2007 MERCEDES-BENZ GL450 accel

199 Controls in detail
Automatic transmission
Maneuvering
When you maneuver in tight areas,
e.g. when pulling into a parking space:
Control the vehicle speed by gradually
releasing the brakes.
Accelerate gently.
Never abruptly step on the accelerator.
Rocking the vehicle
Rocking the vehicle by shifting between
drive positionD and reverse gearR can
help free a vehicle stuck in mud or snow.
The engine control system of this vehicle
electronically limits shifting between
drive positionD and reverse gearR to
very low speeds, i.e. approximately
5 mph (9 km/h). To shift between drive
positionD and reverse gearR, move the
gear selector lever past the resistance
point up or down.Working on the vehicle
Hill start assist systemOn 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
malfunction
Warning!G
When working on the vehicle, set the
parking brake and shift to park positionP.
Otherwise the vehicle could roll away.
Warning!G
The hill start assist system is not designed
to function as a parking brake and does not
prevent the vehicle from moving when
parked on an incline.
Always set the parking brake in addition to
shifting to park position
P.

202 Controls in detail
Automatic transmission
Upshifting
Briefly press right shift button2.
The transmission will shift to the next
higher gear as permitted by the shift
program. This action simultaneously
extends the gear range of the automat-
ic transmission (
page 200).
Canceling gear range limit
Press and hold right shift button2
until the cipher for the current gear
range disappears from the multifunc-
tion display (
page 200).
The transmission will shift from the
current gear range directly to gear
rangeD.Shifting into optimal gear range
Press and hold left shift button1.
The transmission will automatically
select the gear range suited for optimal
acceleration and deceleration. This will
involve shifting down one or more
gears.Emergency operation (Limp-Home Mode)
If vehicle acceleration becomes less re-
sponsive or sluggish or the transmission
no longer shifts, the transmission is most
likely operating in limp-home (emergency
operation) mode. In this mode only second
gear and reverse gear can be activated.
Stop the vehicle in a safe location.
Shift to park positionP.
Turn off the engine.
Wait at least 10 seconds before
restarting.
Restart the engine.
Shift to drive positionD (for second
gear) or reverse gearR.
Have the transmission checked at an
authorized Mercedes-Benz Light Truck
Center as soon as possible.
iIf you press on the accelerator when the
engine has reached its rpm limit, the transmis-
sion will upshift beyond any gear range limit
selected.

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.

259 Controls in detail
Driving systems
Activating cruise control
You can activate the cruise control when
the vehicle speed is above
20 mph (30 km/h).
In the following cases you cannot activate
the cruise control:

when you brake

when you have set the parking brake

when the automatic transmission is set
to positionP, R, or N

if the ESP® is switched off

if the ESP® has switched off due to a
malfunctionSetting current speed
Accelerate or decelerate to the desired
speed.
Briefly lift the cruise control lever in
direction of arrow1 or depress in
direction of arrow2.
The current speed is set.
Remove your foot from the accelerator
pedal.
The cruise control is activated.
The current set speed appears in the
multifunction display for approximately
5 seconds.Canceling cruise control
There are several ways to cancel the cruise
control:
Step on the brake pedal.
The cruise control is canceled. The last
speed set is stored for later use.
or
Briefly push the cruise control lever in
direction of arrow3 (
page 258).
The cruise control is canceled. The last
speed set is stored for later use.
iThe vehicle speed displayed in the speedom-
eter can briefly vary from the speed setting for
the cruise control system.iOn uphill grades, the cruise control may not
be able to maintain the set speed. Once the
grade eases, the set speed will be resumed.
On downhill grades, the cruise control maintains
the set speed by braking with the vehicle’s
braking system. In addition, on longer downhill
grades the automatic transmission will down-
shift automatically.
iThe last stored set speed is deleted when
the engine is turned off.

260 Controls in detail
Driving systems
Setting a higher speed
You can increase the speed in two ways.Adjustment in 1 mph (Canada: 1 km/h)
increments
Briefly lift the cruise control lever up to
the resistance point in direction of
arrow1 (
page 258).
Release the cruise control lever.
The vehicle speed increases in incre-
ments of 1 mph (Canada: 1km/h).
Adjustment in 5 mph
(Canada: 10 km/h) increments
iThe cruise control switches off
automatically when

you step on the brake pedal

you depress the parking brake pedal
The cruise control switches off automatically and
an acoustic warning will sound when

the vehicle speed is below 20 mph
(30 km/h)

the ESP® is in operation

the ESP® is switched off with the ESP®
switch (
page 107)

the ESP® has switched off due to a
malfunction (
page 441)

you set the automatic transmission toN
while driving
Observe additional messages in the
multifunction display that may appear.
!Setting the automatic transmission toN
while driving cancels the cruise control.
However, the automatic transmission should not
be set toN while driving except to coast when
the vehicle is in danger of skidding (e.g. on icy
roads).
iDepressing the accelerator pedal does not
deactivate the cruise control. After a brief accel-
eration (e.g. for passing), the cruise control will
resume the last set speed.
Warning!G
If you increase the set vehicle speed, keep in
mind that it may take a brief moment until
the vehicle has reached the set speed.
Increase the set vehicle speed to a value
that the prevailing road conditions and legal
speed limits permit. Otherwise, sudden and
unexpected acceleration of the vehicle
could cause an accident and/or serious in-
jury to you and others.
iThe set value is increased in 1 mph
(Canada: 1 km/h) increments each time you lift
the cruise control lever up to the resistance
point.
iThe set value is increased in
5 mph (Canada: 10 km/h) increments each time
you lift the cruise control lever past the
resistance point.

261 Controls in detail
Driving systems
Briefly lift the cruise control lever up
past the resistance point in direction of
arrow1 (
page 258).
Release the cruise control lever.
The vehicle speed increases in incre-
ments of 5 mph (Canada: 10 km/h).
Setting a lower speedYou can reduce the speed in two ways.
Adjustment in 1 mph (Canada: 1 km/h)
increments
Briefly press the cruise control lever
down to the resistance point in direc-
tion of arrow2 (
page 258).
Release the cruise control lever.
The vehicle speed decreases in incre-
ments of 1 mph (Canada: 1 km/h).Adjustment in 5 mph
(Canada: 10 km/h) increments
Briefly press the cruise control lever
down past the resistance point in direc-
tion of arrow2 (
page 258).
Release the cruise control lever.
The vehicle speed decreases in incre-
ments of 5 mph (Canada: 10 km/h).
iThe new speed is set and the vehicle will
accelerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.
Warning!G
If you decrease the set vehicle speed, keep
in mind that it may take a brief moment until
the vehicle has reached the set speed.
Decelerate the set vehicle speed to a value
that the prevailing road conditions and legal
speed limits permit. Otherwise, sudden and
unexpected deceleration of the vehicle
could cause an accident and/or serious in-
jury to you and others.
iWhen you use the cruise control lever to
decelerate, the brake system will automatically
brake the vehicle if the engine’s braking power
does not brake the vehicle sufficiently.
iThe set value is decreased in 1 mph
(Canada: 1 km/h) increments each time you
press the cruise control lever down to the resis-
tance point.
iThe set value is decreased in 5 mph
(Canada: 10 km/h) increments each time you
press the cruise control lever down past the
resistance point.
iThe new speed is set and the vehicle will
decelerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.

262 Controls in detail
Driving systems
Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in di-
rection of arrow4 (
page 258).
The cruise control resumes to the last
set speed, or if no speed is stored, it
will set and store the current speed.
Remove your foot from the accelerator
pedal.
The last set speed appears in the multi-
function display for approximately
5 seconds.
Distronic*
When activated, the Distronic adaptive
cruise control system increases the driving
convenience afforded by the cruise control
while traveling on expressways and other
major roadways.

If the Distronic distance sensor detects
a slower moving vehicle directly ahead,
your vehicle speed will be reduced so
that you follow that vehicle at your
preset following distance.

If there is no vehicle directly ahead of
you, Distronic will function in the same
way as standard cruise control
(
page 257).
Warning!G
The set speed stored in memory should only
be set again if prevailing road conditions
permit. Possible acceleration or decelera-
tion differences arising from returning to the
preset speed could cause an accident
and/or serious injury to you and others.
Warning!G
Distronic is a convenience system. Its speed
adjustment reduction capability is intended
to make cruise control more effective and
usable when traffic speeds vary. It is not
however, intended to, nor does it, replace
the need for extreme care. The responsibili-
ty for the vehicle’s speed, distance to the
preceding vehicle and, most importantly,
brake operation to ensure a safe stopping
distance, always remains with the driver.
Distronic cannot take road and traffic condi-
tions into account.
Complex driving situations are not always
fully recognized by Distronic. This could
result in wrong or missing distance
warnings.

263 Controls in detail
Driving systems
Warning!G
Distronic adaptive cruise control is no
substitute for active driving involvement. It
does not react to pedestrians or on station-
ary objects, nor does it recognize or predict
the lane curvature or the movement of
preceding vehicles.
Distronic can only apply a maximum of 20%
of the vehicle’s braking power.
It is the driver’s responsibility at all times to
be attentive to the road, weather and traffic
conditions. Additionally, the driver must
provide the steering, braking and other
driving inputs necessary to remain in control
of the vehicle.
High-frequency sources such as toll
stations, speed measuring systems etc. can
cause the Distronic system to malfunction.
Warning!G
Distronic requires familiarity with its opera-
tional characteristics. We strongly recom-
mend that you review the following
information carefully before operating the
system.
Warning!G
Distronic cannot take road and traffic condi-
tions into account. Only use Distronic if the
road, weather and traffic conditions make it
advisable to travel at a constant speed.
Warning!G
Use of Distronic can be dangerous on slip-
pery roads. Rapid changes in tire traction
can result in wheel spin and loss of control.
Distronic does not act upon adverse sight
and distance conditions. Do not use
Distronic during conditions of fog, heavy
rain, snow or sleet.
Warning!G
Distronic cannot take weather conditions
into account. Switch off Distronic or do not
switch it on if:

roads are slippery or covered with snow
or ice. The wheels could lose traction
while braking or accelerating, and the
vehicle could skid.

the sensor is dirty or visibility is
diminished due to snow, rain or fog, for
example. The distance control system
functionality could be impaired.
Always pay attention to surrounding traffic
conditions even while Distronic is switched
on. Otherwise, you may not be able to recog-
nize dangerous situations until it is too late.
This could cause an accident in which you
and others could be injured.