page 98 MERCEDES-BENZ R-Class 2012 W251 Owners Manual

time, or adjusts the vehicle's speed to the
last speed stored.
Setting the specified minimum distance
You can set the specified minimum distance
for DISTRONIC by varying the time span
between one and two seconds. This time span
determines the distance that DISTRONIC
should maintain from the vehicle in front,
depending on the road speed. You can see
this distance in the multifunction display
( Y page 178).
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 thumbwheel ; towards
= .
DISTRONIC then maintains a greater
distance between your vehicle and the
vehicle in front.XTo decrease: turn thumbwheel ;
towards :.
DISTRONIC then maintains a shorter
distance between your vehicle and the
vehicle in front.
i Make sure that you maintain the
minimum distance to the vehicle in front as
required by law. Adjust the distance to the
vehicle in front if necessary.
DISTRONIC displays in the
speedometer
When DISTRONIC is activated, one or
two segments in the set speed range light up.
i For design reasons, the speed displayed
in the speedometer may differ slightly from
the speed set for DISTRONIC.
If DISTRONIC detects a vehicle in front,
segments ; between the speed of the
vehicle in front : and stored speed = light
up.
GWARNING
An intermittent warning sounds and the
distance warning lamp · in the instrument
cluster is illuminated if the Distronic system
calculates that the distance to the vehicle
ahead and your vehicle's current speed
indicate that the Distronic 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
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.
Driving systems177Driving and parkingZ

GWARNING
DISTRONIC brakes your vehicle with a
maximum deceleration of 13 ft/s 2
(4 m/s 2
).
This corresponds to approximately 40% of
your vehicle's maximum possible braking
power.
You must apply the brakes yourself to avoid a
collision. DISTRONIC brakes the vehicle to
restore the set distance to the vehicle in front
or to restore the set speed. In this case, the
brake pedal is depressed automatically,
which can be seen by a movement of the
brake pedal.
Always keep the driver's footwell clear,
including the area under the brake pedal.
Objects in this area may impair pedal
movement and cause the DISTRONIC braking
function to malfunction.
Do not place your foot under the brake pedal
– your foot could become caught.
DISTRONIC displays in the
multifunction display
XPress the V or U button to select the
DISTRONIC menu (Y page 201).
Display when DISTRONIC is deactivated
When DISTRONIC is deactivated, you will see
the following in the multifunction display:
:Vehicle in front, if detected;Distance indicator, displaying current
distance to the vehicle in front=Specified minimum distance to the
vehicle in front, adjustable?Own vehicleDisplay when DISTRONIC is activated
After this time, you will see the following in
the multifunction display while DISTRONIC is
activated::DISTRONIC activated;Stored speed
When activating DISTRONIC and when setting
the speed, stored speed ; appears for
around five seconds.
After approximately five seconds, current
saved speed ; is displayed in the
multifunction display's status indicator
DTR XXX Miles .
Deactivating DISTRONIC
There are several ways to deactivate
DISTRONIC:
XBriefly press the cruise control lever
forwards :.
or
XBrake.
i
The last speed stored remains stored until
you switch off the engine.
i DISTRONIC is not deactivated if you
depress the accelerator pedal. If you
accelerate to overtake, DISTRONIC adjusts
178Driving systemsDriving and parking

Other vehicles changing lane
DISTRONIC has not detected the vehicle
cutting in yet. The distance to this vehicle will
be too short.
Narrow vehicles
DISTRONIC has not yet detected the vehicle
in front on the edge of the road, because of
its narrow width. The distance to the vehicle
in front will be too short.
Obstructions and stationary vehicles
DISTRONIC does not brake for obstructions
or stationary vehicles. If, for example, the
detected vehicle turns a corner and reveals
an obstacle or stationary vehicle, DISTRONIC
will not brake for these.
Crossing vehicles
DISTRONIC may detect vehicles that are
crossing your lane by mistake. Activating
DISTRONIC at, for example, a traffic light with
crossing traffic, could cause your vehicle to
pull away at the wrong time.
Rear axle level control
The rear axle level control regulates the
vehicle level at the rear axle. The benefit of
this is that the vehicle level at the rear axle is
kept constant regardless of the load.
Observe the notes on driving with a trailer
( Y page 191).
AIRMATIC package
General notes
AIRMATIC enables a suspension tuning
setting to be selected and regulates the
damping behavior and level of your vehicle.
The system comprises two components: ADS
(Adaptive Damping System) ( Y page 181)
and level control ( Y page 181) .
Observe the notes on driving with a trailer
( Y page 191).
180Driving systemsDriving and parking

ADS (Adaptive Damping System)
ADS is continuously electronically-controlled.
It adapts the damping characteristics to suit
the current operating conditions. The
damping is controlled for each wheel
individually. This improves driving safety and
tire comfort.
This depends on:
R your driving style
R the road surface conditions
R the ADS setting
R the vehicle level setting
Your selection remains stored even if you
remove the SmartKey from the ignition lock.
You can choose between the following ADS
settings:
R AUTO for normal driving situations;
indicator lamps ; and = are off.
R SPORT for sporty driving; indicator
lamp ; is on.
R COMF for a more comfortable ride;
indicator lamp = is on.
XStart the engine.XPress button : repeatedly until the
desired setting is selected.
Level control
Level control adapts the vehicle level
automatically to the current operating and
driving situation. This results in reduced fuel
consumption and improved handling.
Make changes to the vehicle level while the
vehicle is in motion. This enables the vehicle
to adjust to the new level as quickly as
possible.
The vehicle level may change visibly when you
park the vehicle and the outside temperature
changes. When the temperature drops, the
vehicle level is lower; with an increase in
temperature, the vehicle level rises.
When you unlock the vehicle or open a door,
the vehicle begins to balance the load
discrepancies while still parked. However, for
significant level changes, e.g. after the
vehicle has been stationary for a long period,
the engine must be on. For safety reasons,
the vehicle is only lowered when the doors are
closed. Lowering is interrupted if a door is
opened and continues once the door has
been closed.GWARNING
Make sure no one is near the wheel housing
or under the vehicle when you lower the
vehicle while it is standing still. Limbs could
become wedged into or under the vehicle.
For safety reasons, the vehicle can only be
lowered with all doors and the tailgate closed.
Lowering is interrupted if a door or the tailgate
is opened and will continue after the door is
closed again.
! When driving in very poor road conditions,
select a high vehicle level in good time.
Make sure that there is always sufficient
ground clearance to prevent damage to the
vehicle.
! Remove the key from the ignition lock
before raising the vehicle completely, e.g.
with a vehicle lift.
Basic settings
Select raised level for very poor road
conditions ( Y page 182) or highway level for
normal road conditions ( Y page 182).
Driving systems181Driving and parkingZ

The vehicle is automatically lowered to high-
speed level when you:
R drive faster than 70 mph (112 km/h)
R drive between 60 mph (96 km/h) and
70 mph (112 km/h) for approximately
20 seconds.
The individual vehicle levels differ from
highway level as follows:
R +1.97 in (+ 50 mm) at the raised level
R +/-0 in (+/-0 mm) at the highway level
R -0.47 in (-12 mm) at the high-speed level
i The high-speed level is not available if you
are pulling a trailer. Observe the notes on
driving with a trailer ( Y page 191).
i Observe the speed limitations. Drive
carefully at an appropriate speed.
Raised level
Only select raised level when this is
appropriate for the road conditions.
Otherwise, fuel consumption may increase
and handling may be affected.
If you select the raised level at a speed of over
40 mph (64 km/h) the Level Selection
Not Permitted message appears in the
multifunction display.XStart the engine.
Indicator lamp ; is not lit:
XPress button :.
Indicator lamp ; flashes. The vehicle rises
to raised level.While the adjustment is taking place, a
message appears in the multifunction
display, e.g.:
If you press the V, U , * or &
button on the multifunction steering wheel,
the message will disappear.
Once the vehicle has reached raised level,
indicator lamp ; remains lit. A message
appears in the multifunction display for
approximately five seconds, e.g.:
The level is automatically taken up to highway
level if you drive faster than 25 mph
(40 km/h).
Highway level
! Make sure that there is enough ground
clearance when the vehicle is being
lowered. It could otherwise hit the ground,
damaging the underbody.
XMake sure that the doors are closed.XStart the engine.182Driving systemsDriving and parking

PARKTRONIC
Important safety notesGWARNING
The 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 remains with the driver.
GWARNING
Make sure no persons or animals are in or
near the area in which you are parking/
maneuvering. Otherwise, they could be
injured.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically when
you:
R switch on the ignition
R shift the transmission to position D, R or N
R release the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper.
:Sensors in the front bumper, left-hand
side (example)Range of the sensors
General notes
The sensors must be free of dirt, ice and
slush; otherwise they may not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
( Y page 291).
Side view
Top view
Front sensors
CenterApproximately 40 in
(approximately 100 cm)CornersApproximately 24 in
(approximately 60 cm)
Rear sensors
CenterApproximately 48 in
(approximately 120 cm)CornersApproximately 32 in
(approximately 80 cm)184Driving systemsDriving and parking

Problems with PARKTRONICProblemPossible causes/consequences and M SolutionsOnly the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is
deactivated after
approximately
20 seconds, and the
indicator lamp in the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.XIf problems persist, have PARKTRONIC checked at a qualified
specialist workshop.Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is
deactivated after
approximately 20
seconds.The PARKTRONIC sensors are dirty or there is interference.XClean the PARKTRONIC sensors ( Y page 291).XSwitch the ignition back on.The problem may be caused by an external source of radio or
ultrasound waves.XSee if PARKTRONIC functions in a different location.Rear view camera
Important safety notes
The rear view camera is an optical parking aid.
It shows the area behind your vehicle in the
COMAND display.
GWARNING
Make sure that no persons or animals are in
the maneuvering range. Otherwise, they
could be injured.
The rear view camera is located in the handle
strip of the tailgate.
:Rear view camera
View through the camera
The area behind the vehicle is displayed as a
mirror image, as in the rear-view mirror.
Driving systems187Driving and parkingZ

Information in the COMAND display (example)
Guide lines ; and = show the approximate
distance to the rear area. Yellow guide
line ; indicates a distance of approximately
3 ft (1 m) and red guide line = indicates a
distance of approximately 10 in (0.25 m). The
distances only apply to objects that are at
ground level. Blue guide lines : depict the
width required for the vehicle. They are used
to align the vehicle with the edge of the road,
e.g. the curb.
Blind Spot Assist
Important safety notes
Blind Spot Assist uses a radar sensor system
to monitor the areas on both sides of your
vehicle. It begins to work at speeds of
approximately 20 mph (30 km/h). A warning
display in the exterior mirrors draws your
attention to detected vehicles in the
monitored area. If you then indicate a turn
towards that side before changing lanes, you
will also receive visual and audible collision
warnings. The Blind Spot Assist monitoring
system uses sensors in the rear bumper.
GWARNING
Blind Spot Assist is only an aid designed to
assist driving. It may fail to detect some
vehicles and is no substitute for attentive
driving.
Blind Spot Assist cannot detect road and
traffic conditions. It may fail to detect narrow
vehicles, such as motorcycles or bicycles, or
may only detect them too late.
Monitoring may be affected by dirty sensors,
strong spray or poor visibility caused by snow,
rain or mist, for example. In this case, vehicles
are detected late or not at all.
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.
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.
For Blind Spot Assist to assist you when
driving, the radar sensor system must be
activated ( Y page 208) and operational.
Monitoring range of the sensors
Blind Spot Assist monitors the area shown in
the figure up to 10 ft (3 m) behind and
immediately adjacent to your vehicle.
Driving systems189Driving and parkingZ

side. When you are passing another vehicle,
the warning is emitted only if the difference
in speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if the
reverse gear is engaged. In this event, Blind
Spot Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.GWARNING
Blind Spot Assist is not active at speeds under
approximately 20 mph (30 km/h). The
indicator lamps in the exterior mirrors are
yellow. Vehicles in the monitoring range are
then not indicated.
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.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the turn
signal, a double warning tone sounds. Red
warning lamp : flashes. If the turn signal
remains on, detected vehicles are indicated
by the flashing of red warning lamp :. There
are no further warning tones.
Switching on Blind Spot Assist
XMake sure that the radar sensor system
( Y page 208) and Blind Spot Assist
( Y page 210) are activated in the on-board
computer.XTurn the SmartKey to position 2 in the
ignition lock.
Warning lamps : light up red in the
exterior mirrors for approximately 1.5
seconds and then turn yellow.
Trailer towing
When you attach a trailer, make sure you have
correctly established the electrical
connection. This can be accomplished by
checking the trailer lighting. In this event,
Blind Spot Assist is deactivated. The indicator
lamp in the exterior mirrors lights up yellow
and the Blind Spot Assist Currently
Unavailable See Operator's Manual
message appears in the multifunction
display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist when:
R the SmartKey is in position 2 in the
ignition lock.
R the engine is not running.
R the electrical connection to the trailer
has been established.
Trailer towing
Notes on towing a trailer
Important safety notes
GWARNING
When towing a trailer, incorrect equipment
and driving style could cause you to lose
control of the vehicle.
Towing incorrectly or not observing this
Operator's Manual could lead to damage to
the vehicle and/or serious injuries. Observe
the following guidelines to ensure safe trailer
towing.
Contact a Mercedes-Benz Center if you need
further explanation of the information
contained in this Operator's Manual.
General information
R Only install an approved trailer coupling on
your vehicle.
Further information on availability and on
installation is available from any authorized
Mercedes-Benz Center.
R The bumpers of your vehicle are not
suitable for installing detachable trailer
couplings.
Trailer towing191Driving and parkingZ

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops ( Y page 24).
Important safety notes
You will find an illustration of the instrument
cluster in the "At a glance" section
( Y page 29).
GWARNING
A driver's attention to the road and traffic
conditions must always be his/her primary
focus when driving.
For your safety and the safety of others,
selecting features through the multifunction
steering wheel should only be done by the
driver when traffic and road conditions permit
it to be done safely.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second.
GWARNING
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps
Rmalfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible.GWARNING
Malfunction and warning messages are only
indicated for certain systems and are
intentionally not very detailed. The
malfunction and warning messages are
simply a reminder with respect to the
operation of certain systems. They do not
replace the owner's and/or driver's
responsibility to maintain the vehicle's
operating safety. Have all required
maintenance and safety checks performed on
the vehicle. Bring the vehicle to an authorized
Mercedes-Benz Center to address the
malfunction and warning messages.
Displays and operation
Tachometer
The red band in the tachometer indicates the
engine's overrevving range.
! Do not drive in the overrevving range, as
this could damage the engine.
The fuel supply is interrupted to protect the
engine when the red band is reached.
Outside temperature display
The outside temperature display is in the
multifunction display ( Y page 200).
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
198Displays and operationOn-board computer and displays