reset MERCEDES-BENZ R-Class 2012 W251 Owner's Guide

RThe use of the cruise control can be
dangerous on winding roads or in heavy
traffic because conditions do not allow safe
driving at a constant speed.
R The use of the cruise control can be
dangerous on slippery roads. Rapid
changes in tire traction can result in wheel
spin and loss of control.
R Deactivate the cruise control when driving
in fog.
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
When cruise control 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.
Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate cruise control?To store the current speed or to call up
the last stored speed
When you activate cruise control, the stored
speed is shown in the status indicator of the
multifunction display:
R Canada only: e.g. ¯90 Km/h
Storing and maintaining the current
speed
You can store the current speed if you are
driving faster than 20 mph (30 km/h).
XAccelerate the vehicle to the desired
speed.XBriefly press the cruise control lever
up : or down ; to the pressure point.XRemove your foot from the accelerator
pedal.
Cruise control is activated. The vehicle
automatically maintains the stored speed.
i Cruise control may be unable to maintain
the stored speed on uphill gradients. The
stored speed is resumed when the gradient
evens out. Cruise control maintains the
stored speed on downhill gradients by
automatically applying the brakes.
Driving systems171Driving and parkingZ

Storing the current speed or calling up
the last stored speedGWARNING
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.
The first time cruise control is activated, it
stores the current speed or regulates the
speed of the vehicle to the previously
stored speed.
Setting a speed
GWARNING
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 to the
pressure point, 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) incrementsXBriefly 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 depress the 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.
172Driving systemsDriving and parking

DISTRONIC
Important safety notes
DISTRONIC 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 or towing a
trailer, 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 causes your vehicle to brake and
maintain the preset distance to the vehicle in
front.
GWARNING
The Distronic 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 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 cannot take street and traffic
conditions into account. Complex driving
situations are not always fully recognized by
the Distronic. This could result in wrong or
missing distance warnings.
If there is no vehicle driving in front of you,
DISTRONIC functions like cruise control at a
speed range between 20 mph (30 km/h) and
120 mph (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
(200 km/h).
Do not use DISTRONIC while driving on roads
with steep gradients.GWARNING
DISTRONIC distance control is not a
substitute for the driver's active involvement.
It does not react to pedestrians or stationary
objects and cannot detect or predict the
road's course and the movements of the
vehicles in front.
DISTRONIC can only brake using 40% of the
vehicle's maximum possible braking force.
The driver must always pay attention to road,
weather and traffic conditions. He must steer,
brake and drive the vehicle so that he
maintains control over it.
High-frequency sources such as toll stations,
velocity measurement systems, etc. may
cause DISTRONIC to malfunction.
GWARNING
The Distronic cannot take road and traffic
conditions into account. Only use the
Distronic if the road, weather and traffic
Driving systems173Driving and parkingZ

conditions make it advisable to travel at a
constant speed.GWARNING
Use of the Distronic can be dangerous on
slippery roads. Rapid changes in tire traction
can result in wheel spin and loss of control.
The Distronic does not function in adverse
sight and distance conditions. Do not use the
Distronic during conditions of fog, heavy rain,
snow or sleet.
GWARNING
The Distronic cannot take weather conditions
into account. Switch off the Distronic 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 system sensor cover is 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 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
Close attention to road and traffic conditions
is imperative at all times, regardless of
whether or not the Distronic is activated.
Use of the Distronic can be dangerous on
winding roads or in heavy traffic because
conditions do not allow safe driving at a
constant speed.
The Distronic will not react to stationary
objects in the roadway (e.g. a stopped vehicle
in a traffic jam or a disabled vehicle). The
Distronic will also not respond to oncoming
vehicles.
Switch off the Distronic
R when changing from the left to the right
lane if vehicles are moving more slowly in
the left lane
R when entering a turn lane or highway off
ramp
R in complex driving situations, such as in
highway construction zones
In these situations, the Distronic will continue
to maintain the set speed unless deactivated.
The Distronic is designed and intended only
to maintain a set speed and keep a set
distance from moving objects in front of it.
i 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.174Driving systemsDriving and parking

Cruise control lever:To store the current speed or a higher
speed;To store the current speed or a lower
speed=To deactivate DISTRONIC?To store the current speed or to call up
the last stored speed
Switching on DISTRONIC, storing and
maintaining the current speed
GWARNING
The vehicle can be braked when DISTRONIC
is activated. For this reason, deactivate
DISTRONIC if the vehicle is to be set in motion
by other means (e.g. in a car wash or by
towing).
You can activate DISTRONIC in the following
circumstances:
R if the engine has been started and you have
been driving for up to two minutes
R while driving, except if you brake
R if the parking brake is not applied
R if ESP ®
is activated
R if the transmission is in position D
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 not shown in the
multifunction display and is no longer being
detected, because it has changed lanes, for
example, DISTRONIC is deactivated and you
hear a warning tone.XBriefly pull the cruise control lever towards
you ? or press it up : or down ; to the
pressure point.
DISTRONIC is activated.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 You can use the cruise control lever to set
the stored speed and the thumbwheel on
the cruise control lever to set the specified
minimum distance ( Y page 177).
i If you do not fully release the accelerator
pedal, the DISTRONIC Override message
appears 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.
Driving
If there is no vehicle in front, DISTRONIC
operates in the same way as cruise control.
If a slower-moving vehicle is detected in front,
DISTRONIC causes your vehicle to brake and
maintain the preset distance to the vehicle in
front.
If DISTRONIC detects a faster-moving vehicle
in front, it increases the driving speed, but
only up to the desired speed you have stored.
GWARNING
If you depress the brake pedal, DISTRONIC is
deactivated. DISTRONIC will then no longer
brake your vehicle. In such cases, control the
distance from vehicles traveling in front with
the brake alone. You could otherwise cause
an accident and thereby injure yourself and
others. The driver remains fully responsible
Driving systems175Driving and parkingZ

for the vehicle's distance from other vehicles,
the speed being driven and for braking in good
time.
StoppingGWARNING
DISTRONIC must never be operated,
activated or deactivated by a passenger or
from outside the vehicle.
If DISTRONIC detects that the vehicle in front
is stopping, it brakes your vehicle until it is
stationary.
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 thumbwheel on
the cruise-control lever.
DISTRONIC is deactivated automatically
when stopping:
R on flat stretches of road or on downhill
gradients when the vehicle is stationary
R while the vehicle is still moving on uphill
gradients, to prevent the vehicle from
unexpectedly rolling back when
DISTRONIC is deactivated
If DISTRONIC is deactivated, you will hear a
warning tone.
XTo prevent the vehicle from rolling away,
apply the foot brake or parking brake.
Setting a speed
GWARNING
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 to the
pressure point, 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 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
the last 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 is activated and accepts the
current speed if it is activated for the first176Driving systemsDriving and parking

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

FunctionETrip computer menu (Y page 210)FTelephone menu (Y page 211)Standard display menu
Standard displayXPress the V or U button on the
steering wheel to select the standard
display.
Standard display
:Trip odometer;Odometer
You can select the following functions in the
Standard display menu using the & or
* button:
R tire pressure loss warning system
( Y page 329) (Canada only)
R tire pressure monitor ( Y page 331) (USA
only)
R coolant temperature ( Y page 202)
R digital speedometer or outside
temperature ( Y page 202)
R ASSYST PLUS service interval display
( Y page 287)
XTo reset the trip odometer: press and
hold the . reset button in the instrument
cluster until the trip odometer is reset.
Displaying the coolant temperature
GWARNING
Driving when your engine is overheated can
cause some fluids which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until
the engine has cooled down.XPress the V or U button on the
steering wheel to select the standard
display.XPress the & or * button to select the
coolant temperature.
Under normal driving conditions, with the
correct anti-corrosion and antifreeze additive
concentration, the reading may rise to
248 ‡(120 †).
! If the coolant temperature exceeds
248 ‡(120 †) do not continue driving. The
engine will otherwise be damaged.
Displaying the digital speedometer or
outside temperature
If you have selected the digital speedometer
for the status bar ( Y page 206), the outside
temperature is displayed here.
202Menus and submenusOn-board computer and displays

Settings menu
Introduction
The Settings menu can be used for:
R restoring the factory settings
R changing the instrument cluster settings
R changing the time/date settings 26
R changing the light settings
R changing the vehicle settings
R changing the convenience settings
Resetting to factory settings
For safety reasons, the Daytime Running
Lamps function in the Lighting submenu is
only reset when the engine is switched off.
XPress V or U on the steering wheel
to select the Settings menu.XPress and hold the . reset button on the
instrument cluster for approximately three
seconds.
A prompt appears in the multifunction
display asking you to confirm by pressing
the . reset button again.XPress the . reset button again.
The settings of most functions are restored
to the factory settings.
or
XIf you want to retain the settings, do not
press the . reset button a second time.
After approximately five seconds, the
Settings menu reappears.XPress the V or U button to select a
different menu.Instrument cluster
Selecting the unit of measurement for
distance
This function is only available in Canada.
The Display unit Speedometer/
Odometer function allows you to choose
whether certain displays appear in kilometers
or miles.
The selected unit of measurement for
distance applies to:
R the analog speedometer
R the odometer and the trip odometer
R the trip computer
R the navigation instruction in the
Navigation menu
R DISTRONIC
XPress the V or U button on the
steering wheel to select the Settings
menu.XPress the & button to call up the
selection of submenus.XPress the W or X button to select the
Instrument Cluster submenu.XPress the & button to select Display
Unit Speedometer/Odometer .XPress the W or X button to select
km or Miles as the unit of measurement for
distance.XPress the &, V or U button to
select a different display.
Selecting the unit of distance for the
digital speedometer
XPress V or U on the steering wheel
to select the Settings menu.XPress the & button to select submenus.XPress the W or X button to select the
Instrument cluster submenu.XPress the & button to display Display
unit Digital speedometer .26
This function is not available in vehicles with the navigation module.Menus and submenus205On-board computer and displaysZ

If you have switched the function on and you
fold the exterior mirrors in using the button
on the door ( Y page 110), they will not fold
out automatically. The exterior mirrors can
then only be folded out using the button on
the door.XPress V or U on the steering wheel
to select the Settings menu.XPress the & button to select submenus.XPress the W or X button to select the
Convenience submenu.XPress & to select Fold In Mirrors
When Locking .XPress W or X to activate/deactivate
the Fold Mirrors In When Locking
function.XPress the &, V or U button to
select a different display.
Additional functions menu
Activating/deactivating the distance
warning function
This function is only available with
DISTRONIC.
XPress V or U on the steering wheel
to select the Additional functions menu.XPress the & or * button to select the
Distance warning function.XPress the W or X button to activate
or deactivate the Distance warning
system.
When the distance warning function
( Y page 68) is activated, the Ä symbol
is shown in the lower multifunction display.XPress the &, V or U button to
select a different display.
Activating/deactivating Blind Spot
Assist
Further information about Blind Spot Assist
( Y page 189).
XPress V or U on the steering wheel
to select the Additional functions menu.XPress the & or * button to select the
Blind Spot Assist function.XPress the W or X button to switch
Blind Spot Assist on or off.XPress the &, V or U button to
select a different display.
Trip computer menu
Trip computer "From start" or "From
reset"
The values in the From Start submenu refer
to the start of your journey, while those in the
From Reset submenu refer to the last time
you reset ( Y page 211) this submenu.
XPress the V or U button on the
steering wheel to select the trip
computer menu.XPress the & or * button to select
From Start or From Reset .
Trip computer "From start" (example)
:Distance;Time=Average speed?Average fuel consumption
The From Start trip computer is reset
automatically when:
R the ignition has been switched off for more
than four hours.
R 999 hours have been exceeded.
R 9,999 miles have been exceeded.
210Menus and submenusOn-board computer and displays