Page 209 of 456

208 Controls in detailDriving systemsDistronic*
When activated, the Distronic adaptive
cruise control system increases driving
convenience afforded by the cruise control
during travel on expressways and other
major roads.
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 a preset
distance.
If there is no vehicle directly ahead of
you, Distronic will function in the same
way as cruise control (
page 205).
Warning!
G
Distronic adaptive cruise control is no sub-
stitute for active driving involvement. It does
not react to stationary objects, nor does it
recognize or predict the curvature and lane
layout or the movement of vehicles ahead.
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 traffic and road conditions
and to provide the steering, braking and oth-
er driving inputs necessary to retain control
of the vehicle.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. However, it
is not intended to, nor does it, replace the
need for extreme care. The responsibility for
the vehicle speed and the distance to the ve-
hicle ahead, including most importantly
brake operation to assure safe stopping dis-
tance, always rests with the driver.
Distronic cannot take street and traffic con-
ditions into account.
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.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
interference, and
(2) this device must accept any inter-
ference received, including interfer-
ence that may cause undesired
operation.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.
Page 210 of 456

209 Controls in detail
Driving systems
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 interfer-
ence, and
(2) this device must accept any inter-
ference received, including interfer-
ence that may cause undesired
operation of the device.
Any unauthorized modification to this
device could void the user’s authority
to operate the equipment.Warning!
G
Distronic cannot take street and traffic con-
ditions into account. Only use Distronic if
the road, weather and traffic conditions
make it advisable to travel at a steady
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
distance conditions. Do not use Distronic
during conditions of fog and heavy rain,
snow or sleet.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 wind-
ing roads or in heavy traffic because condi-
tions do not allow safe driving at a steady
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.
Warning!
G
The “Resume” function should only be oper-
ated if the driver is fully aware of the previ-
ously set speed and wishes to resume this
particular preset speed.
Page 211 of 456
210 Controls in detailDriving systemsDistronic displays in the speedometer
dialSet speedIf Distronic is activated, one or two seg-
ments come on in the mph scale around
the set speed.
SegmentsIf Distronic detects a vehicle directly
ahead, the segments (representing the dif-
ference) between the speed of the vehicle
ahead and the set speed comes on.
If Distronic calculates that there is a dan-
ger of collision (
page 216):
The distance warning lampl in the
instrument cluster comes on.
An intermittent warning sounds.
Immediately brake the vehicle to avoid
a collision.
Under no circumstances should the
driver await the intermittent warning
sound before braking.
The intermittent warning sound ceases
and the red distance warning
lampl goes out when the neces-
sary distance to the vehicle ahead is
again established.
iThe vehicle speed displayed on the
speedometer can briefly vary from the
speed setting on the Distronic system.
Page 212 of 456

211 Controls in detail
Driving systems
Distronic menu in the control system
In the Distronic menu you see the current
settings for Distronic. What appears in the
multifunction display depends on whether
Distronic and the distance warning func-
tion are turned on or off.
Press buttonè orÿ repeatedly
until you see one of the following dis-
plays.
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
the distance between your vehicle and the
vehicle in front of you. The warning sound is
intended as a final caution that you have not
interceded with your own braking inputs to
avoid a potentially dangerous situation. Do
not wait for the operation of the warning sig-
nal to intercede with your own braking, as
that will result in potentially dangerous
emergency braking which will not always re-
sult in an impact being avoided.
Tailgating increases the risk of an accident.
Warning!
G
Distronic brakes your vehicle with a maxi-
mum of 6.5 ft/s
2 (2 m/s
2). This corre-
sponds to about 20% of the maximum
deceleration ability of your vehicle.
Distronic brakes the vehicle in an effort to
restore the preset distance or to maintain
the speed. The brake pedal is automatically
applied as this happens which results in the
brake pedal moving.
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.
Page 213 of 456
212 Controls in detailDriving systemsDistronic deactivated
If Distronic is deactivated, you can see the
standard display of Distronic in the multi-
function display.
1Vehicle ahead, if detected
2Actual distance to vehicle ahead
3Preset distance threshold to vehicle
ahead
4Symbol for activated distance warning
function
5Your vehicleDistronic activated
If you turn Distronic on, you will see the set
speed in the multifunction display for
about 5 seconds. You then see the follow-
ing display in the multifunction display.
1Distronic activatedCruise 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.
1Sets current or higher speed
2Sets current or lower speed
3Deactivates Distronic
4Resumes at last set speed
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213 Controls in detail
Driving systems
Activating Distronic
You can activate Distronic when
you are driving above 25 mph
(40 km/h)
the ESP
® switched on (
page 82)
If Distronic has not been activated after
pressing the cruise control lever, you will
see the message
---
in the multifunction
display.In the following cases you cannot activate
Distronic:
up to 2 minutes after starting the en-
gine
when you brake
if you have set the parking brake
if the gear selector lever is in
positionP, R or N
if the ESP
® is switched offSetting the current speed
Accelerate or decelerate to the desired
speed.
Briefly lift the cruise control lever in the
direction of arrow1 or depress in the
direction of arrow2.
Distronic is activated and the current
speed is set.
Remove your foot from the accelerator
pedal.
iThe maximum speed you can set is
110 mph (180 km/h).
iIf you do not take your foot off of the
accelerator completely, the following
message will appear in the multifunc-
tion display: DISTRONIC OVERRIDEDistronic will not work to maintain the
distance to a slower moving vehicles in
front of you. Your vehicle speed will
then be determined only by the accel-
erator pedal position.
Page 215 of 456

214 Controls in detailDriving systemsSetting a higher speed
Briefly tip the cruise control lever in the
direction of arrow1 (
page 212) to
decrease vehicle speed in increments
of 5 mph (Canada: 10 km/h).
The new speed is set.
The stored speed is displayed in the
multifunction display for approximately
5 seconds (
page 212), and one or
two segments around the stored speed
come on the speedometer
(
page 210).
Setting a lower speed
Briefly tip the cruise control lever in the
direction of arrow2 (
page 212) to
decrease vehicle speed in increments
of 5 mph (Canada: 10 km/h).The new speed is set.
The stored speed is displayed in the
multifunction display for approximately
5 seconds (
page 212), and one or
two segments around the stored speed
come on the speedometer
(
page 210).
Fine adjustment in 1 mph
(Canada: 1 km/h) increments
Faster
Briefly tip the cruise control lever in the
direction of arrow4 (
page 212).Setting to last stored speed
(“Resume” function)
Briefly tip the cruise control lever in the
direction of arrow4 (
page 212).
Distronic is set to the last stored
speed.
Remove your foot from the accelerator
pedal.
iDepressing the accelerator pedal does
not deactivate Distronic. After brief ac-
celeration (e.g. for passing), the cruise
control resumes the last speed set.
iWhen you use the cruise control lever
to decelerate, the brakes will be ap-
plied to support deceleration.
In addition, the transmission will auto-
matically downshift on long downhill
grades.
Warning!
G
The speed stored in memory should only be
set again if prevailing road conditions per-
mit. Possible acceleration or deceleration
differences arising from returning to preset
speed could cause an accident and/or seri-
ous injury to you and others.
Page 216 of 456

215 Controls in detail
Driving systems
Deactivating Distronic
There are several ways to deactivate the
Distronic system:
Briefly tip the cruise control lever in the
direction of arrow3 (
page 212).
or
Step on the brake pedal.
Distronic will be deactivated. The last
speed set will be stored into memory.Distronic deactivates automatically when:
You set the parking brake.
You drive slower than 22 mph
(35 km/h).
The ESP
® engages (
page 82) or you
switch off the ESP
®.
You move the gear selector lever into
positionN.
A signal will sound. The
DISTRONIC OFF
message appears in the multifunction
display for approximately 5 seconds.Setting the following distance in
Distronic
You can set the specified following dis-
tance for Distronic by varying the time set-
ting between 1.0 and 2.0 seconds. Using
this time setting and the current speed of
your vehicle, Distronic calculates and sets
the required following distance to the vehi-
cle ahead. The set distance will be shown
in the multifunction display field.
iThe following message will appear in
the multifunction display for approxi-
mately 5 seconds:DISTRONIC OFFThe last stored speed is deleted when
you turn off the engine.
Warning!
G
Distronic switches off and releases the
brakes when the vehicle decelerates below
the minimum speed of approximately
22 mph (35 km/h) by operation of the sys-
tem. At that time the driver must apply the
brakes in order to reduce vehicle speed fur-
ther or bring it to a stop.
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.