140 Controls in detail
Seats
Multicontour seat*
The multicontour seat has an extendable
seat cushion and inflatable air chambers
built into the backrest to provide additional
lumbar and side support.
The seat cushion depth, seat backrest
cushion-height and curvature can be con-
tinuously varied with switches on the in-
side of each front seat base after the
ignition is switched on (
page 41).
1Seat cushion depth
2Backrest side bolsters
3Backrest center
4Backrest bottom
Switch on the ignition (page 42).
Seat cushion depth
Adjust the seat cushion depth to the
length of your upper leg with
switch1.
Backrest contour
Adjust the contour of the seat backrest
to the desired position with
switchæ orç.
Move the backrest support to the bot-
tom with button4 or to the center
with button3.
Backrest side bolsters
Adjust the side bolsters so that they
provide good lateral support using
switch2.
Seat heating*
The switches for front-seat heating are lo-
cated in the center console.
1Seat heating switch, front seats
2Indicator lamps
200 Controls in detail
Automatic transmission
Towing a trailer
If you tow a trailer, note the following
points:
Manually shift to a lower gear range
(
page 200) 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 366).
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 201).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.
Effect
çThe transmission shifts through
second gear only.
Allows the use of engine’s
braking power when driving:
on steep downgrades
in mountainous regions
under extreme operating
conditions
æThe transmission operates in
first gear only.
For maximum use of engine’s
braking effect on very steep or
lengthy downgrades.
300 Controls in detail
Loading
1Key
2Cover cap
3Sticker FRONT (or REAR)
4Screw for clamping claw
5Clamping claw
The front and rear basic cross bars are of
different lengths. Please pay close atten-
tion to stickers3 FRONT and REAR on the
basic cross bars.
Unlock cover cap2 with key1.
Remove cover cap2.
Sticker3 indicating the location,
FRONT or REAR, becomes visible.
Turn screw4 counterclockwise with
the included Allen wrench until
clamping claw5 is wide open.
6Front basic cross bar
7Rear basic cross bar
8Gaps
9Markings
aRoof rails
Place front basic cross bar6 between
markings9 on roof railsa.4Screw for clamping claw
5Clamping claw
aRoof rail
Make sure clamping claw5 lies flush
against the inside of roof raila as
shown in the illustration.
If necessary, adjust clamping width of
basic cross bars (
page 301).
Slightly tighten screw4 on both sides
by turning it clockwise.
iMarkings9 are located on the inside of
each roof rail, indicated by the white lines in the
illustration.
344 Controls in detail
Useful features
Programming tips
If you are having difficulty programming
the integrated remote control, here are
some helpful tips:
Check the frequency of hand-held
remote control5 (typically located on
the reverse side of the remote). The in-
tegrated remote control is compatible
with radio-frequency devices operating
between 280-390 MHz.
Put a new battery in hand-held remote
control5. This will increase the likeli-
hood of the hand-held remote control
sending a faster and more accurate sig-
nal to the integrated remote control.
While performing step 3, hold
hand-held remote control5 at differ-
ent lengths and angles from the signal
transmitter button (2, 3 or4) you
are programming. Attempt varying
angles at the distance of 2 to 5 in
(5 to 12 cm) away or the same angle at
varying distances.
If another hand-held remote control is
available for the same device, try the
programming steps again using that
other hand-held remote control. Make
sure new batteries are in the hand-held
remote control before beginning the
procedure.
Straighten the antenna wire from the
garage door opener assembly. This
may help improve transmitting and/or
receiving signals.
iCertain types of garage door openers are in-
compatible with the integrated remote control. If
you should experience further difficulties with
programming the integrated remote control,
contact an authorized Mercedes-Benz Center, or
call Mercedes-Benz Customer Assistance
Center (in the USA only) at 1-800-FOR-MER-
Cedes, or Customer Service (in Canada) at
1-800-387-0100.
iUSA only:
This device complies with Part 15 of the
FCC Rules. Operation is subject to the following
two conditions:
(1) This device may not cause harmful interfer-
ence, and
(2) this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
iCanada only:
This device complies with RSS-210 of Industry
Canada. Operation is subject to the following
two conditions:
(1) This device may not cause interference, and
(2) this device must accept any interference
received, including interference that may
cause undesired operation of the device.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
355 Operation
Driving instructions
GL 320 CDI, GL 450
Your vehicle is factory equipped with
“H”-rated tires, which have a speed rating
of 130 mph (210 km/h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km/h).
GL 450*
Your vehicle is factory equipped with
“W”-rated tires, which have a speed rating
of 168 mph (270 km/h).
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km/h).Winter driving instructions
The most important rule for slippery or icy
roads is to drive sensibly and to avoid
abrupt acceleration, braking and steering
maneuvers. Do not use the cruise control
system under such conditions.
When the vehicle is in danger of skidding,
shift the automatic transmission to
positionN. Try to keep the vehicle under
control by corrective steering action.
Road salts and chemicals can adversely af-
fect braking efficiency. Increased pedal
force may become necessary to produce
the normal brake effect.
Depressing the brake pedal periodically
when traveling at length on salt-strewn
roads can bring road-salt-impaired braking
efficiency back to normal.
iFor information on speed ratings for winter
tires, see “Winter tires” (
page 420).
For additional general information on tire speed
markings on the tire sidewall, see “Tire speed
rating” (
page 418).
iFor information on driving with snow chains,
see “Snow chains” (
page 421).
Warning!G
On slippery road surfaces, never downshift
in order to obtain braking action. This could
result in drive wheel slip and reduced vehi-
cle control. Your vehicle’s ABS will not pre-
vent this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle
steering is adversely affected by the
Off-road – ABS (
page 104).
360 Operation
Driving instructions
Driving in steep terrain
Slope angle
1 Overhang angle, front
2Overhang angle, rear
Comply with the warnings
(
page 357) and rules for off-road
driving (
page 358).
Driving on embankments, slopes and
other steep inclines should only be
done straight up or downhill, i.e. in the
line of gravity. Maximum vehicle climb-
ing ability is a 100% grade which is
equivalent to a slope angle of
45 degrees. Keep in mind that the
climbing ability of the vehicle depends
on terrain conditions.
Shift automatic transmission to
position1 (
page 200).
Drive slowly.
Avoid excessive engine speeds – drive
with moderate engine speeds
(max. 3 000 rpm).
Utilize the engine’s braking power
when descending a slope, observe the
engine speed (do not overrev the en-
gine). Apply the service brake as need-
ed.
Check the brakes after a lengthy down-
grade drive.Vehicles with air
suspension pack-
age12
Raised level34°28°
Highway29°23°
Vehicles with
enhanced off-road
package*12
Off-road-level 336°30°
Off-road-level 234°28°
Off-road-level 131°25°
Highway29°23°
iFor maximum engine speed, see “Instru-
ment cluster” (
page 26) and see “Engine”
(
page 553).
Warning!G
Never turn the vehicle around on steep
inclines. The vehicle might roll over. If the
vehicle cannot complete the attempted
climb, back it down in reverse gear.
361 Operation
Driving instructions
Traction in steep terrain
The maximum vehicle climbing ability is a
100% grade which is equivalent to a slope
angle of 45 degrees. Keep in mind that the
climbing ability of the vehicle depends on
terrain conditions.
Be easy on the accelerator and watch for
continuous wheel traction when driving in
steep terrain.Driving across a hilltop
Decelerate just ahead of a hilltop (do not
shift automatic transmission to
positionN), to prevent the vehicle from
speeding up too much after climbing a hill.
Use the momentum of the vehicle to drive
across the hilltop.
After climbing a hill, driving in this manner
prevents the vehicle from:
losing ground contact when cresting
hills
losing its forward momentum
speeding up too much after climbing
the hillDriving downhill
Drive slowly.
Do not drive at an angle to the incline.
Steer into the line of gravity and drive
with the front wheels pointing straight
downhill. Otherwise, the vehicle may
slide sideways off the path and roll
over.
Shift automatic transmission to
position1 (
page 200).
On steep inclines, use the Downhill
Speed Regulation (
page 275).
Utilize the engine’s braking power to
reduce vehicle speed.
If this is insufficient, apply the brake
gently. Make sure the vehicle is moving
in the line of gravity.
Check the brakes after a lengthy down-
grade drive.
iThe hill start assist system supports you
when driving uphill.
For more information, see “Hill start assist sys-
tem” (
page 199).
iThe 4-ETS helps greatly when starting out on
a steep incline when the front wheels have then
the tendency to slip due to the weight shifting
towards the rear axle.
The 4-ETS recognizes the situation and limits the
torque for the front wheels by braking them.
Simultaneously the torque for the rear wheels is
increased.
iVehicles with enhanced off-road package*
are equipped with automatic locks for the center
and rear axle differential to improve vehicle
traction.
368 Operation
Driving instructions
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.
Ma ke sur e to l ea ve e nough s la ck i n 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.
Make sure the automatic transmission
is set toP (
page 194).
Set the parking brake for the vehicle
(
page 68).
Start the engine (page 57).
Set the vehicle level to Highway
(
page 281).
Vehicle with ADS*: Set the ADS* to
AUTO or COMFORT (
page 280).
Turn off the engine (page 69).
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 281) or the vehicle level
control system (
page 281) when cou-
pling/decoupling the trailer.
!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.