211 Controls in detail
Driving systems
Driving systems
The following driving systems are ex-
plained on the following pages:
Cruise control and Distronic*, with
which the vehicle can maintain a preset
speed
Airmatic* adjusts the vehicle suspen-
sion characteristics automatically and
controls the vehicle level
Parktronic system*, which assists the
driver during parking maneuvers
The BAS, ABS, ESP and SBC are described
in the “Safety and Security” section
(
page 74).
Cruise control
The cruise control automatically maintains
the speed you set for your vehicle.
Use of cruise control is recommended for
driving at a constant speed for extended
periods of time. You can set any speed
over 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 found on the left-hand side of the
steering column (
page 20).
Warning!
G
Cruise control is a convenience system de-
signed to assist the driver during vehicle op-
eration. The driver is and must always
remain responsible for the vehicle speed
and for safe brake operation.
Only use cruise control if the road, traffic
and weather conditions make it advisable to
travel at a steady speed.
The use of cruise control can be danger-
ous on winding roads or in heavy traffic
because conditions do not allow safe
driving at a steady speed.
The use of cruise control can be danger-
ous on slippery roads. Rapid changes in
tire traction can result in wheel spin and
loss of control.
Deactivate cruise control when driving
in fog.
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.
214 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 218).
Warning!
G
Distronic adaptive cruise control is no sub-
stitute for active driving involvement. It does
not react to stationary objects, nor recog-
nize 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.iFor operation in the USA only: This de-
vice complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
this device may not cause harmful
interference, and
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.
215 Controls in detail
Driving systems
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.
217 Controls in detail
Driving systems
Distronic menu in the control system
In the Distronic menu you can read the cur-
rent settings for Distronic. What appears in
the display depends on whether Distronic
and the distance warning function 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
DTR warning lamp in the instrument cluster
is illuminated if the Distronic system calcu-
lates that the distance to the vehicle ahead
and your vehicle’s current speed indicate
that Distronic will not be capable of slowing
the vehicle sufficiently to maintain the pre-
set following distance, which creates a dan-
ger of a collision.
Immediately brake the vehicle to increase
the distance to the vehicle in front of you.
The warning sound is intended as a final cau-
tion that you have not interceded with your
own braking inputs to avoid a potentially
dangerous situation. Do not wait for the op-
eration of the warning signal to intercede
with your own braking, as that will result in
potentially dangerous emergency braking
which will not always result in an impact be-
ing avoided.
Tailgating increases the risk of an accident.
Warning!
G
Distronic brakes your vehicle with a maxi-
mum deceleration of 6.5 ft / s
2 (2 m / s
2).
This corresponds to about 20% of the maxi-
mum 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.
219 Controls in detail
Driving systems
Activating Distronic
You can activate Distronic if:
you are driving between 25 mph
(40km/h) and 110mph (180km/h)
the ESP is activated (
page 76)
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 two 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 or depress the cruise control
lever.
Distronic is activated and the current
speed is set.
Remove your foot from the accelerator
pedal.Setting a higher speed
Briefly tip the cruise control lever in the
direction of arrow1 (
page 218) to
increase 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
five seconds (
page 218), and one or
two segments around the stored speed
come on on the speedometer
(
page 216).
iIf you do not take your foot off of the
accelerator completely, the following
message will appear in the multifunc-
tion display: Distronic override
. The distance to a
slower moving vehicles in front of you
will not be set. Your vehicle speed will
then be determined only by the accel-
erator pedal position.
iDepressing the accelerator pedal does
not deactivate Distronic. After brief ac-
celeration (e.g. for passing), cruise con-
trol will resume the last speed set.
221 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 218).
or
Step on the brake pedal.
Distronic will be deactivated. The last
speed set will be stored in memory.Distronic deactivates automatically when:
you set the parking brake
you drive slower than 25 mph
(40 km / h)
the ESP is active (
page 76) or you de-
activate the ESP
you move the transmission selector le-
ver into positionN
A signal will sound. The
Distronic off
message appears in the multifunction
display for approximately five 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.
The thumbwheel for making the time set-
ting is located on the lower section of the
center console.
iThe following message will appear in
the multifunction display for approxi-
mately five seconds:
Distronic off
.
The 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
25 mph (40 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.
222 Controls in detailDriving systems1Distance warning function on / off
switch
2Control lamp
3Thumbwheel for setting distance
Increasing distance
Increasing the distance setting tells
Distronic to maintain a greater following
distance to the vehicle ahead.
Turn thumbwheel3 towards¯.Decreasing distance
Decreasing the distance setting tells
Distronic to maintain a shorter following
distance to the vehicle ahead.
Turn thumbwheel3 towards®.
Distance warning function
When Distronic is deactivated, this func-
tion will continue to warn you when recog-
nizing a stationary obstacle or a slower
vehicle moving in the vehicle’s path and
the danger of a collision exists:
The distance warning lampl in the
instrument cluster comes on.
An intermittent warning sounds.
If these warnings are issued, you must
brake manually to maintain a safe distance
and avoid a collision with the vehicle
ahead.
When pressing the brake pedal, the warn-
ing sound stops. The warning sound also
stops when the distance to the vehicle ahead is sufficient again without applying
the brake pedal. In this case the distance
warning lamp also extinguishes.
Warning!
G
If the DTR warning lampl in the instru-
ment cluster comes on while driving and / or
an intermittent warning sounds, immediate
attention on the part of the driver is re-
quired.
As required by the traffic situation, apply the
brakes and navigate around a possible ob-
stacle. However, do not drive by relying on
the distance warning function, as this will re-
sult in an emergency braking application.
Especially depending on road surface condi-
tions and driver reaction, this will not always
enable you to avoid a collision.iComplex driving situations are not al-
ways fully recognized by Distronic. This
could result in wrong or missing dis-
tance warnings.
224 Controls in detailDriving systemsThe 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 Currently unavailable
see oper. manual
appears in the multifunction display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic system
sensor” (
page 305).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.
iIf the message “Distronic - clean sen-
sor!” See oper. manual disappears dur-
ing driving and the last speed stored
flashes for approximately five seconds,
the dirt (e.g. slush) has dissolved;
Distronic works again.