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

1, 2, 3 ...
115 V socket ...................................... 268
12 V socket see Sockets
4ETS (Electronic Traction System) .... 66
A
ABS (Anti-lock Braking System) Display message ............................ 214
Function/notes ................................ 65
Important safety notes ....................65
Warning lamp ................................. 240
Activating/deactivating cooling
with air dehumidification ................. 135
Active service system PLUS see ASSYST PLUS service interval
display
Adaptive Damping System (ADS) ..... 181
Additives (engine oil) ........................ 358
Adjusting the armrest (2nd row of
seats) .................................................. 102
ADS (Adaptive Damping System) ..... 181
Air bags Display message ............................ 220
Front air bag (driver, front
passenger) ....................................... 42
Important safety notes ....................40
Safety guidelines ............................. 39
Side impact air bag ..........................42
Window curtain air bag ....................43
Air-conditioning system
see Climate control
Air filter (display message) .............. 228
AIRMATIC (display message) ............ 229
AIRMATIC package ............................ 180
Air pressure see Tire pressure
Air vents
Important safety notes ..................141
Rear ............................................... 142
Setting ........................................... 141
Setting the center air vents ...........141
Setting the side air vents ...............141
Alarm system
see ATA (Anti-Theft Alarm system)
Anti-lock Braking System
see ABS (Anti-lock Braking System)
Anti-Theft Alarm system
see ATA (Anti-Theft Alarm system)
Anti-theft system
ATA (Anti-Theft Alarm system) .........69
Ashtray ............................................... 265
ASSYST PLUS see ASSYST PLUS service interval
display
ATA (Anti-Theft Alarm system)
Activating/deactivating ...................69
Function ........................................... 69
Switching off the alarm ....................69
Audio menu (on-board computer) .... 203
Audio system see separate operating instructions
Authorized Mercedes-Benz Center
see Qualified specialist workshop
AUTO lights
Display message ............................ 225
see Lights
Automatic headlamp mode .............. 115
Automatic transmission Automatic drive program ...............154
Changing gear ............................... 152
DIRECT SELECT lever .....................150
Display message ............................ 234
Driving tips .................................... 153
Emergency running mode ..............156
Kickdown ....................................... 153
Problem (malfunction) ...................156
Program selector button ................153
Pulling away ................................... 147
Shift ranges ................................... 154
Starting the engine ........................146
Steering wheel paddle shifters ......153
Trailer towing ................................. 153
Transmission position display ........151
Transmission positions ..................152
Automatic transmission
emergency mode ............................... 1564Index

Problems with the transmissionProblemPossible causes/consequences and M SolutionsThe transmission has
problems shifting gear.The transmission is losing oil.XHave the transmission checked at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center,
immediately.The acceleration ability
is deteriorating.
The transmission no
longer changes gear.The transmission is in emergency mode.
It is only possible to shift into second gear and reverse gear.XStop the vehicle.XShift the transmission to position P.XSwitch off the engine.XWait at least 10 seconds before restarting the engine.XShift the transmission to position D or R.
If D is selected, the transmission shifts into second gear; if R is
selected, the transmission shifts into reverse gear.XHave the transmission checked at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center,
immediately.Transfer case
The vehicle has permanent 4-wheel drive
(4MATIC). Power is always transmitted to
both axles.
! Performance tests may only be carried
out on a 2-axle dynamometer. The brake
system or transfer case could otherwise be
damaged. Contact a qualified specialist
workshop for a performance test.
Mercedes-Benz recommends that you use
an authorized Mercedes-Benz Center for
this purpose.
! If the parking brake is being tested on a
brake dynamometer, the ignition must be
switched off (SmartKey or Start/Stop
button in position 0 or 1), as ESP ®
will
otherwise automatically intervene. The test
must last a maximum of 10 seconds. The
brake system could otherwise be damaged.Refueling
Important safety notes
GWARNING
Gasoline and diesel fuels are highly flammable
and poisonous. They burn violently and can
cause serious injury.
Never allow sparks, flames or smoking
materials near gasoline or diesel fuel!
Turn off the engine before refueling.
Whenever you are around gasoline or diesel
fuel, avoid inhaling fumes and any skin or
clothing contact. Extinguish all smoking
materials.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging your
health.
GWARNING
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gasoline
156RefuelingDriving and parking

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

damage to the engine or the catalytic
converter. Have excess oil siphoned off.
For further information on engine oil, see
( Y page 358).XReplace cap : on the filler neck and
tighten clockwise.
Ensure that the cap locks into place
securely.
Checking and adding other service
products
Checking the coolant level
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position
2 (Y page 145) in the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 145).XCheck the coolant temperature gauge in
the multifunction display.
The coolant temperature must be below
158 ‡ (70 †).GWARNING
In order to avoid any potentially serious burns:
R use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system, or
if the coolant temperature display indicates
that the coolant is overheated.
R do not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158 ‡ (70 †). Allow the engine to
cool down before removing the cap. The
coolant reservoir contains hot fluid and is
under pressure.
R using a rag, slowly turn the cap
approximately 1
/ 2 turn to relieve excess
pressure. If opened immediately, scalding
hot fluid and steam will be blown out under
pressure.
R do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts.XSlowly turn cap : half a turn counter-
clockwise and allow excess pressure to
escape.XTurn cap : further counter-clockwise and
remove it.
If the coolant is at the level of marker bar
= in the filler neck when cold, there is
enough coolant in coolant expansion
tank ;.
If the coolant is approximately 0.6 in
(1.5 cm) above marker bar = in the filler
neck when warm, there is enough coolant
in coolant expansion tank ;.XIf necessary, add coolant that has been
tested and approved by Mercedes-Benz.XReplace cap : and turn it clockwise as far
as it will go.
For further information on coolant, see
( Y page 359).
Windshield washer system and
headlamp cleaning system
The washer fluid reservoir is used for both the
windshield washer system and the headlamp
cleaning system.
i Vehicle components and their service
products must match. You should,
Engine compartment285Maintenance and careZ

! When cleaning the sensors with a power
washer, maintain a distance between the
vehicle and the nozzle of the power washer
of at least 11.8 in (30 cm). Information
about the correct distance is available from
the equipment manufacturer.
Cleaning the rear view cameraXUse clear water and a soft cloth to clean
camera lens :.
!
Do not clean the camera lens and the area
around the rear view camera with a power
washer.
Cleaning the exhaust tail pipes
Impurities combined with the effects of road
grit and corrosive environmental factors may
cause flash rust to form on the surface. You
can restore the original shine of the exhaust
tail pipe by cleaning it regularly, especially in
winter and after washing.
! Do not clean the exhaust tail pipes with
alkaline-based cleaning agents, such as
wheel cleaner.
XClean the exhaust tail pipes with a chrome
care product tested and approved by
Mercedes-Benz.Interior care
Cleaning the displayXBefore cleaning the display, make sure that
it is switched off and has cooled down.XClean the display surface using a
commercially-available microfiber cloth
and TFT/LCD display cleaner.XDry the display surface using a dry
microfiber cloth.
! For cleaning, do not use any of the
following:
R alcohol-based thinner or gasoline
R abrasive cleaning agents
R commercially-available household
cleaning agents
These may damage the display surface. Do
not put pressure on the display surface
when cleaning. This could lead to
irreparable damage to the display.
Cleaning the plastic trim
GWARNING
When cleaning the steering wheel boss and
dashboard, do not use cockpit sprays or
cleaning agents containing solvents. Cleaning
agents containing solvents cause the surface
to become porous, and as a result, plastic
parts may break away and be thrown around
the interior when an air bag is deployed, which
may result in severe injuries.
! Do not affix the following to plastic
surfaces:
R stickers
R films
R scented oil bottles or similar items
You can otherwise damage the plastic.
! Do not allow cosmetics, insect repellent
or sunscreen to come into contact with the
plastic trim. This maintains the high-quality
look of the surfaces.
292CareMaintenance and care

Mounting a new wheelGWARNING
Always replace wheel bolts that are damaged
or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be
repaired immediately. Do not continue to
drive under these circumstances! Contact an
authorized Mercedes-Benz Center or call
Roadside Assistance.
Incorrect wheel bolts or improperly tightened
wheel bolts can cause the wheel to come off.
This could cause an accident. Make sure to
use the correct wheel bolts.
GWARNING
Only use genuine Mercedes-Benz wheel bolts.
Other wheel bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise, the vehicle could
fall off the jack.
:Wheel bolts for 18", 19" and 20" wheels2Wheel bolts for the collapsible spare
wheel
! Always use wheel bolts ; to mount the
collapsible spare wheel. Using other wheel
bolts to mount the collapsible spare wheel
could damage the brake system.
GWARNING
Make sure to use the original length wheel
bolts when remounting the original wheel
after it has been repaired.
XClean the wheel and wheel hub contact
surfaces.
! To prevent damage to the paintwork, hold
the wheel securely against the wheel hub
while screwing in the first wheel bolt.
XSlide the emergency spare wheel onto the
alignment bolt and push it on.XTighten the wheel bolts until they are
finger-tight.XUnscrew the alignment bolt.XTighten the last wheel bolt until it is finger-
tight.XInflate the collapsible spare wheel
( Y page 307).
Inflating the collapsible spare wheel
GWARNING
Inflate the collapsible spare wheel only after
the wheel is properly attached.
Inflate the collapsible spare wheel using the
tire inflation compressor before lowering the
vehicle.
Your vehicle is equipped with one of two tire
inflation compressors:
R Version 1: tire inflation compressor with a
pressure gauge on the air hose
R Version 2: tire inflation compressor with
an integrated pressure gauge
The following description applies to both
versions. Differences in the way they are used
will be explained in detail.
Flat tire307Breakdown assistanceZ

Rim
This is the part of the wheel on which the tire
is mounted.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum permissible axle
weight. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side.
Tire speed rating
The tire speed rating is part of the tire
identification. It specifies the speed range for
which the tire is approved.
GTW (Gross Trailer Weight)
The GTW is the weight of a trailer including
the weight of the load, luggage, accessories
etc. on the trailer.
GVW (Gross Vehicle Weight)
The gross vehicle weight comprises the
weight of the vehicle including fuel, tools, the
spare wheel, accessories installed,
occupants, luggage and the drawbar
noseweight if applicable. The gross vehicle
weight must not exceed the gross vehicle
weight rating GVWR as specified on the
vehicle identification plate on the B pillar on
the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of the curb
weight of the vehicle, the weight of the
accessories, the total load limit and the
weight of the optional equipment installed at
the factory.
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa is the
equivalent of 1 psi. Another unit for tire
pressure is bar. There are 100 kilopascals
(kPa) to 1 bar.
Load index
In addition to the load bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifies the load bearing
capacity more precisely.
Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of fuel, oil and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximum load rating
The maximum load rating in kilograms or
pounds is the maximum weight for which a
tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
344Definition of terms for tires and loadingWheels and tires

Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the
tires from oil, grease, gasoline and diesel.
Cleaning the wheels
GWARNING
Do not use power washers with circular-jet
nozzles (dirt grinders) to clean your vehicle, in
particular the tires. You could otherwise
damage the tires and cause an accident.
Wheel and tire combinations
Please bear the following in mind
! For safety reasons, Mercedes-Benz
recommends that you only use Tires and
wheels which have been approved by
Mercedes-Benz specifically for your
vehicle.
These tires have been specially adapted for
use with the control systems, such as ABS
or ESP ®
, and are marked as follows:
R MO = Mercedes-Benz Original
R MOE = Mercedes-Benz Original Extended
(tires featuring run-flat characteristics)
R MO1 = Mercedes-Benz Original (only
certain AMG tires)
Mercedes-Benz Original Extended tires
may only be used on wheels that have been
specifically approved by Mercedes-Benz.
Only use tires, wheels or accessories
tested and approved by Mercedes-Benz.
Certain characteristics, e.g. handling,
vehicle noise emissions or fuel
consumption, may otherwise be adversely
affected. In addition, when driving with a
load, tire dimension variations could cause
the tires to come into contact with the
bodywork and axle components. This could
result in damage to the tires or the vehicle.
Mercedes-Benz accepts no liability for
damage resulting from the use of tires,
wheels or accessories other than those
tested and approved.
Further information about tires, wheels and
approved combinations can be obtained
from any authorized Mercedes-Benz
Center.
i The Tire and Load Information placard
with the recommended tire pressures is
attached to the B-pillar on the driver's side.
Further information about driving at high
speeds or driving with vehicle loads that are
lighter than the maximum vehicle load can
be found in the tire pressure table on the
inside of the fuel filler flap. Check tire
pressures regularly, and only when the tires
are cold. Comply with the maintenance
recommendations of the tire manufacturer
in the vehicle document wallet.
For further information on the recommended
tire inflation pressure and on tire pressures
for specific driving conditions, see
( Y page 325).
i Notes on the vehicle equipment – always
equip the vehicle:
R with tires of the same size on a given axle
(left/right)
R with the same type of tires at a given time
(summer tires, winter tires, MOExtended
tires)
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from an
authorized Mercedes-Benz Center.
i On the following pages, you can find
information on approved wheel rims and
tire sizes for equipping your vehicle with
winter tires. Winter tires are not available
from the factory as standard equipment or
optional extras.Wheel and tire combinations347Wheels and tiresZ

Fuel
Important safety notesGWARNING
Gasoline and diesel fuels are highly flammable
and poisonous. They burn violently and can
cause serious injury.
Never allow sparks, flames or smoking
materials near gasoline or diesel fuel!
Turn off the engine before refueling.
Whenever you are around gasoline or diesel
fuel, avoid inhaling fumes and any skin or
clothing contact. Extinguish all smoking
materials.
Direct skin contact with fuels and the
inhalation of fuel vapors are damaging your
health.
Premium-grade unleaded gasoline
! To ensure the longevity and full
performance of the engine, only premium-
grade unleaded gasoline must be used.
If no premium-grade unleaded gasoline is
available and regular unleaded gasoline
must be used, observe the following
precautions:
R only fill the fuel tank to half full with
regular unleaded gasoline and fill the rest
with premium-grade unleaded gasoline
as soon as possible.
R do not drive at the maximum speed.
R avoid sudden acceleration.
R when the vehicle is carrying a light load,
e.g. two passengers without luggage, do
not allow the engine to rev above
3000 rpm.
R when the vehicle is fully loaded or in
mountainous terrain, do not depress the
accelerator pedal further than ⅔ of the
pedal travel.
Fuel requirements
Gasoline engines
Use only premium-grade unleaded gasoline.
The octane number should be at least 91.
Details can be found on the gas pump. The
octane number is the average value of the
Research Octane Number (RON) and the
Motor Octane Number (MON): (RON +
MON) / 2, also known as knock resistance.
Reformulated Gasoline (RFG) and/or
unleaded gasoline with additives can be used
if the concentration of the additives in the fuel
does not exceed 10%, e.g.:
R Ethanol
R TAME
R ETBE
R IPA
R TBA
For MTBE, the concentration should not
exceed 15%.
The concentration of methanol in gasoline
including other additives must not exceed 3%.
Using mixtures of methanol and ethanol is not
permitted. Gasohol, a mixture of 10% ethanol
and 90% unleaded gasoline, can be used.
All of these mix fuels must fulfill the fuel
requirements, e.g.:
R knock resistance
R boiling point
R vapor pressure
Diesel engines – Important safety notes
! Only use commercially available ULTRA-
LOW SULFUR DIESEL FUEL (ULSD, 15 ppm
MAXIMUM SULFUR) that meets the
ASTM D975 standard. Failure to use
ULTRA-LOW SULFUR DIESEL FUEL (ULSD)
can severely damage the vehicle's exhaust
gas aftertreatment system.
! Do not fill the tank with gasoline. Do not
blend diesel fuel with gasoline or kerosene.
Otherwise, the fuel system and the engine
could be damaged.
356Service products and capacitiesTechnical data