2007 MERCEDES-BENZ GL450 off-road

207 Controls in detail
Differential locks*
at the same speed, independent of the in-
dividual torque. Please be aware that en-
gaging the differential locks will
significantly reduce the steering ability of
the vehicle.
For your safety and the safety of others
and to prevent damage to the vehicle, the
differential locks must not be engaged
when driving on paved roads. It is impor-
tant to understand that during
on-road/paved driving, differentials are
absolutely necessary for providing the es-
sential control and steering ability of the
vehicle. The differential locks, therefore,
must not be engaged when driving on
paved roads and should only be used to
the extent necessary to negotiate off-road
conditions which cannot be handled by the
systems (automatic 4-ETS, the ESP
®, man-
ual switch position “LOW” of transfer case)
this vehicle comes equipped with.
Switching differential locks*The rotary switch for the differential locks
is located on the upper part of the center
console.
You can select between three locking
modes.
1Rotatable outer adjustment ring with
indicator lamp
2AUTO mode: center differential is auto-
matically locked
3Center differential is completely locked
4Center and rear axle differential are
completely locked
!If the differential locks are engaged, accel-
erate gently when setting the vehicle in motion.
To avoid damage to the transmission, the vehicle
may only be operated on a dynamometer (single
axle dynamometer) if

the axle not being driven is jacked up
or

the associated propeller shaft is disconnect-
ed.

208 Controls in detail
Differential locks*
AUTO mode
The AUTO mode is adequate for most driv-
ing situations since the center differential
is locked and released as required.
Start the engine (page 42).
The center differential locks is in AUTO
mode. The indicator lamp on the
adjustment ring1 above
symbolU2 is on.Center and rear axle differential locksThe differential locks should only be
engaged manually if traction is insufficient
in AUTO mode.
The differential locks can be engaged in
the sequence3, 4 (
page 207) up to a
speed of 19 mph (30 km/h).
Engaging differential locks:

for off-road driving

for driving through water

when driving on deep snow and icy or
fouled surfaces
iAt speeds up to 19 mph (30 km/h), it is
possible to manually lock the differential locks
for driving on rough terrain.
Warning!G
Never drive on a paved surface with the
center and rear axle differential locks
manually engaged. Ability to steer the
vehicle is greatly reduced when the differen-
tial locks are manually engaged, increasing
the risk of an accident.
For safety reasons, the locks are automati-
cally released at a vehicle speed above
31 mph (50 km/h). Nevertheless, you
should only manually lock the differential if
absolutely necessary because engaged
locks will restrict the vehicle drive train
while cornering and cause the vehicle to
chatter. This could cause you to lose control
of the vehicle and cause an accident.
!The differential locks must not be engaged
manually when towing the vehicle or spinning the
wheels.

257 Controls in detail
Driving systems
Driving systems
The driving systems of your vehicle are
described on the following pages:

Cruise control (page 257) and
Distronic* (
page 262), with which
the vehicle can maintain a preset
speed.

Distance warning function*
(
page 274) is only available with
Distronic*, which warns of stationary
obstacle or slower moving vehicles that
you are closing in on too quickly.

Downhill Speed Regulation (DSR)
(
page 275), which supports you
when you are driving downhill.

Off-road driving program (page 279)
(vehicles without enhanced off-road
package*), which supports you when
you are driving off-road.

Air suspension package
There are two components available.

Vehicle level control (page 281),
which controls the vehicle level.

Adaptive Damping System (ADS)*
(
page 280), which adjusts the
vehicle suspension characteristics.

Parktronic* (page 290) and rear view
camera* (
page 295), which serve as
a parking aid.
For information on the ABS, BAS, EBP,
ESP
®, and 4-ETS, see “Driving safety sys-
tems” (
page 103).
Cruise control
The cruise control automatically maintains
the speed you set for your vehicle.
The use of cruise control is recommended
for driving at a constant speed for extend-
ed periods of time. You can set or resume
cruise control at any speed above
20 mph (30 km/h).
The cruise control function is operated by
means of the cruise control lever.
The cruise control lever is the uppermost
lever on the left-hand side of the steering
column (
page 24).
iThe cruise control should not be activated
during off-road driving.

275 Controls in detail
Driving systems
Switch on the distance warning
function in the control system
(
page 186).
Downhill Speed Regulation (DSR)For more information, see “Off-road driv-
ing” (
page 357).
The DSR is an aid for driving downhill. DSR
regulates your vehicle’s speed when driv-
ing downhill to the value set in the control
system (
page 186). The steeper the
downhill gradient is, the greater the brake
application. On flat road surfaces, DSR
brakes only slightly or not at all.
DSR regulates the vehicle’s speed in auto-
matic transmission positionsD, orR.
You can drive slower or faster than the set
speed at any time by braking the vehicle or
depressing the accelerator pedal.
Warning!G
If the distance warning lampl in the in-
strument cluster comes on while driving
and/or an intermittent warning sounds,
immediate attention on the part of the driver
is required. As required by the traffic
situation, apply the brakes and navigate
around a possible obstacle. However, do not
drive by relying on the distance warning
function, as this will result in an emergency
braking application. This will not always
enable you to avoid a collision, especially
when traveling on varying road surface
conditions and with varying driver reaction.
Complex driving situations are not always
fully recognized by the distance warning
function. This could result in wrong or miss-
ing distance warnings.Warning!G
Downhill Speed Regulation is a convenience
system designed to assist the driver during
vehicle operation. The system must be set
to be appropriate for the topographical and
weather conditions encountered which can
change quickly. The driver is and must
remain at all times responsible for the vehi-
cle speed and for safe brake operation.
Depending on the programmed speed
(
page 186), actual vehicle speed and gra-
dient, switching on the DSR while driving
can cause the vehicle to slow down rapidly
and you may hear a sound which is caused
by the activation of the vehicle’s brake sys-
tem through the DSR. Sudden and unex-
pected deceleration can result in loss of
vehicle control, causing an accident and/or
serious personal injury to you and others.
Do not switch on the DSR in a circumstance
where rapid deceleration could result in a
loss of vehicle control.
iIn addition, make use of the engine’s braking
effect by shifting the automatic transmission
into a lower gear.

276 Controls in detail
Driving systems
Switching the Downhill Speed
Regulation on/off
The switch is located on the upper part of
the center console.
Vehicles without enhanced off-road
package*
1DSR on/off
2Indicator lamp
Vehicles with enhanced off-road package*
1DSR on/off
2Indicator lamp
iWhenever DSR is switched on, DSR will use
the programmed default speed to regulate the
vehicle’s speed. The default speed programmed
at the factory is 4 mph (Canada: 6 km / h). The
default speed can be reprogrammed using the
control system (
page 186). The next time DSR
is switched on, DSR will use the newly pro-
grammed default speed to regulate the vehicle’s
speed.
Once DSR is switched on, you can adjust the set
speed using the cruise control lever
(
page 267). Keep in mind that adjusting the
set speed using the cruise control lever with DSR
switched on will not change the programmed
default speed. If DSR is switched off and then
switched on again, DSR will use the programmed
default speed.
Depending on the road surface and level of
downhill grade, the DSR may not be able to
maintain the set speed. To maintain the set
speed, apply the brakes if necessary.

279 Controls in detail
Driving systems
Adjustment in 5 mph
(Canada: 10 km/h) increments
Increase set speed:
Briefly lift the cruise control lever up
past the resistance point in direction of
arrow1 (
page 278).
Release the cruise control lever.
The vehicle speed increases in incre-
ments of 5 mph (Canada: 10 km/h).
Reduce set speed:
Briefly press the cruise control lever
down past the resistance point in direc-
tion of arrow2 (
page 278).
Release the cruise control lever.
The vehicle speed decreases in incre-
ments of 5 mph (Canada: 10 km/h).
Each time the set speed is changed,
DSR will appear in the multifunction dis-
play and the newly set speed is shown.Off-road driving program (Vehicles
without enhanced off-road package*)
The off-road driving program is designed to
assist the driver when driving off-road in
terrain and crossing water. The off-road
driving program adjusts the engine power
and shifting of the automatic transmission
to be more suitable for the off-road use of
the vehicle. In addition, the ABS, ESP
®, and
4-ETS designed for off-road use are
automatically activated.
In the following situations you should
switch to the off-road driving program:

during off-road driving

when crossing water (page 362)

when towing up or down on steep
gradients
iThe set value is increased or decreased in
5 mph (Canada: 10 km/h) increments each time
you lift or depress the cruise control lever past
the resistance point.
iThe new speed is set and the vehicle will
accelerate or decelerate. Keep in mind that it
may take a brief moment until the vehicle has
reached the new set speed.
iThe set speed is canceled when DSR is
switched off. If DSR is switched on again, DSR
will use the programmed default speed
(
page 186).

280 Controls in detail
Driving systems
The switch is located on the upper part of
the center console.
1Switch for off-road driving program
2Indicator lampSwitching Off-road driving program on
Press switch1 (page 280).
Indicator lamp2 comes on. The
symboly appears in the lower
multifunction display.
Switching Off-road driving program off
Press switch1 again.
Indicator lamp2 goes out. The
symboly disappears.
Air suspension package
Your vehicle is factory equipped with
vehicle level control which regulates the
ride height of the vehicle. The Adaptive
Damping System (ADS)* optimizes your
vehicle’s suspension tuning.

Suspension tuning: Adaptive Damping
System (ADS)* (
page 280)

Vehicle level control (page 281)
Adaptive Damping System (ADS)*
The fine tuning of the damping and suspen-
sion is dependent on:

your driving style

road surface conditions

your personal ADS settings

your personal vehicle level settings
The ADS switch is located on the upper
part of the center console.

281 Controls in detail
Driving systems
Vehicles without enhanced off-road
package*
Vehicles with enhanced off-road package*
1ADS switch
2Indicator lamp for SPORT setting
3Indicator lamp for COMF settingThe following settings are available:

AUTO (for normal driving situations)
Indicator lamps2 and3 are off.

SPORT (for sporty driving)
Indicator lamp2 comes on.
With the ADS SPORT setting, the vehi-
cle is lowered approximately 0.6 in
(15 mm).

COMF (for comfort driving)
Indicator lamp3 comes on.
Start the engine (page 41).
Press ADS switch1 repeatedly until
the desired suspension tuning is
reached.
Vehicle level control
The vehicle level control automatically
regulates the ride height to

reduce fuel consumption

improve driving stability by lowering
the center of gravity
The vehicle automatically regulates its ride
height based on the set vehicle height and
the current speed:

As your driving speed increases, the ve-
hicle is lowered by increments until it
reaches high-speed level.
Vehicles with ADS*:

If you are driving with the ADS set-
ting COMF or AUTO, the vehicle is
raised back to highway level as your
driving speed decreases.

You can select the high-speed level
via the ADS setting SPORT. In ADS
Sport, the vehicle is lowered direct-
ly to high-speed level as your driv-
ing speed increases.
iThe setting is stored when you turn off the
engine.