410 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 (
page 406).
Release the cruise control lever.
The vehicle speed decreases in incre-
ments 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 406).
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, and the corresponding
speedometer segments from the se-
lected speed to the vehicle maximum
speed are illuminated.
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 re-
sistance point.
iThe new speed is set and the vehicle will de-
celerate. 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.
iThe last stored set speed is deleted when
the engine is turned off.
412 Controls in detail
Driving systems
Warning!G
DISTRONIC Plus adaptive cruise control is
no substitute for active driving involvement.
It does not react to pedestrians or stationary
objects, nor does it recognize or predict the
curvature and lane layout or the movement
of vehicles ahead. DISTRONIC Plus can only
apply a maximum of 40% of the vehicle’s
braking power.
DISTRONIC Plus may not detect narrow ve-
hicles possibly driving in front of you, such
as motorcycles and vehicles driving in an
offset formation.
It is the driver’s responsibility at all times to
be attentive to road, weather and traffic con-
ditions and to provide the steering, braking
and other driving inputs necessary to retain
control of the vehicle.
High-frequency sources such as toll sta-
tions, speed measuring systems etc. can
cause the DISTRONIC Plus system to tem-
porarily cease functioning.
Warning!G
DISTRONIC Plus requires familiarity with its
operational characteristics. We strongly rec-
ommend that you review the following infor-
mation carefully before operating the
system.
Warning!G
DISTRONIC Plus cannot take street and traf-
fic conditions into account. Only use
DISTRONIC Plus if the road, weather and
traffic conditions make it advisable to travel
at a steady speed.
Warning!G
Use of DISTRONIC Plus can be dangerous
on slippery roads. Rapid changes in tire trac-
tion can result in wheel spin and loss of con-
trol.
DISTRONIC Plus does not act upon adverse
sight distance conditions. Do not use
DISTRONIC Plus during conditions of fog
and heavy rain, snow or sleet.
Warning!G
DISTRONIC Plus cannot take weather condi-
tions into account. Switch off
DISTRONIC Plus or do not turn 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. The
distance control could be impaired.
Always pay attention to traffic conditions
even while DISTRONIC Plus is switched on.
Otherwise, you may not be able to recognize
dangerous situations until it is too late and
could cause an accident resulting in person-
al or fatal injury to you or others.
413 Controls in detail
Driving systems
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.
Warning!G
Close attention to road and traffic condi-
tions is imperative at all times, regardless of
whether or not DISTRONIC Plus is activated.
Use of DISTRONIC Plus can be dangerous
on winding roads as conditions do not allow
safe driving at a steady speed.
DISTRONIC Plus may not react to stationary
objects in the roadway (e.g. a stopped vehi-
cle in a traffic jam or a disabled vehicle).
DISTRONIC Plus will also not respond to on-
coming vehicles.
Switch off DISTRONIC Plus:
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 Plus will
continue to maintain the set speed unless
deactivated.
DISTRONIC Plus is designed and intended
only to maintain a set speed and keep a set
distance from moving objects in front of it.
iDo not use DISTRONIC Plus if you are driv-
ing on a road with steep uphill or downhill slopes.
iDue to its radar-emitting nature DISTRONIC
Plus may have an appearance similar to a radar
detector to law enforcement officials. You may
want to refer to this section of your Operator’s
Manual when asked.
iUSA only:
This device has been approved by the FCC as a
“Vehicular Radar System”. The radar sensor is
intended for use in an automotive radar system
only. Removal, tampering, or altering of the de-
vice will void any warranties, and is not permitted
by the FCC. 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.
415 Controls in detail
Driving systems
Warning!G
An intermittent warning sounds and the dis-
tance warning lampl in the instrument
cluster is illuminated if the DISTRONIC Plus
system calculates that the distance to the
vehicle ahead and your vehicle’s current
speed indicate that DISTRONIC Plus will not
be capable 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
that you have not interceded 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 avoid-
ed.
Tailgating increases the risk of an accident.
Warning!G
DISTRONIC Plus brakes your vehicle with a
maximum of 13 ft/s2. This corresponds to
about 40% of the maximum deceleration of
your vehicle.
You must also apply the brakes yourself to
avoid a collision. DISTRONIC Plus brakes
the vehicle in an effort to restore the preset
distance or to maintain the set 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 Plus
system.
Do not place your foot under the brake pedal
– your foot could become caught.
Warning!G
If you do not receive visual or acoustic warn-
ing signals during a critical traffic situation,
DISTRONIC Plus has either not recognized
the collision risk, has been deactivated, or is
malfunctioning.
Remember, whether or not DISTRONIC Plus
is operating, it is ultimately always the driv-
ers responsibility to apply the brakes in or-
der to control the vehicle and avoid a
collision.
418 Controls in detail
Driving systems
In the following cases you cannot activate
DISTRONIC Plus:
up to 2 minutes after starting the en-
gine
if the engine is switched off
if you step on the brake pedal while
driving
the vehicle is secured with the elec-
tronic parking brake
if the gear selector lever is in
positionP, R, or N
if ESP® is switched off
if the hood is open
if the driver’s door is open and the driv-
er has not fastened his or her seat belt
if the radar sensors are switched off
(
page 272).Switching on while driving
Tap DISTRONIC Plus lever up1 or
down2 until desired speed is set.
DISTRONIC Plus is switched on.
or
Pull DISTRONIC Plus lever briefly in di-
rection of arrow4 to call up speed
last set (
page 423).
DISTRONIC Plus is switched on.
Take your foot off the accelerator ped-
al.
Your vehicle adapts its speed to the ve-
hicle ahead, observing the set speed as
a maximum value.
iUnder 20 mph (30 km/h), you can only
switch on DISTRONIC Plus if the vehicle ahead of
you has been detected and is shown on the mul-
tifunction display. If you no longer see the vehi-
cle in front of you on the multifunction display
and if it is no longer detected because it has
changed lanes, for example, DISTRONIC Plus
switches off and you will hear a signal.
iIf you do not completely lift your foot off the
accelerator pedal, the message
“DISTRONIC PLUS override” appears on the mul-
tifunction display. The distance to a slower-driv-
ing vehicle will not be set. You will drive at the
speed you dictate by pressing the accelerator
pedal.
419 Controls in detail
Driving systems
Switching on when approaching a
stationary vehicle
If the vehicle in front of you is stationary,
you can only switch on DISTRONIC Plus if
your vehicle is also at a standstill.
Tap DISTRONIC Plus lever up1 or
down2 until desired speed is set.
DISTRONIC Plus is switched on.
or
Pull DISTRONIC Plus lever briefly in di-
rection of arrow4 to call up speed
last set (
page 423).
DISTRONIC Plus is switched on.Starting off
When the vehicle in front of you starts off:
Remove your foot from the brake
pedal.
Pull DISTRONIC Plus lever briefly in di-
rection of arrow4.
or
Briefly step on the accelerator pedal.
Your vehicle starts off and adapts its speed
to the vehicle in front of you.Driving
If no vehicle is driving ahead of you,
DISTRONIC Plus functions like the cruise
control (
page 405).
When DISTRONIC Plus detects that the ve-
hicle in front of you is driving more slowly,
it brakes the vehicle in order to keep the
distance specified by you.
When DISTRONIC Plus detects that the ve-
hicle in front of you is driving faster, the ve-
hicle accelerates up to the set speed.
iIt is helpful to switch on the DISTRONIC Plus
display in the instrument cluster (
page 416)
since you can only switch on DISTRONIC Plus un-
d e r a s p e e d o f 2 0 m p h ( 3 0 k m / h ) w h e n a v e h i c l e
has been detected in front of you.
iYou can adjust the set speed using the
DISTRONIC Plus lever and the target distance
using the distance setting switch on the
DISTRONIC Plus lever (
page 425).
iIf DISTRONIC Plus is switched off,
PRE-SAFE® Brake* (page 73) will warn of an
impending collision if this function has been
activated with the instrument cluster control
system (
page 268).
Warning!G
When you step on the brake pedal, you
switch off DISTRONIC Plus except when the
vehicle is at a standstill. DISTRONIC Plus will
no longer brake your vehicle. You are always
responsible for maintaining a distance from
other vehicles, observing road speeds and
braking well in advance.
424 Controls in detail
Driving systems
DISTRONIC Plus deactivates automatically
when:
the vehicle is secured with the elec-
tronic parking brake
the vehicle speed is below 20 mph
(30 km/h) and no preceding vehicle is
detected
the ESP® is in operation or switched off
with the ESP® switch (page 71)
you set the automatic transmission
toP, R, or N while driving
the radar sensors are switched off
(
page 272)
the vehicle rolls backward
The segments in the multifunction display
go out, an acoustic signal sounds, and the
message “DISTRONIC PLUS Off” appears in
the multifunction display for approximately
5 seconds.If the vehicle has been stopped by
DISTRONIC Plus and a malfunction occurs
in the system, the message “Brake immedi-
ately” will appear on the multifunction dis-
play. Step on the brake immediately to
prevent the vehicle from rolling.
DISTRONIC Plus is then switched off and
the message disappears.
Warning!G
DISTRONIC Plus switches off and releases
the brakes when the vehicle decelerates be-
low the minimum speed of 20 mph
(30 km/h) by operation of the system un-
less DISTRONIC Plus detects a vehicle di-
rectly ahead of you. At that time the driver
must apply the brakes in order to reduce ve-
hicle speed further or bring it to a stop.
!Setting the automatic transmission toN
while driving cancels the DISTRONIC Plus. How-
ever, 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 DISTRONIC Plus. After brief accelera-
tion (e.g. for passing), DISTRONIC Plus will re-
sume to the last set speed.
426 Controls in detail
Driving systems
Driving with DISTRONIC Plus
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. Braking
will deactivate the DISTRONIC Plus sys-
tem.
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 Plus will switch off, and the
message:“DISTRONIC PLUS
currently unavailable
See Oper. Manual”
appears in the multifunction display.
For cleaning and care of the
DISTRONIC Plus sensor, see “Cleaning the
DISTRONIC Plus*/ PRE-SAFE
® Brake* sys-
tem sensors (USA only)”(
page 558).
Another cause might be that the radar sen-
sors have been manually switched off in
the instrument cluster control system.
Please verify that the radar sensors are
switched on (
page 272).
Warning!G
DISTRONIC Plus works to maintain the
speed selected by the driver unless a mov-
ing obstacle proceeding directly ahead of it
in the same travel direction is detected (e.g.
following another vehicle ahead of you at
your set distance).
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 Plus
could lose sight of a vehicle traveling in
front of it, then your vehicle could accel-
erate to the previously selected speed.
DISTRONIC Plus regulates only the distance
between your vehicle and those directly
ahead of it. It may not register stationary ob-
jects in the road, e.g.:
a stopped vehicle in a traffic jam
a disabled vehicle
an oncoming vehicle
The driver must always be alert, observe all
traffic and intercede as required by means
of steering or braking the vehicle.
Warning!G
DISTRONIC Plus should not be used in
snowy or icy road conditions.
iIf the message:
“DISTRONIC PLUS
currently unavailable
See Oper. Manual”
disappears during driving and the last speed
stored flashes for approximately 5 seconds, the
dirt (e.g. slush) has dissolved; DISTRONIC Plus is
available again.