instrument cluster MERCEDES-BENZ R-Class 2012 W251 Owner's Guide

5¯ Continuous wipe, fastBí Single wipe/ î To wipe the
windshield using washer fluidXSwitch on the ignition.XTurn the combination switch to the
corresponding position.
! Intermittent wiping with rain sensor: due
to optical influences and the windshield
becoming dirty in dry weather conditions,
the windshield wipers may be activated
inadvertently. This could then damage the
windshield wiper blades or scratch the
windshield.
For this reason, you should always switch
off the windshield wipers in dry weather.
In the Ä or Å position, the appropriate
wiping frequency is set automatically
according to the intensity of the rain. In
the Å position, the rain sensor is more
sensitive than in the Ä position, causing
the windshield wipers to wipe more
frequently.
Switching the rear window wiper on/
off
Combination switch
:è Switch2ô To wipe with washer fluid3I To switch on intermittent wiping40 To switch off intermittent wiping5ô To wipe with washer fluidXTurn the SmartKey to position 1 or 2 in the
ignition lock.XTurn switch : on the combination switch
to the corresponding position.
When the rear window wiper is switched on,
the icon appears in the instrument cluster.
Replacing the wiper blades
Important safety notes
GWARNING
For safety reasons, switch off the windshield
wipers and remove the key from the ignition
lock before changing the wiper blades
(vehicles with KEYLESS-GO: make sure that
the on-board electronics are in state 0).
Otherwise, the wiper motor could be switched
on suddenly and cause injury.
! To avoid damaging the wiper blades,
make sure that you touch only the wiper
arm of the wiper.
! Never open the hood if a windshield wiper
arm has been folded away from the
windshield.
Never fold a windshield wiper arm without
a wiper blade back onto the windshield/
rear window.
Hold the windshield wiper arm firmly when
you change the wiper blade. If you release
the windshield wiper arm without a wiper
blade and it falls onto the windshield, the
windshield may be damaged by the force of
the impact.
Mercedes-Benz recommends that you have
the wiper blades replaced by a qualified
specialist workshop, e.g. at an authorized
Mercedes-Benz Center.
Windshield wipers125Lights and windshield wipersZ

Start/Stop button
=USA only?Canada onlyXPosition 0: if Start/Stop button : has not
yet been pressed, this corresponds to the
SmartKey being removed from the ignition.XPosition 1: press Start/Stop button :.
You can now activate the windshield
wipers, for example.
i If you then open the driver's door when in
this position, the power supply is
deactivated.
XPosition 2 (ignition): press Start/Stop
button : twice.
i
If you press Start/Stop button : once
when in this position and the driver's door
is open, the power supply is deactivated
again.
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. If an indicator lamp does not go out after
the engine is started or if it lights up while the
vehicle is in motion, see ( Y page 239).
Starting the engine
Important safety notes
GWARNING
Inhalation of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
! Do not depress the accelerator pedal
when starting the engine.
i Vehicles with a gasoline engine: the
catalytic converter is preheated for up to
30 seconds after a cold start. During this
time, the engine sound may be different.
Automatic transmissionXShift the transmission to position P.
The transmission position display in the
multifunction display shows P.
i
You can also start the engine when the
transmission is in position N.
Starting procedure with the SmartKey
i To start the engine using the SmartKey
instead of KEYLESS-GO, pull the Start/
Stop button out of the ignition lock.
XTo start a gasoline engine: turn the
SmartKey to position 3 in the ignition lock
( Y page 145) and release it as soon as the
engine is running.XTo start a diesel engine: turn the
SmartKey to position 2 in the ignition lock
( Y page 145).
The % preglow indicator lamp in the
instrument cluster lights up.XWhen the % preglow indicator lamp
goes out, turn the SmartKey to position 3
( Y page 145) and release it as soon as the
engine is running.
i You can start the engine without preglow
if the engine is warm.
146DrivingDriving and parking

Problems with the engineProblemPossible causes/consequences and M SolutionsThe engine does not
start. The starter motor
can be heard.R There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.XBefore attempting to start the engine again, turn the SmartKey
in the ignition back to position 0 or press the Start/Stop button
repeatedly until all indicator lamps in the instrument cluster go
out.XTry to start the engine again ( Y page 146). Avoid excessively
long and frequent attempts to start the engine as these will drain
the battery.
If the engine does not start after several attempts:
XConsult a qualified specialist workshop, e.g. an authorized
Mercedes-Benz Center.The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the battery is too weak
or discharged.XJump-start the vehicle ( Y page 313).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop, e.g. an authorized
Mercedes-Benz Center.The starter motor was exposed to a thermal load that was too high.XAllow the starter motor to cool down for approximately two
minutes.XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop, e.g. an authorized
Mercedes-Benz Center.Driving149Driving and parkingZ

obtained from oil companies, e.g. at gas
stations.
Refueling
Fuel filler flap
The fuel filler flap is unlocked or locked
automatically when you open or close the
vehicle with the SmartKey or using KEYLESS-
GO.
The position of the fuel filler cap is displayed
in the instrument cluster 8. The arrow
next to the filling pump indicates the side of
the vehicle.
:To open the fuel filler flap;To insert the fuel filler cap=Fuel type?Tire pressure table
Opening
XSwitch off the engine.XRemove the SmartKey from the ignition
lock.
KEYLESS-GO: open the driver’s door. This
switches the ignition to position 0, which
corresponds to having removed the
SmartKey. The driver’s door can be closed
again.XPress the fuel filler flap in the direction of
arrow :.
The fuel filler flap opens slightly.XOpen the fuel filler flap.XTurn the fuel filler cap counter-clockwise
and remove it.XInsert the fuel filler cap into the holder
bracket on the inside of filler flap ;.XCompletely insert the pump nozzle into the
filler neck and refuel.XOnly fill the tank until the pump nozzle
switches off.
! Overfilling the fuel tank could damage the
fuel system.
Closing
XReplace the fuel filler cap and turn it
clockwise. The fuel filler cap audibly
engages.XClose the fuel filler flap.
i If you drive with the fuel filler cap open,
the reserve fuel warning lamp flashes. In
addition, the ! (USA only) or ;
(Canada only) Check Engine warning lamp
may light up. A message appears in the
multifunction display ( Y page 228).
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 244).
i Close the fuel filler flap before locking the
vehicle. A locking pin otherwise prevents
the fuel filler flap from closing after the
vehicle has been locked.
Fuel filler flap emergency release
GWARNING
Avoid contact with the vehicle walls as they
may contain sharp edges. Otherwise, you
could injure yourself while releasing the fuel
filler flap.
The emergency release is located in the cargo
compartment behind the side trim on the
right-hand side, when viewed in the direction
of travel.
158RefuelingDriving and parking

automatic transmission shifts to P
automatically.
Using KEYLESS-GOXPress the Start/Stop button (Y page 145).
The engine stops and all the indicator
lamps in the instrument cluster go out.
i When the driver's door is closed, this
corresponds to SmartKey position 1. When
the driver's door is open, it corresponds to
SmartKey position 0 or "SmartKey
removed".
i If you use the Start/Stop button to switch
off the engine, the automatic transmission
shifts to N automatically. If you then open
the driver's or front-passenger door, the
automatic transmission shifts to P.
i In an emergency, the engine can be
turned off while the vehicle is in motion by
pressing and holding the Start/Stop button
for three seconds.
Parking brake
GWARNING
Engaging the parking brake while the vehicle
is in motion can cause the rear wheels to lock
up. You could lose control of the vehicle and
cause an accident. In addition, the vehicle's
brake lights do not light up when the parking
brake is engaged.
GWARNING
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it with
you, and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. Children could
release the parking brake and/or shift the
automatic transmission out of park position
P , either of which could result in an accident
and/or serious personal injury.
XTo apply: depress parking brake ; firmly.
When the engine is running, the $ (USA
only) or J (Canada only) indicator lamp
lights up in the instrument cluster.XTo release: depress the brake pedal and
keep it depressed.XPull release handle :.
When the ignition is switched on or the
engine is running, the $ (USA only) or
J (Canada only) indicator lamp goes out
in the instrument cluster.
Parking the vehicle for a long period
If you leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharge.
XConnect a trickle charger.
i You can obtain information about trickle
chargers from a qualified specialist
workshop, e.g. an authorized Mercedes-
Benz Center.
If you leave the vehicle parked for longer than
six weeks, the vehicle may suffer damage as
a result of lack of use.
XVisit a qualified specialist workshop and
seek advice.164ParkingDriving and parking

Wet roadsGWARNING
After driving in heavy rain for some time
without applying the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced. You have to depress the brake pedal
more firmly. Maintain a safe distance from
vehicles in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion.
Limited braking performance on salt
treated roads
GWARNING
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip, so that salt residues are removed
from the brake discs.
Servicing the brakes
! If the brake warning lamp lights up in the
instrument cluster and you hear a warning
tone even though the parking brake has
been released, the brake fluid level may be
too low. Observe additional warning
messages in the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked
immediately. Have this work carried out at
an authorized Mercedes-Benz Center.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. This work
should be carried out at an authorized
Mercedes-Benz Center.
Have the brake pads and brake fluid installed
or replaced at a qualified specialist workshop,
e.g. an authorized Mercedes-Benz Center.GWARNING
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that safe
braking is substantially impaired. This could
result in an accident.
! A function or performance test should
only be carried out on a 2-axle
dynamometer. If you are planning to have
the vehicle tested on such a dynamometer,
contact an authorized Mercedes-Benz
Center to obtain further information first.
Otherwise, you could damage the drive
train or the brake system.
! As the ESP ®
system operates
automatically, the engine and the ignition
must be switched off (SmartKey in position
0 or 1 in the ignition lock or Start/Stop
button in position 0 or 1) while the parking
brake is being tested on a brake
dynamometer (maximum 10 seconds).
Braking maneuvers triggered automatically
by ESP ®
may seriously damage the brake
system.
If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals by pressing firmly on the brake pedal
Driving tips167Driving and parkingZ

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

Useful information ............................198
Important safety notes ....................198
Displays and operation ....................198
Menus and submenus ......................201
Display messages ............................. 213
Warning and indicator lamps in the
instrument cluster ............................238197On-board computer and displays

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

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