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

Coolant (engine)Checking the level .........................285
Display message ............................ 225
Notes ............................................. 359
Temperature gauge ........................ 202
Cooling
see Climate control
Crash-responsive emergency
lighting ............................................... 119
Cruise control Cruise control lever .......................171
Deactivating ................................... 172
Display message ............................ 230
Driving system ............................... 170
Function/notes ............................. 170
Important safety notes ..................170
LIM indicator lamp .........................171
Setting a speed .............................. 172
Storing and maintaining current
speed ............................................. 171
Cup holder
Center console .............................. 263
Important safety notes ..................262
second row of seats ....................... 263
Second row of seats (armrest) .......264
third row of seats ........................... 264
Customer Assistance Center (CAC) ... 24
Customer Relations Department ....... 24
D
Dashboard see Cockpit
Date (on-board computer) ................ 206
Daytime running lamp mode see Daytime running lamps
Daytime running lamps
Display message ............................ 224
Switching on/off (on-board
computer) ...................................... 206
Switching on/off (switch) ..............115
DEF
Adding ........................................... 161
Display message ............................ 228
Delayed switch-off
Exterior lighting (on-board
computer) ...................................... 207
Interior lighting .............................. 208
Diesel particle filter .......................... 166
Digital speedometer Displaying ...................................... 202
Setting the unit (on-board
computer) ...................................... 205
DIRECT SELECT lever
see Automatic transmission
Display (cleaning instructions) ........ 292
Display messages Calling up (on-board computer) .....213
Driving systems ............................. 229
Engine ............................................ 225
General notes ................................ 213
Hiding (on-board computer) ...........213
Key ................................................ 236
KEYLESS-GO .................................. 236
Lights ............................................. 222
Safety systems .............................. 214
Service interval display ..................287
Tires ............................................... 231
Vehicle ........................................... 234
Distance recorder ............................. 202
see Odometer
see Trip odometer
Distance warning (warning lamp) .... 245
Distance warning function
(vehicles with DISTRONIC) Activating/deactivating (on-
board computer) ............................ 210
Notes ............................................... 68
DISTRONIC
Deactivating ................................... 178
Display message ............................ 230
Displays in the multifunction
display ........................................... 178
Driving tips .................................... 179
Important safety notes ..................173
Notes/function .............................. 173
Setting the specified minimum
distance ......................................... 177
Warning lamp ................................. 245
Door
Central locking/unlocking (key) ......72
Control panel ................................... 35
Important safety notes ....................79Index7

Convenience submenu ..................209
Displaying a service message ........287
Displaying the coolant
temperature ................................... 202
Displaying the outside
temperature ................................... 202
Display messages ..........................213
DISTRONIC menu .......................... 178
Factory settings ............................. 205
Important safety notes ..................198
Instrument cluster submenu ..........205
Lighting submenu .......................... 206
Menu overview .............................. 201
Message memory menu ................. 213
Navigation menu ............................ 204
Operating video DVD .....................204
Operation ....................................... 199
Selecting the language ..................206
Settings menu ............................... 205
Standard display ............................ 202
Status bar ...................................... 206
Telephone menu ............................ 211
Time/Date submenu .....................206
Trip computer menu ......................210
Vehicle submenu ........................... 208
Opening and closing the side trim
panels ................................................. 123
Operating system see On-board computer
Outside temperature
Calling up (on-board computer) .....202
Display ........................................... 198
Overhead control panel ...................... 34
Override feature Rear side windows ...........................63
P
Paint code number ............................ 353
Paintwork (cleaning instructions) ... 290
Panic alarm .......................................... 64
Panorama roof with power tilt/
sliding panel Opening/closing .............................. 91
Opening/closing the roller
sunblind ........................................... 91
Problem (malfunction) .....................92
Resetting ......................................... 92
Panorama sliding sunroof
Important safety notes ....................89
Parking
Important safety notes ..................163
Parking brake ................................ 164
Position of exterior mirror, front-
passenger side ............................... 111
Rear view camera .......................... 187
see Parking
see PARKTRONIC
Parking aid
see Exterior mirrors
see PARKTRONIC
Parking brake
Display message ............................ 217
Notes/function .............................. 164
see Parking brake
Parking lamps (changing bulbs) ...... 122
PARKTRONIC Deactivating/activating .................186
Driving system ............................... 184
Function/notes ............................. 184
Problem (malfunction) ...................187
Range of the sensors .....................184
Trailer towing ................................. 186
Warning display ............................. 185
Pedals ................................................. 165
Permanent four-wheel drive see 4MATIC (permanent four-
wheel drive)
Plastic trim (cleaning instructions) . 292
Power washers .................................. 289
Power windows see Side windows
PRE-SAFE ®
(Preventive occupant
safety system) Display message ............................ 218
Operation ......................................... 49
PRE-SAFE ®
Brake (vehicles with
DISTRONIC PLUS) Warning lamp ................................. 245
Preventive occupant safety
system
see PRE-SAFE ®
(Preventive
occupant safety system)
Product information ............................ 21
Program selector button .................. 153Index13

Opening/closing (automatically
from outside) ................................... 83
Opening/closing (from outside) .......82
Tail lamps
Display message ............................ 224
see Lights
Tank
see Fuel tank
Tank content
Fuel gauge ....................................... 29
Technical data
R 350 ............................................. 361
R 350 BlueTEC ............................... 360
Tires/wheels ................................. 347
TELEAID
Call priority .................................... 273
Display message ............................ 218
Downloading destinations
(COMAND) ..................................... 273
Emergency call .............................. 270
Important safety notes ..................269
Locating a stolen vehicle ...............275
MB info call button ........................272
Roadside Assistance button ..........272
Search & Send ............................... 274
Self-test ......................................... 270
System .......................................... 270
Vehicle remote unlocking ..............274
Telephone
Accepting a call ............................. 211
Display message ............................ 235
Menu (on-board computer) ............211
Number from the phone book ........ 212
Redialing ........................................ 212
Rejecting/ending a call .................212
Temperature
Coolant (on-board computer) ......... 202
Displaying the outside
temperature ................................... 202
Outside temperature ...................... 198
Setting (climate control) ................137
Theft deterrent locking system
Immobilizer ...................................... 68
Tilt/sliding sunroof
see Sliding sunroof
Time (on-board computer) ................ 206
TIREFIT kit .......................................... 299Tire pressure
Calling up (on-board computer) .....331
Checking manually ........................329
Display message ............................ 231
Maximum ....................................... 328
Notes ............................................. 327
Not reached (TIREFIT) ....................302
Pressure loss warning ....................329
Reached (TIREFIT) ..........................302
Recommended ............................... 325
Tire pressure monitoring system
Function/notes ............................. 331
Restarting ...................................... 333
Warning lamp ................................. 245
Tires
Aspect ratio (definition) .................345
Average weight of the vehicle
occupants (definition) ....................343
Bar (definition) ............................... 343
Characteristics .............................. 343
Checking ........................................ 323
Definition of terms .........................343
Direction of rotation ......................346
Display message ............................ 231
Distribution of the vehicle
occupants (definition) ....................346
DOT, Tire Identification Number
(TIN) ............................................... 342
DOT (Department of
Transportation) (definition) ............343
GAWR (Gross Axle Weight Rating)
(definition) ..................................... 344
GTW (Gross Trailer Weight)
(definition) ..................................... 344
GVW (Gross Vehicle Weight)
(definition) ..................................... 344
GVWR (Gross Vehicle Weight
Rating) (definition) .........................344
Important safety notes ..................322
Increased vehicle weight due to
optional equipment (definition) ......343
Kilopascal (kPa) (definition) ...........344
Labeling (overview) ........................339
Load bearing index (definition) ......345
Load index ..................................... 342
Load index (definition) ...................344
Maximum loaded vehicle weight
(definition) ..................................... 344Index17

iThe cooling with air dehumidification
function uses refrigerant R134a. This
coolant does not contain
chlorofluorocarbons, and therefore does
not damage the ozone layer.
Activating/deactivating
! If the cooling with air dehumidification
does not switch on, it is possible that the
climate control system has lost coolant.
Have the cooling with air dehumidification
checked at a qualified specialist workshop.
XTo activate: press the Á button.
The indicator lamp in the Á button lights
up.XTo switch off: press the Á button.
The indicator lamp in the Á button goes
out. The cooling with air dehumidification
function has a delayed switch-off feature.
Problems with the cooling with air
dehumidification function
If the indicator lamp in the Á button does
not go out when the function is activated, the
cooling with air dehumidification function is
deactivated due to a malfunction. You can no
longer switch on the cooling with air
dehumidification function.
XConsult a qualified specialist workshop.
Setting climate control to automatic
GWARNING
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
In automatic mode, the set temperature is
maintained automatically at a constant level.
The system automatically regulates the
temperature of the dispensed air, the airflow
and the air distribution.
Automatic mode will achieve optimal
operation if cooling with air dehumidification
is also activated. If desired, cooling with air
dehumidification can be deactivated.
Controlling the front climate control
using the front control panelXTurn the SmartKey to position 2 in the
ignition lock.XSet the desired temperature.XTo activate: press the à button.
The indicator lamp in the à button lights
up. Automatic air distribution and airflow
are activated.XTo deactivate: press the K or I
button.
The indicator lamp in the à button goes
out. Automatic airflow is deactivated and
the airflow is controlled according to the
level set. Automatic air distribution
remains activated.
or
XPress the Z, M , ¯ , \ , P ,
c or O button.
The indicator lamp in the à button goes
out. Automatic air distribution is
deactivated. Air distribution is controlled
according to the position set. Automatic
airflow remains activated.
Controlling the rear-compartment
climate control automatically using the
rear control panel
XTurn the SmartKey to position 2 in the
ignition lock.XSwitch on automatic climate control using
the front control panel.XSet the desired temperature.XTo activate: press the à button.
The indicator lamp in the à button lights
up. Automatic air distribution and airflow
are activated.136Operating the climate control systemClimate control

iResidual heat is deactivated
automatically:
R after about 30 minutes
R when the ignition is switched on
R if the battery voltage drops
R if the coolant temperature is too low
Setting the air vents
Important safety notes
GWARNING
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature). This
could cause burns or frostbite to unprotected
skin in the immediate area of the air vents.
Always keep sufficient distance between
unprotected parts of the body and the air
vents. If necessary, use the air distribution
adjustment to direct the air to air vents in the
vehicle interior that are not in the immediate
area of unprotected skin.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
R keep the air intake grille on the hood free
of blockages, such as ice, snow or leaves
R never cover the air vents or air intake grille
in the vehicle interior.
i For virtually draft-free ventilation, adjust
the sliders of the air vents to the center
position.
Setting the center air vents:Center air vent, left;Center air vent, right=Center vent thumbwheel, right?Center vent thumbwheel, leftXTo open/close: turn thumbwheels =
and ? up or down.
Setting the side air vents
XTo open/close: turn thumbwheel = up or
down.
i Side window defroster vent : is never
completely shut, even if side air vent ; is
shut.
Setting the air vents141Climate controlZ

ProblemPossible causes/consequences and M SolutionsVehicles with a
gasoline engine:
The engine is not
running smoothly and
is misfiring.There is a malfunction in the engine electronics or a mechanical
component of the engine management system.XOnly depress the accelerator pedal slightly.XHave the cause rectified immediately at a qualified specialist
workshop, e.g. an authorized Mercedes-Benz Center.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it.The coolant
temperature gauge
shows a value above
248 ‡ (120 †).The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.XStop as soon as possible and allow the engine and the coolant
to cool down.XCheck the coolant level ( Y page 285). Observe the warning
notes as you do so and add coolant if necessary.Automatic transmission
Important safety notes
GWARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
GWARNING
Keep in mind that turning off the engine alone
only will shift the automatic transmission into
neutral position N automatically.
Always shift the automatic transmission into
park position P before turning off the engine.
Otherwise the vehicle could roll away which
could result in an accident and/or serious
personal injury.
DIRECT SELECT lever
Overview of transmission positions
The DIRECT SELECT lever is on the right of the
steering column.
PPark position with parking lockRReverse gearNNeutralDDrive
i The DIRECT SELECT lever always returns
to its original position. The current
transmission position P, R , N or D appears
in the transmission position display
( Y page 151) in the multifunction display.
150Automatic transmissionDriving and parking

Please observe the following when towing a
trailer:
R To acquaint yourself with driving with a
trailer and with the resulting changes to
handling, you should practice cornering,
stopping and reversing in a traffic-free
location.
R Before driving, check:
- the trailer tow hitch
- the safety switch for braked trailers
- the safety chains
- the electrical connections
- the lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer features electronically
controlled brakes, pull away the vehicle/
trailer combination carefully, manually
brake using the brake controller, and check
the brakes for correct function.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
R If you couple up a trailer, regularly check
the cargo for secure fastening and make
sure that the trailer lamps and (if
applicable) the trailer brakes are
functioning correctly.
R Bear in mind that the handling will be less
stable when towing a trailer than when
driving without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that
the trailer can activate its own brakes. Then
increase the pressure on the brake pedal.R If the automatic transmission continues to
shift back and forth between two gears
when driving up or downhill, restrict the
shift range. Select shift range 4, 3, 2, or 1.
A lower gear and lower speed reduce the
risk of engine failure.
R When driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases
dramatically while the air-conditioning
system is switched on, switch off the air-
conditioning system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of your vehicle/trailer
combination, you will have to travel an
additional distance beyond the vehicle you
are overtaking before returning to the
previous lane.
Decoupling a trailer
GWARNING
Vehicles with AIRMATIC: While you are
coupling or decoupling a trailer, make sure
nobody locks or unlocks the vehicle and/or
opens or closes doors or the tailgate.
The vehicle's level could change and you
could endanger yourself and/or others as a
result.
Make sure that you do not operate the ADS
switch or the vehicle level control system
when coupling/decoupling the trailer.
XMake sure that the automatic transmission
is set to position P.XApply the vehicle's parking brake.Trailer towing193Driving 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

Display messagesPossible causes/consequences and M Solutions?
Coolant Stop car,
switch engine offThe coolant is too hot.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XMake sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.XWait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.XPay attention to the coolant temperature display.XIf the temperature increases again, visit a qualified specialist
workshop immediately.The poly-V-belt may have torn.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XWait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.XPay attention to the coolant temperature display.XVisit a qualified specialist workshop.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.
! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.
226Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions?The engine fan is defective.XAt coolant temperatures under 248 ‡ (120 †), drive to the next
qualified specialist workshop.XAvoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic.#The battery is not being charged.
Possible causes are:
R a defective alternator
R a torn poly-V-belt
R a malfunction in the electronicsXPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.XOpen the hood.XCheck whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
XConsult a qualified specialist workshop.
If the poly-V-belt is OK:
XVisit a qualified specialist workshop.#
Battery /
Alternator Stop
VehicleThe battery is defective.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.XEngage the parking brake.XConsult a qualified specialist workshop.4
Check engine oil
level at next
refuelingThe oil level is too low.XCheck the oil level ( Y page 283).XIf necessary, add engine oil ( Y page 284).XHave the engine checked for leaks if the engine oil needs to be
refilled more often than usual.
Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at http://www.mbusa.com (USA only).
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored.
Display messages227On-board computer and displaysZ