Distronic MERCEDES-BENZ S-Class 2012 W221 User Guide

by the engine's air suction nozzles and this
can cause engine damage.
Winter driving
General notes
GWARNING
If the vehicle becomes trapped in snow,
ensure that snow is kept away from the
exhaust pipe and from around the vehicle as
long as the engine is running. Otherwise,
poisonous carbon monoxide (CO) may enter
the vehicle, resulting in loss of consciousness
and even death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
At the onset of winter, have your vehicle
winterproofed at a qualified specialist
workshop, e.g. at an authorized Mercedes-
Benz Center.
Observe the notes in the "Winter operation"
section ( Y page 492).
Driving with summer tires
Observe the notes in the "Winter operation"
section ( Y page 492).
Slippery road surfaces
GWARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges.
GWARNING
On slippery road surfaces, never downshift in
order to obtain braking action. This could
result in drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of loss of control.
Drive particularly carefully on slippery road
surfaces. Avoid sudden acceleration, steering
and braking maneuvers. Do not use cruise
control or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:XShift the transmission to position N.
i
For more information on driving with
snow chains, see ( Y page 493).
GWARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Driving systems
Cruise control
Important safety notes
Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhill gradients, especially if the
vehicle is laden, you must select shift range
1 , 2 or 3 in good time. By doing so, you will
make use of the braking effect of the engine,
which relieves the load on the brake system
and prevents the brakes from overheating
and wearing too quickly.
Use cruise control only if road and traffic
conditions make it appropriate to maintain a
steady speed for a prolonged period. You can
set any road speed above 20 mph
(30 km/h).
GWARNING
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always
remain responsible for the vehicle's speed
and for safe brake operation.
330Driving systemsDriving and parking

Setting a speedGWARNING
Keep in mind that it may take a brief moment
until the vehicle has made the necessary
adjustments.
Increase or decrease the set vehicle speed to
a value that the prevailing road conditions and
legal speed limits permit. Otherwise, sudden
and unexpected acceleration or deceleration
of the vehicle could cause an accident and/
or serious injury to you and others.
XPress the cruise control lever up : for a
higher speed or down ; for a lower speed.XKeep the cruise control lever pressed until
the desired speed is reached.XRelease the cruise control lever.
The new speed is stored.
i Cruise control is not deactivated if you
depress the accelerator pedal. For
example, if you accelerate briefly to
overtake, cruise control adjusts the
vehicle's speed to the last speed stored
after you have finished overtaking.
Making adjustments in 1 mph (Canada:
1 km/h) increments
XBriefly press the cruise control lever to the
pressure point, up : for a higher speed or
down ; for a lower speed.
The last speed stored is increased or
reduced.
Making adjustments in 5 mph (Canada:
10 km/h) increments
XBriefly press the cruise control lever
beyond the pressure point, up : for a
higher speed or down ; for a lower speed.
The last speed stored is increased or
reduced.Deactivating cruise control
There are several ways to deactivate cruise
control:
XBriefly press the cruise control lever
forwards =.
or
XBrake.
Cruise control is automatically deactivated if:
R you engage the electric parking brake.
R you are driving below 20 mph (30 km/h).
R ESP ®
intervenes or you deactivate ESP ®
.
R you shift the transmission to position N
while driving.
If cruise control is deactivated, you will hear
a warning tone. You will see the Cruise
Control Off message in the multifunction
display for approximately five seconds.
i The last speed stored is cleared when you
switch off the engine.
DISTRONIC PLUS
Important safety notes
DISTRONIC PLUS regulates the speed and
automatically helps you maintain the
distance to the vehicle detected in front. It
brakes automatically in order to avoid
exceeding the set speed.
On long and steep downhill gradients,
especially if the vehicle is laden, you must
select shift range 1, 2 or 3 in good time. By
doing so, you will make use of the braking
effect of the engine, which relieves the load
on the brake system and prevents the brakes
from overheating and wearing too quickly.
If a slower-moving vehicle is detected in front,
DISTRONIC PLUS causes your vehicle to
brake and maintain a preset distance to the
vehicle in front.
GWARNING
HYBRID vehicles: It is imperative that you read
the HYBRID Supplemental Operating
332Driving systemsDriving and parking

Instructions included in your vehicle literature
portfolio. You may otherwise not receive all
necessary safety information and warning for
the operation of your vehicle.GWARNING
The DISTRONIC PLUS requires familiarity with
its operational characteristics. We strongly
recommend that you review the following
information carefully before operating the
system.
GWARNING
When DISTRONIC brakes, the brake pedal is
pulled back (i.e. operated automatically). The
area around the pedal must not be blocked by
obstacles:
R do not place any objects in the footwell.
R ensure that floormats and carpets are fixed
securely. In particular, do not place several
floormats on top of one another.
R do not place your foot under the brake
pedal, as it could become trapped.
Non-compliance could lead you to cause an
accident in which you and/or others could be
seriously injured.
GWARNING
The DISTRONIC PLUS is a convenience
system. Its speed adjustment reduction
capability is intended to make cruise control
more effective and usable when traffic speeds
vary. It is not however, intended to, nor does
it, replace the need for extreme care.
The responsibility for the vehicle's speed,
distance to the preceding vehicle and, most
importantly, brake operation to ensure a safe
stopping distance, always remains with the
driver.
The DISTRONIC PLUS cannot take street and
traffic conditions into account.
Complex driving situations are not always
fully recognized by the DISTRONIC PLUS. This
could result in wrong or missing distance
warnings.
If you want DISTRONIC PLUS to assist you,
the radar sensor system must be activated
( Y page 387) and operational.
If there is no vehicle driving in front of you,
DISTRONIC PLUS functions like cruise
control at a speed range between 20 mph
(Canada: 30 km/h) and 120 mph
(Canada: 200 km/h). If a vehicle is driving in
front of you, it functions at a speed range
between 0 mph (0 km/h) and 120 mph
(Canada: 200 km/h).
Do not use DISTRONIC PLUS while driving on
roads with steep gradients.
As DISTRONIC PLUS transmits radar waves,
it can resemble the radar detectors of the
responsible authorities. You can refer to the
applicable section in the Operator's Manual if
there are any questions concerning this.
i USA 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 device 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.GWARNING
The DISTRONIC PLUS adaptive cruise control
is not a substitute for active driving
involvement. It does not react to pedestrians
or on stationary objects, nor does it recognize
or predict the curvature and lane layout or the
movement of preceding vehicles. The
DISTRONIC PLUS can only apply a maximum
of 40% of the vehicle's braking power.
The DISTRONIC PLUS may not detect narrow
vehicles 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 the road, weather and traffic
Driving systems333Driving and parkingZ

conditions. Additionally, the driver must
provide the steering, braking and other driving
inputs necessary to remain in control of the
vehicle.
High-frequency sources such as toll stations,
speed measuring systems etc. can cause the
DISTRONIC PLUS system to temporarily
cease functioning.GWARNING
The DISTRONIC PLUS cannot take road and
traffic conditions into account. Only use the
DISTRONIC PLUS if the road, weather and
traffic conditions make it advisable to travel
at a constant speed.
GWARNING
Use of the DISTRONIC PLUS can be
dangerous on slippery roads. Rapid changes
in tire traction can result in wheel spin and
loss of control.
The DISTRONIC PLUS does not function in
adverse sight and distance conditions. Do not
use the DISTRONIC PLUS during conditions of
fog, heavy rain, snow or sleet.
GWARNING
The DISTRONIC PLUS cannot take weather
conditions into account. Switch off the
DISTRONIC PLUS or do not switch it on if:
R roads are slippery or covered with snow or
ice. The wheels could lose traction while
braking or accelerating, and the vehicle
could skid.
R the DISTRONIC PLUS system sensor covers
are dirty or visibility is diminished due to
snow, rain or fog, for example. The distance
control system functionality could be
impaired.
Always pay attention to surrounding traffic
conditions even while the DISTRONIC PLUS is
switched on. Otherwise, you may not be able
to recognize dangerous situations until it is
too late. This could cause an accident in which
you and/or others could be injured.
GWARNING
The "Resume" function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
GWARNING
Your undivided attention to street and traffic
conditions is necessary at all times whether
DISTRONIC PLUS is active or not.
The use of DISTRONIC PLUS can be
dangerous on winding roads or in heavy traffic
because conditions do not allow safe driving
at a constant speed.
DISTRONIC PLUS does not react to stationary
objects on the road (for example, a vehicle
stopped in traffic or an abandoned vehicle).
DISTRONIC PLUS likewise does not react to
oncoming vehicles.
Deactivate DISTRONIC PLUS:
R when changing to the right lane, if the
vehicles in the left lane are driving slower
R when driving into a filter lane or an
expressway exit
R in complex driving situations, for example
in construction sites on an expressway
In these situations DISTRONIC PLUS will
maintain the set speed if it is not deactivated.
DISTRONIC PLUS is intended only for
maintaining a set speed and a set distance
from the objects moving in front of the
vehicle.
GWARNING
An intermittent warning sounds and the
distance warning lamp · 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 the DISTRONIC PLUS will
not be capable of slowing the vehicle
sufficiently to maintain the preset following
distance, which creates a danger of a
collision.
334Driving systemsDriving and parking

Immediately brake the vehicle to increase
your distance to the preceding vehicle. The
warning sound is intended as a final caution
in which you should intercede with your own
braking inputs to avoid a potentially
dangerous 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
avoided.
Tailgating increases the risk of an accident.GWARNING
DISTRONIC PLUS brakes your vehicle with a
maximum deceleration of 13 ft/s 2
(4 m/s 2
).
This is equivalent to approximately 40 % of
your vehicle's maximum possible
deceleration.
You need to brake yourself to prevent a
collision. DISTRONIC PLUS brakes the vehicle
to restore the set distance from the vehicle
ahead or the set speed.
GWARNING
If you do not receive visual or acoustic
warning 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 drivers
responsibility to apply the brakes in order to
control the vehicle and avoid a collision.
Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate DISTRONIC PLUS?To store the current speed or to call up
the last stored speedATo set the specified minimum distance
Switching on DISTRONIC PLUS, storing
the current speed and maintaining it
Important safety notes
GWARNING
The vehicle can be braked when DISTRONIC
PLUS is activated. For this reason, deactivate
DISTRONIC PLUS if the vehicle is to be set in
motion by other means (e.g. in a car wash or
by towing).
In order to activate DISTRONIC PLUS, the
following conditions must be fulfilled:
R the engine must be started. It may take up
to two minutes after pulling away before
DISTRONIC PLUS is operational.
R the electric parking brake must be
released.
R ESP ®
must be activated but not
intervening.
R the transmission must be in position D.
R the hood must be closed.
Driving systems335Driving and parkingZ

Rthe driver's door must be closed when you
shift from P to D or your seat belt must be
fastened.
R the front-passenger door and rear doors
must be closed.
R the vehicle must not skid.
Activating while driving
When driving at speeds below 20 mph
(30 km/h) , you can only activate DISTRONIC
PLUS if the vehicle in front has been detected
and is shown in the multifunction display. If
the vehicle in front is no longer detected and
shown, DISTRONIC PLUS is deactivated and
a warning tone sounds.XBriefly pull the cruise control lever towards
you ?, or briefly press up : or down ;.
DISTRONIC PLUS is selected.XKeep the cruise control lever pressed
up : or down ; until the desired speed
is set.XRemove your foot from the accelerator
pedal.
Your vehicle adapts its speed to that of the
vehicle in front, but only up to the desired
stored speed.
i If you do not fully release the accelerator
pedal, the DISTRONIC PLUS Override
message is shown in the multifunction
display. The set distance to a slower-
moving vehicle in front will then not be
maintained. You will be driving at the speed
you determine by the position of the
accelerator pedal.
Activating when driving towards a
stationary vehicle
If the vehicle in front of you is stationary, you
can only activate DISTRONIC PLUS once your
vehicle is stationary as well.
XBriefly pull the cruise control lever towards
you ?, or briefly press up : or down ;.
DISTRONIC PLUS is selected.
i DISTRONIC PLUS can only be activated at
under 20 mph (30 km/h) if a vehicle in front
has been detected. Therefore, the
DISTRONIC PLUS distance display in the
instrument cluster should be activated
( Y page 383).XKeep the cruise control lever pressed
up : or down ; until the desired speed
is set.
i You can use the cruise control lever to set
the stored speed and the control on the
cruise control lever to set the specified
minimum distance ( Y page 338).
Pulling away
XIf the vehicle in front pulls away: remove
your foot from the brake pedal.XBriefly pull the cruise control lever towards
you ?.
or
XAccelerate briefly.
Your vehicle pulls away and adapts its
speed to that of the vehicle in front.
Driving
If there is no vehicle in front, DISTRONIC
PLUS operates in the same way as cruise
control.
If a slower-moving vehicle is detected in front,
DISTRONIC causes your vehicle to brake. This
maintains the preset distance to the vehicle
in front.
If DISTRONIC PLUS detects a faster-moving
vehicle in front, it increases the driving speed
of your vehicle, but only up to the desired
speed you have stored.
GWARNING
If you depress the brake, DISTRONIC PLUS is
deactivated unless your vehicle is stationary.
DISTRONIC PLUS then no longer brakes your
vehicle. In such cases, control the distance
from vehicles travelling in front with the brake
alone. You could otherwise cause an accident
and thereby injure yourself and others. The
driver remains fully responsible for the
vehicle's distance from other vehicles, the
336Driving systemsDriving and parking

speed being driven and for braking in good
time.
Changing lanes
If you wish to change to the passing lane (in
left-hand-drive vehicles, the passing lane is
the left-hand lane), DISTRONIC PLUS
supports you if:
R you are driving faster than 40 mph
(60 km/h).
R DISTRONIC PLUS is maintaining the
distance to a vehicle in front.
R you switch on the appropriate turn signals.
R DISTRONIC PLUS does not detect a danger
of collision.
If these conditions are met, your vehicle is
accelerated. Acceleration will be interrupted
if changing lanes takes too long or if the
distance between your vehicle and the
vehicle in front becomes too small.GWARNING
DISTRONIC PLUS and Active Blind Spot Assist
are only aids designed to assist driving.
They do not relieve you of the responsibility
of paying attention. The driver remains fully
responsible for the vehicle's distance from
other vehicles, the vehicle's speed and for
braking in good time. Always pay attention to
traffic conditions and your surroundings.
Otherwise, you may fail to recognize dangers
in time, cause an accident and injure yourself
and others.
Stopping
GWARNING
Never get out of the vehicle when DISTRONIC
PLUS is activated.
DISTRONIC PLUS must also never be
operated, activated or deactivated by a
passenger or from outside the vehicle.
DISTRONIC PLUS does not replace the
electric parking brake and must not be used
for parking.
The DISTRONIC PLUS braking effect is
canceled and the vehicle can start moving if:
R DISTRONIC PLUS is deactivated using the
cruise control lever.
R you accelerate.
R there is a malfunction in the system or an
interruption in the power supply, e.g.
battery failure.
R the electrical system in the engine
compartment, the battery or the fuses are
tampered with.
R the battery is disconnected.
If you wish to leave the vehicle or park it,
deactivate DISTRONIC PLUS and secure the
vehicle against rolling away.
If DISTRONIC PLUS detects that the vehicle
in front is stopping, it brakes your vehicle until
it is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
i Depending on the specified minimum
distance, your vehicle will come to a
standstill at a sufficient distance behind the
vehicle in front. The specified minimum
distance is set using the control on the
cruise control lever.
Setting a speedGWARNING
Keep in mind that it may take a brief moment
until the vehicle has made the necessary
adjustments.
Increase or decrease the set vehicle speed to
a value that the prevailing road conditions and
legal speed limits permit. Otherwise, sudden
and unexpected acceleration or deceleration
of the vehicle could cause an accident and/
or serious injury to you and others.
Driving systems337Driving and parkingZ

XPress the cruise control lever up : for a
higher speed or down ; for a lower speed.XKeep the cruise control lever pressed until
the desired speed is reached.XRelease the cruise control lever.
The new speed is stored. DISTRONIC PLUS
is activated and adjusts the vehicle's speed
to the new speed stored.
Making adjustments in 1 mph (Canada:
1 km/h) increments
XBriefly press the cruise control lever to the
pressure point, up : for a higher speed or
down ; for a lower speed.
The last speed stored is increased or
reduced.
Making adjustments in 5 mph (Canada:
10 km/h) increments
XBriefly press the cruise control lever
beyond the pressure point, up : for a
higher speed or down ; for a lower speed.
The last speed stored is increased or
reduced.
Storing the current speed or calling up
a stored speed
GWARNING
The set speed stored in memory should only
be set again if prevailing road conditions and
legal speed limits permit. Possible
acceleration or deceleration differences
arising from returning to the preset speed
could cause an accident and/or serious injury
to you and others.
XBriefly pull the cruise control lever towards
you ?.XRemove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it sets the vehicle cruise
speed to the previously stored value.Sets the specified minimum distance
You can set the specified minimum distance
for DISTRONIC PLUS by varying the time span
between one and two seconds. With this
function, you can set the minimum distance
that DISTRONIC PLUS keeps to the vehicle in
front, dependent on vehicle speed. You can
see this distance in the multifunction display
( Y page 339).
GWARNING
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
recommendations for safe following distance.
XTo increase: turn control ; in direction
= .
DISTRONIC PLUS then maintains a greater
distance between your vehicle and the
vehicle in front.XTo decrease: turn control ; in
direction :.
DISTRONIC PLUS then maintains a shorter
distance between your vehicle and the
vehicle in front.
i Make sure that you maintain a sufficient
and safe distance from the vehicle in front.
Adjust the distance to the vehicle in front if
necessary.
338Driving systemsDriving and parking

DISTRONIC PLUS displays in the
speedometer
When you switch on DISTRONIC PLUS,
triangle ; shows the stored speed.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC PLUS.
If DISTRONIC PLUS detects a vehicle in front,
the speedometer dial lights up between
speed of the vehicle in front : and stored
speed ;.
DISTRONIC PLUS displays in the
multifunction display
General notes
You can select the distance display in the
Assistance menu ( Y page 383) of the on-
board computer.
Display when DISTRONIC PLUS is
deactivated
XSelect the Distance Display function
using the on-board computer
( Y page 383).
When DISTRONIC PLUS is deactivated, you
will see the following in the multifunction
display:
:Symbol for activated PRE-SAFE ®
Brake;Vehicle in front, if detected=Distance indicator, current distance to
the vehicle in front?Specified minimum distance to the
vehicle in front; adjustableAOwn vehicle
Display when DISTRONIC PLUS is
activated
XSelect the Distance Display function
using the on-board computer
( Y page 383).
You will see the stored speed for about five
seconds when you activate DISTRONIC PLUS.
After this time, you will see the following in
the multifunction display while DISTRONIC
PLUS is activated:
:DISTRONIC PLUS activated;Own vehicle=Specified minimum distance to the
vehicle in front; adjustable?Vehicle in front, if detectedDriving systems339Driving and parkingZ

Deactivating DISTRONIC PLUS
There are several ways to deactivate
DISTRONIC PLUS:
XBriefly press the cruise control lever
forwards :.
or
XBrake, unless the vehicle is stationary.
When you deactivate DISTRONIC PLUS, the
DISTRONIC PLUS Off message is shown in
the multifunction display for approximately
five seconds.
i The last speed stored remains stored until
you switch off the engine.
i DISTRONIC PLUS is not deactivated if you
depress the accelerator pedal. If you
accelerate to overtake, DISTRONIC PLUS
adjusts the vehicle's speed to the last
speed stored after you have finished
overtaking.
DISTRONIC PLUS is automatically
deactivated if:
R you engage the electric parking brake or if
the vehicle is automatically secured with
the electric parking brake.
R you are driving slower than
15 mph (25 km/h) and there is no vehicle
in front, or if the vehicle in front is no longer
detected.
R ESP ®
intervenes or you deactivate ESP ®
.
R the transmission is in the P, R or N position.
R you switch off the radar sensor system
( Y page 387).
R
you pull the cruise control lever towards
you in order to pull away and the front-
passenger door or one of the rear doors is
open.
R the vehicle has skidded.
If DISTRONIC PLUS is deactivated, you will
hear a warning tone. The DISTRONIC PLUS
Off message is shown in the multifunction
display for approximately five seconds.GWARNING
The DISTRONIC PLUS 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
unless the DISTRONIC PLUS detects a vehicle
directly ahead of you. At that time the driver
must apply the brakes in order to reduce
vehicle speed further or bring it to a stop.
Tips for driving with DISTRONIC PLUS
Important safety notes
The following contains descriptions of certain
road and traffic conditions in which you must
be particularly attentive. In such situations,
brake if necessary. DISTRONIC PLUS is then
deactivated.
GWARNING
The DISTRONIC PLUS works to maintain the
speed selected by the driver unless a moving
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:
R Your vehicle can pass another vehicle after
you have changed lanes.
R While in a sharp turn or if the preceding
vehicle is in a sharp turn, the DISTRONIC
PLUS could lose sight of the preceding
vehicle. Your vehicle could then accelerate
to the previously selected speed.
340Driving systemsDriving and parking