MERCEDES-BENZ R350 2008 W251 Owner's Manual

260 Controls in detail
Driving systems
Setting a higher speed
You can increase the set 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 set speed increases in in-
crements of 1 mph (Canada: 1 km/h).
!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 brief acceler-
ation (e.g. for passing), the cruise control will
resume the last speed set.
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
injury to you and others.
iThe set speed value is increased in 1 mph
(Canada: 1 km/h) increments each time you lift
the cruise control lever to the resistance point.

261 Controls in detail
Driving systems
Adjustment in 5 mph
(Canada: 10 km/h) increments
Briefly lift the cruise control lever up
past the resistance point in direction of
arrow1 (
page 258).
Release the cruise control lever.
The vehicle set speed increases in
increments of 5 mph
(Canada: 10 km/h).Setting a lower speed
You can reduce the set 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 set speed decreases in in-
crements of 1 mph (Canada: 1 km/h).
iThe set speed value is increased in
5 mph (Canada: 10 km/h) increments each time
you lift the cruise control lever past the
resistance point.
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.
Decrease 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
injury 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 speed 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.

262 Controls in detail
Driving systems
Adjustment in 5 mph
(Canada: 10 km/h) increments
Briefly press the cruise control lever
down past the resistance point in
direction of arrow2.
Release the cruise control lever.
The vehicle set speed decreases in
increments of 5 mph
(Canada: 10 km/h).Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in
direction 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* (Canada only)
The Distronic is available on the
R5504MATIC only.
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).
iThe set speed 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.
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.

263 Controls in detail
Driving systems
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 responsibility 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.
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.


264 Controls in detail
Driving systems
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.
Warning!G
The “Resume” function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
Warning!G
Close attention to road and traffic condi-
tions is imperative at all times, regardless of
whether or not Distronic is activated.
Use of Distronic can be dangerous on
winding roads or in heavy traffic because
conditions do not allow safe driving at a
continuous speed.
Distronic will not react to stationary objects
in the roadway (e.g. a stopped vehicle in a
traffic jam or a disabled vehicle). Distronic
will also not respond to oncoming vehicles.
Switch off Distronic:

when changing from the left to the right
lane if vehicles are moving more slowly
in the left lane

when entering a turn lane or highway off
ramp

in complex driving situations, such as in
highway construction zones
In these situations, Distronic will continue to
maintain the set speed unless deactivated.
Distronic is designed and intended only to
maintain a set speed and keep a set dis-
tance from moving objects in front of it.


265 Controls in detail
Driving systems
Distronic displays in the speedometer
dial
1Set speed
If Distronic is activated, one or two cruise
control speed segments come on around
the set speed.1Set speed
2Cruise control speed segments
3Speed of the vehicle ahead
If Distronic detects a vehicle directly
ahead, the cruise control speed
segments2, which represents the differ-
ence from the speed of the preceding
vehicle3 to the driver’s selected set
speed1, appear in the speedometer.iThis 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.
Removal, tampering, or altering of the device will
void any warranties, and is not permitted. Do not
tamper with, alter, or use in any non-approved
way.
Any unauthorized modification to this device
could void the user’s authority to operate the
equipment.
iThe vehicle speed displayed on the speed-
ometer can briefly vary from the speed setting
on the Distronic system.

266 Controls in detail
Driving systems
If Distronic calculates that there is a dan-
ger of collision:

The distance warning lampl in the
instrument cluster comes on
(
page 26).

An intermittent warning sounds.
Immediately apply the brake to avoid a
collision.
Under no circumstances should the
driver await the intermittent warning
sound before braking. See the follow-
ing warning note.
The intermittent warning sound ceases
and the distance warning lampl
goes out when the necessary distance
to the vehicle ahead is again estab-
lished.
Warning!G
An intermittent warning sounds and the
distance warning lampl in the instru-
ment cluster is illuminated if the Distronic
system calculates that the distance to the
vehicle ahead and your vehicle’s current
speed indicate that Distronic will not be ca-
pable of slowing the vehicle sufficiently to
maintain the preset following distance,
which creates a danger of a collision.
Immediately brake the vehicle to increase
your distance to the preceding vehicle. The
warning sound is intended as a final caution
in which you should intercede with your own
braking inputs to avoid a potentially danger-
ous situation. Do not wait for the operation
of the warning signal to intercede with your
own braking. This will result in potentially
dangerous emergency braking which will
not always result in an impact being
avoided.
Tailgating increases the risk of an accident.
Warning!G
Distronic brakes your vehicle with a maxi-
mum deceleration of 6.5 ft/s2 (2 m/s2). This
corresponds to about 20% of the maximum
deceleration of your vehicle.
Distronic brakes the vehicle in an effort to
restore the preset distance or to maintain
the set speed.
Keep driver’s foot area clear at all times, in-
cluding the area under the brake pedal. Ob-
jects stored in this area may impair pedal
movement which could interfere with the
braking ability of the Distronic system.
Do not place your foot under the brake pedal
– your foot could become caught.

267 Controls in detail
Driving systems
Distronic menu in the control system
Use the
DISTRONIC menu to display the
current settings for your Distronic system.
The information shown in the multifunction
display depends on whether the Distronic
system is activated or deactivated.
Press buttonè orÿ repeatedly
until one of the following two displays
appears in the multifunction display.Distronic activated
When you turn Distronic on, you will see
the set speed in the multifunction display
for about 5 seconds. When Distronic is
activated, the following display appears in
the multifunction display.
1Distronic activated
2Set vehicle speedDistronic deactivated
When Distronic is deactivated, you will see
the standard Distronic display in the multi-
function display.
1Preceding vehicle, if detected
2Actual distance to the preceding
vehicle
3Preset distance threshold to the
preceding vehicle
4Your vehicle
Cruise control lever
The Distronic system 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.
iFor activating or deactivating the Distronic
system, see “Activating Distronic” (
page 268)
or see “Deactivating Distronic” (
page 271).
For activating or deactivating the Distance warn-
ing function, see “Distance warning function*”
(
page 185).

268 Controls in detail
Driving systems
1Setting current or higher speed
Adjustment in 1 mph increments (to
the resistance point) or 5 mph
increments (past the resistance point)
(Canada: 1 km/h or 10 km/h)
2Setting current or lower speed
Adjustment in 1 mph increments (to
the resistance point) or 5 mph
increments (past the resistance point)
(Canada: 1 km/h or 10 km/h)
3Deactivating Distronic
4Activating Distronic or resuming to last
set speedActivating Distronic
You can activate Distronic when the vehi-
cle speed is between 20 mph (30 km/h)
and 110 mph (180 km/h).
When Distronic is activated the standard
display in the multifunction display will
show a message such as
DISTRONIC 55 MPH.
If Distronic has not been activated after
pressing the cruise control lever, you will
see the message
DISTRONIC Off in the
multifunction display.
In the following cases you cannot activate
Distronic:

up to 2 minutes after starting the
engine

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
malfunction
Setting the 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 (
page 268).
Distronic is activated and the current
speed is set.
The currently set speed appears in the
status indicator of the multifunction
display.
Remove your foot from the accelerator
pedal.

269 Controls in detail
Driving systems
Setting a higher speedYou can increase the set speed in two
ways.
Adjustment in 1 mph (Canada: 1 km/h)
incrementsBriefly lift the cruise control lever up to
the resistance point in direction of
arrow1 (
page 268).
Release the cruise control lever.
The vehicle set speed increases in in-
crements of 1 mph (Canada: 1 km/h).Adjustment in 5 mph
(Canada: 10 km/h) increments
Briefly lift the cruise control lever up
past the resistance point in direction of
arrow1 (
page 268).
Release the cruise control lever.
The vehicle set speed increases in
increments of 5 mph
(Canada: 10 km/h).
iIf you do not take your foot off of the accel-
erator pedal but continue to accelerate past the
set speed, the following message will appear in
the multifunction display:
DISTRONIC Override
The distance to a slower moving vehicle in front
of you will not be set. Your vehicle speed will
then be determined only by the accelerator
pedal position.
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
injury to you and others.
iThe set speed 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 speed value is increased in 5 mph
(Canada: 10 km/h) increments each time you lift
the cruise control lever up past the resistance
point.
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.