehicle from moving,
possibly hitting people or objects.
Always set the parking brake in addition to
shifting to positionP (
page 67).
When parked on an incline, turn the front
wheels towards the road curb.
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Children could shift the
automatic transmission out of park
positionP, which could result in an accident
and/or serious personal injury.
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197 Controls in detail
Automatic transmission
On uphill grades with a gradient angle of
more than 5°, the hill start assist system
maintains the pressure in the brake sys-
tem for approximately 1 second after you
have released the brake pedal. Therefore,
you can start off smoothly without the
vehicle moving immediately after releasing
the brake pedal.
The hill start assist system is inactive

when starting off on a level road or
downhill grades

with the transmission in neutral
positionN

with the parking brake set

if the ESP® has switched off due to a
malfunctionTowing a trailer
If you tow a trailer, note the following
points:

Manually shift to a lower gear range
(
page 197) if the transmission hunts
between gears on inclines.
A lower gear range and reduction of
speed reduces the chance to overload
or overheat the engine.
For more information on trailer towing, see
the “Operation” section (
page 364).
Gear ranges
With the automatic transmission in drive
positionD, you can select a gear range for
the automatic transmission to operate
within.
You can limit the gear range by pressing
the left gearshift button on the steering
wheel gearshift control, and reverse the
gear range limit by pressing the right gear-
shift button on the steering wheel gearshift
control (
page 198).The selected gear range appears in the
multifunction display.
1Current gear range
Effect
ïThe transmission shifts through
sixth gear only.
îThe transmission shifts through
fifth gear only.
éThe transmission shifts through
fourth gear only.
èThe transmission shifts through
third gear only.
With this selection you can use
the braking effect of the engine.
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201 Controls in detail
Transfer case
Transfer case
LOW RANGE mode*
The LOW RANGE mode is available on vehi-
cles with enhanced off-road package*.
In the following situations you should
switch to LOW RANGE mode:

during off-road driving (page 355)

when crossing water (page 360)

when towing up or down on steep
gradients
With the LOW RANGE selected, the
engine’s power delivery and the shifting
behavior of the automatic transmission are
adjusted. Furthermore, the ABS, ESP
® and
4-ETS functions especially adapted to
off-road travel are activated.
For information on driving safety systems
during LOW RANGE mode, see “Driving
safety systems” (
page 101).
For more information on Off-road driving,
see “Off-road driving” (
page 355).Gear Ranges
There are two possible settings.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO* start/stop button in
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
iThe vehicle is equipped with permanent
four-wheel drive. Both the front and rear axles
are powered at all times when the vehicle is
being operated.
HIGH
RANGERoad position for all normal
driving situations.
(LOW RANGE mode off)
LOW
RANGEOff-road position for traveling
on rough terrain.
(LOW RANGE mode on)
Also use the off-road position
when driving on-road on steep
gradients, especially when
towing a trailer.
LOW RANGE acts by raising
the engine’s gear ratio. The ve-
hicle travels at roughly third
the speed compared to when
in the HIGH RANGE position,
leading to an increase in the
engine’s drive power.
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