181 Controls in detail
Driving systems
Distronic displays in the speedometer
dialSet speedIf Distronic is activated, one or two seg-
ments light up around the set speed.
SegmentsIf Distronic detects a vehicle directly
ahead, the segments from the speed of the
vehicle ahead to set speed light up.
If Distronic calculates that there is a dan-
ger of collision
the distance warning lamp
l
in the
instrument cluster lights up red
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. See warning
note on the next page.
The intermittent warning sound ceases
and the red distance warning
lamp
l
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.
182 Controls in detailDriving 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 button
è
or
ÿ
repeatedly
until you see one of the following dis-
plays.
Warning!
G
An intermittent warning sounds and the
distance warning lamp
l
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.
184 Controls in detailDriving systemsActivating Distronic
You can activate Distronic if
you are driving between 25 mph
(40 km/h) and 110 mph (180 km/h)
the ESP is activated (
page 73)
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 183) 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
five seconds (
page 183), and one or
two segments around the stored speed
light up on the speedometer
(
page 181).
iIf you do not take your foot off of the
accelerator completely, the following
message will appear in the multifunc-
tion display: DISTRONIC OVERRIDE
.
Distronic will not work to maintain the
distance to slower moving vehicle in
front of you. 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), the cruise
control will resume the last speed set.
186 Controls in detailDriving systemsDeactivating Distronic
There are several ways to deactivate the
Distronic system:
Briefly tip the cruise control lever in the
direction of arrow3 (
page 183).
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 25 mph
(40 km/h).
The ESP is active (
page 73) or you
deactivate 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 approx. 25 mph
(40 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.
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.
187 Controls in detail
Driving systems
1Distance warning function on / off
switch
2Thumbwheel for setting distance
Increasing distance
Increasing the distance setting tells Dis-
tronic to maintain a greater following dis-
tance to the vehicle ahead.
Turn thumbwheel2 towards
¯
.Decreasing distance
Decreasing the distance setting tells Dis-
tronic to maintain a shorter following dis-
tance to the vehicle ahead.
Turn thumbwheel2 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 lamp
l
in the
instrument cluster lights up
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
l
also extinguishes.
Warning!
G
If the distance warning lamp
l
in the in-
strument cluster lights up 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 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.
188 Controls in detailDriving systemsActivating
Press switch1.
Indicator lamp on the switch lights up.
A loudspeaker symbol appears in the
multifunction display (
page 183).
Deactivating
Press switch1.
Indicator lamp 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.iComplex driving situations are not al-
ways fully recognized by Distronic. This
could result in wrong or missing dis-
tance 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.
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.
189 Controls in detail
Driving systems
The most likely cause for a malfunctioning
system is a dirty sensor (located behind
the hood grill), especially at times of snow
and ice or heavy rain. In such a case, Dis-
tronic will switch off, and the message DISTRONIC - CLEAN SENSOR! SEE OPERA-
TOR'S MAN.
appears in the multifunction
display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic system
sensor” (
page 259).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 - CLEAN
SENSOR! SEE OPER. MANUAL
disappears
during driving and the last speed stored
flashes for approximately five seconds,
the dirt (e.g. slush) has dissolved;
Distronic is again operational.
193 Controls in detail
Driving systems
Normal level (see table)
Speed dependent lowering of vehicle chas-
sis (approximate values):
between 0 mph (0 km/h) and 40 mph
(65 km/h) – none
between 40 mph (65 km/h) and
87 mph (140 km/h) – lowered pro-
gressively by approx. 0.4 in (11 mm).Raised level 1 (see table)
Speed dependent lowering of vehicle chas-
sis (approximate values)
between 0 mph (0 km/h) and 38 mph
(60 km/h) - raised by approx. 0.55 in
(14 mm)
between 38 mph (60 km/h) and
100 mph (160 km/h) - lowered pro-
gressively by approx. 0.55 in (14 mm)
Raised level 2 (see table)
Speed dependent lowering of vehicle chas-
sis (approximate values):
between 0 mph (0 km/h) and 18 mph
(30 km/h) - raised by approx. 0.95 in
(24 mm)
between 18 mph (30 km/h) and
38 mph (60 km/h) - lowered progres-
sively by approx. 0.4 in (10 mm)
between 38 mph (60 km/h) and
100 mph (160 km/h) – lowered pro-
gressively by additional approx. 0.55 in
(14 mm).
Parktronic system* (Parking assist)
iPressing the switch twice in quick suc-
cession will cause the vehicle to imme-
diately raise or lower according to the
starting level.
The selected vehicle level setting re-
mains stored in memory even if the en-
gine is turned off and restarted.
Warning!
G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always rests with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
can be affected by dirty sensors, especially
at times of snow and ice, see “Cleaning the
Parktronic system sensors” (
page 259).
Interference caused by other ultrasonic sig-
nals (e.g. working jackhammers or the air
brakes of trucks) can cause the system to
send erratic indications, and should be tak-
en into consideration.