2008 MERCEDES-BENZ GL320 air conditioning

368 Operation
Driving instructions

Always secure items in the trailer to
prevent load shifts while driving.

When towing a trailer, check occasion-
ally to make sure the load is secure,
and that lighting and trailer brakes (if
so equipped) are functioning properly.

Take into consideration that when tow-
ing a trailer, the handling characteris-
tics are different and less stable from
those when operating the vehicle with-
out a trailer.
It is important to avoid sudden maneu-
vers.

The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
It is more prone to reacting to cross
wind gusts, and requires more sensi-
tive steering input.

If possible, do not brake abruptly, but
rather engage the brake slightly at first
to permit the trailer to activate its
brake. Then increase the braking force.

If the transmission repeatedly shifts
between gears on inclines, manually
shift to a lower gear (select 4, 3, 2 or 1)
(
page 197).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.

On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(
page 278) or LOW RANGE mode*
(
page 201).

When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.

If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.

Extreme care must be exercised since
your vehicle with a trailer will require
additional passing distance ahead than
when driving without a trailer.
Because your vehicle and trailer is
longer than your vehicle alone, you will
also need to go much farther ahead of
the passed vehicle before you can re-
turn to your lane.
!If the trailer should begin to sway, reduce
the vehicle’s speed immediately.
In no case attempt to straighten out the tow
vehicle and trailer by increasing the speed.
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416 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.
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552 Technical data
Layout of poly-V-belt drive
GL 320 CDI
1Coolant pump
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Idler pulley
8Generator (alternator)GL 450, GL 550
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)
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563 Technical data
Fuels, coolants, lubricants
ModelCapacityFuels, coolants, lubricants, etc.
Front wheel hubsAll modelsapprox. 1.5oz (43g) eachHigh temperature roller bearing grease
Brake systemAll models-MB Brake Fluid (DOT 4+)
Cooling systemGL 320 CDIapprox. 10.0 US qt (9.5 l)MB Anticorrosion/Antifreeze
GL 450approx. 10.6 US qt (10.0 l)MB Anticorrosion/Antifreeze
GL 5501approx. 12.7 US qt (12.0 l)MB Anticorrosion/Antifreeze
Fuel Tank
including a reserve ofAll models26.4 US gal (100.0 l)
approx. 3.4 US gal (13.0 l)Gasoline engine:
Premium unleaded gasoline:
Minimum Posted Octane 91
(Avg. of 96 RON/86 MON)
Diesel engine:
ULTRA-LOW SULFUR HIGHWAY DIESEL FUEL
(15 ppm SULFUR MAXIMUM)
Air conditioning systemAll models-R-134a refrigerant and special PAG lubricant oil
(never R-12)
Windshield washer system
and headlamp cleaning
system*All models8.1 US qt (7.7 l)MB Windshield Washer Concentrate2
1Data preliminary.2Use MB Windshield Washer Concentrate “MB SummerFit” and water for temperatures above freezing or MB Windshield Washer Concentrate “MB SummerFit” and
commercially available premixed windshield washer solvent/antifreeze for temperatures below freezing. Follow suggested mixing ratios (page 569).
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564 Technical data
Fuels, coolants, lubricants
Engine oils
Engine oils are specifically tested for their
suitability in our engines and durability for
our service intervals. Therefore, only use
approved engine oils and oil filters
required for vehicles with Maintenance
System. For a listing of approved engine
oils and oil filters, refer to the Factory
Approved Service Products pamphlet
(USA only), or contact an authorized
Mercedes-Benz Light Truck Center.Engine oil additives
Air conditioning refrigerant
R-134a (HFC) refrigerant and special PAG
lubricating oil are used in the air
conditioning system.
Brake fluid
Only brake fluid approved by
Mercedes-Benz is recommended. Any
authorized Mercedes-Benz Light Truck
Center will provide you with additional
information.
!Using engine oils and oil filters of
specification other than those expressly
required for the Maintenance System, or chang-
ing of oil and oil filter at change intervals longer
than those called for by the Maintenance System
will result in engine or emission control system
damage not covered by the Mercedes-Benz
Limited Warranty.
Please follow Maintenance System recommen-
dations for scheduled oil changes. Failure to do
so will result in engine or emission control
system damage not covered by the
Mercedes-Benz Limited Warranty.
!Do not blend oil additives with engine oil.
They may damage the engine.
Damage or malfunctions resulting from blending
oil additives are not covered by the
Mercedes-Benz Limited Warranty.
!Never use R-12 (CFC) or mineral-based
lubricating oil. Otherwise damage to the system
will occur.
Warning!G
During vehicle operation, the boiling point of
the brake fluid is continuously reduced
through the absorption of moisture from the
atmosphere. Under extremely strenuous
operating conditions, this moisture content
can lead to the formation of bubbles in the
system, thus reducing the system’s
efficiency.
Therefore, the brake fluid must be replaced
regularly. Refer to your vehicle’s
Maintenance Booklet for replacement inter-
val.
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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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572 Index
Automatic climate control (3-zone)* 228
Air conditioning refrigerant 563
Air conditioning, Cooling 239, 240
Air distribution, Front 234
Air distribution, Rear 243
Air recirculation mode 237
Air vents*, second-row seats 245
Air vents*, third-row seats 245
Air vents, Front 234
Air volume 235
Control panel, Front 230
Control panel, Rear 241
Deactivating system 232
Defogging 235
Defrosting 235
Maximum cooling, MAXCOOL 237
Rear passenger compartment 241
Rear window defroster 212
Residual engine heat (REST) 241
Using driver-side settings for
all temperature zones 240Automatic headlamp mode 144
Automatic lighting control, Interior
lighting 150
Automatic locking when driving 128
Automatic transmission 56
Accelerator position 195
Emergency operation
(limp-home mode) 200
Gear ranges 197
Gear selector lever 56, 189
Gear selector lever position 192
Gear shifting malfunctions 200
Hill start assist system 196
Kickdown 196
Shifting procedure 192
Starting the engine 56
Steering wheel gearshift control 198
Towing a trailer 197
Transmission fluid level 381
Transmission positions 193
Automatic Transmission Fluid see ATFB
Backrest
Seat 46
Seat, Lumbar support 137
Seat, Multicontour* 138
Backup lamps
Messages in the multifunction
display 477
Replacing bulbs 511
Bar 416
BAS 103
Lamps in instrument cluster 436
Messages in the multifunction
display 451
Batteries, SmartKey
Check lamp 112, 115
Checking battery condition 120
Messages in the multifunction
display 466
Replacing 502
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574 Index
Children in the vehicle 91
Air bags 77, 91
Blocking rear door window
operation 98
Indicator lamp, Front passenger front
air bag 85
Infant and child restraint systems 86,
92
LATCH-type child seat anchors 95
Occupant Classification System
(OCS) 81
Cigarette lighter
(Depending on vehicle
configuration) 323
Climate control 214
Air conditioning refrigerant 563
Air conditioning, Cooling 224, 225
Air distribution, Front 219
Air distribution, rear 227
Air recirculation mode 222
Air vents*, second-row seats 220
Air vents, Front 220
Air volume 220
Control panel*, Rear 226
Control panel, Front 216
Deactivating system 218Defogging 222
Defrosting 221
Rear window defroster 212
Residual engine heat (REST) 225
Clock 27, 174
Cloth upholstery, Cleaning and
care of 434
Cockpit 24
Cockpit Management and Data System
see COMAND System
Cold tire inflation pressure 416
Collapsible wheel chock 494
COMAND System see separate operating
instructions
Combination switch 61, 62, 64, 147
Compass 344
Adjustment 178
Calibration 179
Calling up the compass 344
Control and operation of radio
transmitters 370
Control system 155
Multifunction display 155
Multifunction steering wheel 156
Resetting to factory default 169Control system menus 155
AUDIO 164
DISTRONIC* (Canada only) 167
NAV* 166
Off-road 166
Settings 168
Standard display 162
TEL* 186
Trip computer 184
Vehicle configuration 182
Vehicle status message memory 167
Control system submenus 159, 161, 171
Comfort* 181
Instrument cluster 172, 173
Lighting 175
Time/Date 174
Vehicle 178
Coolant 381, 567
Anticorrosion/antifreeze mixing ratio
and quantity 568
Capacities 562
Checking coolant level 376, 381
Messages in the multifunction
display 470, 472
Temperature 372
Temperature display 162
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