MERCEDES-BENZ R-Class 2012 W251 Owner's Manual

the vehicle's speed to the last speed stored
after you have finished overtaking.
DISTRONIC is automatically deactivated if:
R you apply the parking brake.
R you are driving slower than
20 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 you shift the transmission to P, R or N.
If DISTRONIC is deactivated, you will hear a
warning tone. You will see the DISTRONIC
Off message in the multifunction display for
approximately five seconds.
Tips for driving with DISTRONIC
The following contains descriptions of certain
road and traffic conditions in which you must
be particularly attentive. In such situations,
brake if necessary. DISTRONIC is then
deactivated.
GWARNING
The Distronic 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
could lose sight of the preceding vehicle.
Your vehicle could then accelerate to the
previously selected speed.
The Distronic regulates only the distance
between your vehicle and those directly
ahead of it, but does not register stationary
objects in the road, e.g.:
R a stopped vehicle in a traffic jam
R a disabled vehicle
R an oncoming vehicle
The driver must always be alert, observe all
traffic and intercede as required by means of
steering or braking the vehicle.GWARNING
The Distronic should not be used in snowy or
icy road conditions.
Cornering, going into and coming out of a
bend
The ability of DISTRONIC to detect vehicles
when cornering is limited. Your vehicle may
brake unexpectedly or late.
Vehicles traveling on a different line
DISTRONIC may not detect vehicles traveling
on a different line. The distance to the vehicle
in front will be too short.
Driving systems179Driving and parkingZ

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

If indicator lamp ; is lit:XPress button :.
Indicator lamp ; flashes. The vehicle is
lowered to highway 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 highway level has been reached,
indicator lamp ; goes out. A message
appears in the multifunction display for
approximately five seconds, e.g.:
The level is automatically raised from high-
speed level to highway level if the speed falls
below 40 mph (64 km/h). The level is
automatically taken up to highway level if you
drive faster than 25 mph (40 km/h).
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are
permanently driven. Together with ESP ®
and
4ETS , it improves the traction of your vehicle
whenever a drive wheel spins due to
insufficient grip.
GWARNING
If a drive wheel is spinning due to insufficient
traction:
R While driving off, apply as little throttle as
possible.
R While driving, ease up on the accelerator
pedal.
R Adapt your speed and driving style to the
prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents
resulting from excessive speed.
! Never tow the vehicle with one axle
raised. This may damage the transfer case.
Damage of this sort is not covered by the
Mercedes-Benz Limited Warranty. All
wheels must remain either on the ground
or be fully raised. Observe the instructions
for towing the vehicle with all wheels in full
contact with the ground.
i In wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if
you use winter tires ( M+S tires), with snow
chains if necessary.
! When testing the parking brake, operate
the vehicle only briefly (for a maximum of
ten seconds) on a brake test dynamometer.
When doing this, turn the key to position
0 or 1 in the ignition. Failure to do this can
cause damage to the drive train or the
brake system.
! Function or performance tests may only
be performed on a 2-axle dynamometer. If
you wish to operate the vehicle on such a
dynamometer, please consult an
authorized Mercedes-Benz Center
beforehand. You could otherwise damage
the drive train or the brake system.
Driving systems183Driving and parkingZ

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

! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves.
Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
Minimum distanceCenterApproximately 8 in
(approximately 20 cm)CornersApproximately 6 in
(approximately 15 cm)
If there is an obstacle within this range, the
relevant warning displays light up and a
warning tone sounds. If the distance falls
below the minimum, the distance may no
longer be shown.
Warning displays
The warning displays show the distance
between the sensors and the obstacle. The
warning display for the front area is located
on the dashboard above the center air vents.
The warning display for the rear area is in the
roof lamp in the rear compartment.
Warning display for the front area
:Segments on the left-hand side of the
vehicle;Segments on the right-hand side of the
vehicle=Segments showing operational readiness
The warning display for each side of the
vehicle is divided into five yellow and two red
segments. PARKTRONIC is operational if
yellow segments showing operational
readiness = light up.
The selected transmission position
determines which warning display is active
when the engine is running.
Transmission
positionWarning displayDFront area activatedR or NRear and front areas
activatedPNo areas activated
One or more segments light up as the vehicle
approaches an obstacle, depending on the
vehicle's distance from the obstacle.
From the:
R sixth segment onwards, you will hear an
intermittent warning tone for
approximately two seconds.
R seventh segment onwards, you will hear a
warning tone for approximately two
seconds. This indicates that you have now
reached the minimum distance.
Driving systems185Driving and parkingZ

Deactivating/activating PARKTRONIC:To deactivate/activate PARKTRONIC;Indicator lamp
If indicator lamp ; lights up, PARKTRONIC is
deactivated.
i PARKTRONIC is automatically activated
when you turn the SmartKey to position 2
in the ignition lock.
Trailer towing
PARKTRONIC is deactivated for the rear area
when you establish an electrical connection
between your vehicle and a trailer.
! Remove the detachable ball coupling if
the trailer tow hitch is not required.
PARKTRONIC measures the minimum
detection range to an obstacle from the
bumper, not the ball coupling.
186Driving 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

GWARNING
The rear view camera is only an aid and may
display obstacles
R from a distorted perspective
R inaccurately
R may not display obstacles at all
The rear view camera does not relieve you of
the responsibility to be cautious. Take care
and pay careful attention. The rear view
camera may not show objects which are
R very close to the rear bumper
R under the rear bumper
R above the tailgate handle
You are responsible for safety at all times and
must continue to pay attention to the
immediate surroundings when parking and
maneuvering. This includes the area behind,
in front of, and beside the vehicle. Otherwise
you could endanger yourself and/or others.
GWARNING
The rear view camera will not function or will
not fully function if:
R the tailgate is open
R it is raining or snowing strongly or if it is
foggy
R it is night or if you are parking/
maneuvering your vehicle in a very dark
area
R a very bright white light is affecting the
camera
R the immediate vicinity is illuminated with
fluorescent light (the display can flicker)
R temperature changes abruptly, for example
if you drive out of the cold into a heated
garage (condensation on the lens)
R the camera lens is dirty or covered
R the rear of your vehicle is damaged
In this case, have the position and the
setting of the camera checked at a
specialist workshop. Mercedes-Benz
recommends that you consult a Mercedes-
Benz Center for this purpose.
Do not use the rear view camera in these
situations. You could otherwise injure
yourself and other people and/or cause
damage - including damage to your vehicle -
while parking/maneuvering.
Activating the rear view cameraXMake sure that the SmartKey is in position
2 in the ignition lock.XMake sure that the "rear view camera"
function is selected in COMAND (see the
separate operating instructions for
COMAND).XEngage reverse gear.
The area behind the vehicle is shown in the
COMAND display with guide lines.
Guide lines in the COMAND display
GWARNING
Use of rear view camera can be dangerous if
you are color-blind or have impaired color
vision.
Only use rear view camera if you can see and
distinguish all colored guidelines shown by
rear view camera on the COMAND system
display.
GWARNING
Please note that objects that do not touch the
ground may appear to be further away than
they actually are, for example:
R the bumper of a vehicle parked behind you
R the trailer drawbar
R the ball coupling of a trailer tow hitch
R the rear end of a truck
R a slanted post
In such cases, you should not use the guide
lines to judge the distance. You may misjudge
the distance, which increases the risk of
impacting the objects.
Even if the object you approach is directly on
the ground, do not approach the object any
closer than the red guide line.
188Driving systemsDriving and parking