Page 257 of 522

256 Controls in detailDriving systems
Immediately brake the vehicle 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 red distance warning
lampl goes out when the neces-
sary distance to the vehicle ahead is
again established.
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 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.
Page 258 of 522
257 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 multifunction display depends on
whether Distronic and the distance warn-
ing function are turned on or off.
Press buttonè orÿ repeatedly
until you see one of the following dis-
plays.Distronic deactivated
When Distronic is deactivated you will see
the standard display of Distronic in the
multifunction display.
1Vehicle ahead, if detected
2Actual distance to vehicle ahead
3Preset distance threshold to vehicle
ahead
4Your vehicle
5Symbol for activated distance warning
functionDistronic activated
If you turn Distronic on, you will see the set
speed in the multifunction display for
about 5 seconds. When Distronic is
activated, you will see the following display
in the multifunction display.
1Distronic activated
Page 259 of 522

258 Controls in detailDriving systemsCruise 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.
1Set current or higher speed
2Set current or lower speed
3Deactivate Distronic
4Resume at last set speedActivating Distronic
You can activate Distronic if
you are driving between 20 mph
(30 km/h) and 110 mph (180 km/h)
the ESP
® is activated (
page 100)
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 or depress the cruise control
lever.
The current speed is set.
Remove your foot from the accelerator
pedal.
i
If you do not take your foot off the
accelerator completely, the following message
will appear in the multifunction display:
DISTRONIC
overrideThe distance to a slower moving vehicles in front
of you will not be set. Your vehicle speed will
then be determined only by the accelerator ped-
al position.
Page 260 of 522

259 Controls in detail
Driving systems
Setting a higher speed
Briefly tip the cruise control lever in di-
rection of arrow1 (
page 258) to in-
crease 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 257), and one or
two segments around the stored speed
come on in the speedometer
(
page 255).Setting a lower speed
Briefly tip the cruise control lever in di-
rection of arrow2 (
page 258) to de-
crease 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 257), and one or
two segments around the stored speed
come on in the speedometer
(
page 255).Fine adjustment in 1 mph
(Canada: 1 km/h) increments
Faster
Briefly tip the cruise control lever in di-
rection of arrow4 (
page 258).
i
Depressing the accelerator pedal does not
deactivate Distronic. After brief acceleration
(e.g. for passing), the cruise control will resume
the last speed set.
i
When you use the cruise control lever to de-
celerate, the brakes will be applied to support
deceleration.
In addition, the transmission will automatically
downshift on long downhill grades.
Page 261 of 522

260 Controls in detailDriving systemsSetting to last stored speed
(“Resume” function)
Briefly tip the cruise control lever in di-
rection of arrow4 (
page 258).
Distronic is activated and set to the last
stored speed.
Remove your foot from the accelerator
pedal.Deactivating Distronic
There are several ways to deactivate the
Distronic system:
Briefly tip the cruise control lever in di-
rection of arrow3 (
page 258).
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 20 mph
(30 km/h)
the ESP
® is active (
page 100) or you
deactivate 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.
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 the pre-
set speed could cause an accident and/or
serious injury to you and others.
i
The following message will appear in the
multifunction display for approximately
5seconds:
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 20 mph (30 km/h)
by operation of the system. At that time the
driver must apply the brakes in order to re-
duce vehicle speed further or bring it to a
stop.
Page 262 of 522

261 Controls in detail
Driving systems
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.
The thumbwheel for making the time set-
ting is located on the lower section of the
center console.1Distance warning function on/off
switch
2Indicator 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 smaller 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 will sound if
necessary.
If these warnings are issued, you must
brake manually to maintain a safe distance
and avoid a collision with the vehicle
ahead.
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.
Page 263 of 522

262 Controls in detailDriving systemsWhen pressing the brake pedal, the warn-
ing sound ceases. The warning sound will
also cease when the distance to the vehi-
cle ahead is sufficient again without apply-
ing the brakes. In this case, the distance
warning lamp will also go out.Activating
Press switch1.
Indicator lamp 2 on the switch comes
on. A loudspeaker symbol appears in
the multifunction display (
page 257).
Deactivating
Press switch1.
Indicator lamp 2 on the switch goes
out. No loudspeaker symbol appears in
the multifunction display.Driving with Distronic
This section describes a number of driving
situations where special precaution is re-
quired on the part of the driver. Be pre-
pared to brake in such situations. This will
deactivate the Distronic system.
Warning!
G
If the distance warning lampl in the in-
strument cluster comes on while driving
and/or an intermittent warning sounds, im-
mediate attention on the part of the driver is
required. As required by the traffic situation,
apply the brakes and navigate around a pos-
sible obstacle. However, do not drive by re-
lying on the distance warning function, as
this will result in an emergency braking ap-
plication. Especially depending on road sur-
face conditions and driver reaction, this will
not always enable you to avoid a collision.i
Complex driving situations are not always
fully recognized by Distronic. This could result in
wrong or missing distance warnings.
Warning!
G
Distronic works to maintain the speed se-
lected by the driver unless a moving obsta-
cle proceeding directly ahead of it in the
same travel direction is detected (e.g. fol-
lowing another vehicle ahead of you at a dis-
tance set by Distronic). This means that:
Your vehicle can pass another vehicle
after you change lanes.
While in a sharp turn or if the vehicle in
front is in a sharp turn, Distronic could
lose sight of a vehicle traveling in front
of it, then your vehicle could accelerate
to the previously selected speed.
Page 264 of 522

263 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 Manualappears in the multifunction display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 373).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.
Distronic regulates only the distance be-
tween your vehicle and those directly ahead
of it, but does not register stationary objects
in the road, e.g.:
a stopped vehicle in a traffic jam
a disabled vehicle
an oncoming vehicle
The driver must always be on the alert, ob-
serve all traffic and intercede as required by
steering or braking the vehicle.
Warning!
G
Distronic should not be used in snowy or icy
road conditions.
i
If the message
DISTRONIC
currently unavailable
See Operator’s Manualdisappears during driving and the last speed
stored flashes for approximately 5 seconds, the
dirt (e.g. slush) has dissolved; Distronic works
again.