2008 MERCEDES-BENZ GL550 page 164

269 Controls in detail
Driving systems
Setting the following distance in
Distronic
You can set the specified following
distance for Distronic by varying the time
setting between 1.0 and 2.0 seconds. Us-
ing this time setting and the current speed
of your vehicle, Distronic calculates and
sets the required following distance to the
preceding vehicle. The set distance will be
shown in the multifunction display
(
page 265).
The distance setting switch for the time
setting is located on the cruise control le-
ver on the left-hand side of the steering
column.
iThe Distronic switches off automatically
when

you step on the brake pedal

you depress the parking brake pedal
In this case, the Distronic speed segments in the
speedometer (
page 263) will go out.

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

the ESP® is in operation

the ESP® is switched off with the ESP®
switch (
page 105)

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

you set the automatic transmission toN
while driving
The Distronic speed segments in the
speedometer (
page 263) will go out and an
acoustic warning will sound.
Warning!G
Distronic switches off and releases the
brakes when the vehicle decelerates below
the minimum speed of 20 mph (30 km/h)
by operation of the system. At that time the
driver must apply the brakes in order to
reduce vehicle speed further or bring it to a
stop.
!Setting the automatic transmission toN
while driving cancels the Distronic. 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 Distronic. After a brief accelera-
tion (e.g. for passing), the Distronic will resume
the last set speed.
Warning!G
It is up to the driver to exercise discretion to
select the appropriate setting given road
conditions, traffic, driver’s preferred driving
style and applicable laws and driving recom-
mendations for safe following distance.
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271 Controls in detail
Driving systems
The most likely cause for a malfunctioning
system is a dirty sensor (located behind
the hood grille), especially at times of snow
and ice or heavy rain. In such a case,
Distronic will switch off, and the message
DISTRONIC Currently Unavailable – See
Operator’s Manual
appears in the multi-
function display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 430).Turns and bends
In turns or bends, Distronic may not detect
a moving vehicle in front, or it may detect
one too soon. This may cause your vehicle
to brake late or unexpectedly.Offset driving
A vehicle traveling in your lane but offset
from your direct line of travel may not be
detected by Distronic. There will be insuffi-
cient distance to the vehicle ahead.
iIf the message DISTRONIC Available
Again
appears during driving the dirt (e.g.
slush) has dissolved; Distronic works again, if
you reactivate it (
page 266).
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273 Controls in detail
Driving systems
Switch on the distance warning
function in the control system
(
page 183).
Downhill Speed Regulation (DSR)For more information, see “Off-road driv-
ing” (
page 355).
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 183). 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 183), 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.
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274 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 183). 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 265). 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.
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275 Controls in detail
Driving systems
Switching Downhill Speed Regulation on
Press DSR switch1 (page 274).
The indicator lamp2 comes on.
The message
DSR and the set speed ap-
pear in the multifunction display.
For information on how to program the set
speed while driving, see “Adjusting Down-
hill Speed Regulation speed with DSR
switched on” (
page 276).Switching Downhill Speed Regulation off
Press DSR switch1 (page 274).
The indicator lamp2 goes out.
The message
DSR Off appears in the
multifunction display.
Warning!G
If the accelerator pedal is depressed while
the Downhill Speed Regulation is activated,
the vehicle can drive faster than the pro-
grammed set speed. You should therefore
drive downhill with particular caution as it
could otherwise lead to an accident and/or
serious injury to you or others. Keep in mind
that as soon as you remove the foot from
the accelerator pedal with the DSR switched
on, the DSR will start regulating the vehicle’s
speed including use of brakes if required.
Depending on the programmed set speed,
actual vehicle speed and gradient, the DSR
can cause the vehicle to slow down rapidly.
Sudden and unexpected deceleration can
result in loss of vehicle control, causing an
accident and/or serious personal injury to
you and others.
iThe DSR can only be switched on if the vehi-
cle speed is below 18 mph (Canada: 30 km/h).
iIf the DSR is switched on at a speed above
18 mph (Canada: 30 km/h), the message
DSR
Max. Speed 18 mph
(Canada: 30 km/h) ap-
pears in the multifunction display.
iAt a speed above approximately 21 mph
(Canada approximately: 35 km/h), the DSR is
automatically switched off. The message
DSR
Off
appears in the multifunction display and an
acoustic signal sounds. For information on how
to switch DSR on again, see “Switching Downhill
Speed Regulation on” (
page 275).
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276 Controls in detail
Driving systems
Adjusting Downhill Speed Regulation
speed with DSR switched on
With the DSR switched on (
page 274),
the speed setting can be changed using
the cruise control lever.
The cruise control lever is the uppermost
lever on the left-hand side of the steering
column.
Cruise control lever
1Increase set speed
2Reduce set speed
You can change the set speed between
3 - 10 mph (Canada: 4 - 18 km/h).You can increase or reduce the set speed
in two ways.
Adjustment in 1 mph (Canada: 1 km/h)
increments
Increase set speed:
Briefly lift the cruise control lever up to
the resistance point in direction of
arrow1 (
page 276).
Release the cruise control lever.
The vehicle speed increases in incre-
ments of 1 mph (Canada: 1 km/h).Reduce set speed:
Briefly press the cruise control lever
down to the resistance point in direc-
tion of arrow2 (
page 276).
Release the cruise control lever.
The vehicle speed decreases in incre-
ments of 1 mph (Canada: 1 km/h).
Each time the set speed is changed,
DSR will appear in the multifunction dis-
play and the changed set speed is
shown.
iThe set value is increased or decreased in
1 mph (Canada: 1 km/h) increments each time
you lift or depress the cruise control lever to the
resistance point.
iThe set speed is canceled when DSR is
switched off. If DSR is switched on again, DSR
will use the programmed default speed
(
page 183).
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277 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 276).
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 276).
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 360)

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 183).
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278 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 278).
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 program
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 278)

Vehicle level control (page 279)
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.
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