2012 MERCEDES-BENZ R-Class Lights

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

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 language
The Language: function allows you to select
the language for the instrument cluster.
XPress V or U on the steering wheel
to select the Settings menu.XPress the & button to select submenus.XPress W or X to select the
Instrument cluster submenu.XPress & to select Language .XPress the W or X button to select the
desired language.XPress the &, V or U button to
select a different display.
Selecting the status line display
XPress V or U on the steering wheel
to select the Settings menu.XPress the & button to select submenus.XPress W or X to select the
Instrument cluster submenu.XPress & to select Status line
display .XPress W or X to select the display in
the status line: speed ( Speed) or outside
temperature ( Outside temp. ).
The selected display now appears
constantly in the lower multifunction
display. When you scroll through the
Standard display menu (Y page 202), you
will see the display you have not selected.XPress the &, V or U button to
select a different display.
Time/date
This submenu is only available on vehicles
with no navigation module. To set the time
and the date for vehicles with a navigation
module, see the separate operating
instructions.
In the Time/date submenu, you can set the
time and date.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
Time/date submenu.XTo set the time: press & to select
Clock Set Hour or Clock Set
Minute(s) .
or
XTo set the date: press & to select
Date Set Day , Date Set Month or Date
Set Year .XPress W or X to set a value.XPress the &, V or U button to
select a different display.
Lights
Switching the daytime running lamps on/
off
This function is not available in Canada.
If you have activated the Daytime Running
Lights function and the light switch is in the
$ or à position, the daytime running
lamps are automatically switched on when
the engine is running.
In the dark, the following also light up:
R the low-beam headlamps
R the parking lamps
R the tail lamps
R the license plate lamp
R the side marker lamps
On vehicles with daytime running lamps, the
factory setting is On
XSwitch off the engine.XPress V or U on the steering wheel
to select the Settings menu.XPress the & button to select submenus.206Menus and submenusOn-board computer and displays

Display messagesPossible causes/consequences and M Solutions$ (USA
only) ! (Canada
only)
Release Parking
BrakeYou are driving with the parking brake applied. A warning tone also
sounds.XRelease the parking brake$ (USA
only) J (Canada
only)
Check Brake Fluid
LevelGRisk of accident
There is not enough brake fluid in the brake fluid reservoir.
Additionally, the red $ (USA only)/ J (Canada only)
warning lamp lights up in the instrument cluster and a warning
tone sounds.
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.XDo not add brake fluid. This will not correct the malfunction.GWARNING
Driving with the message Check Brake Fluid Level displayed can result in an accident. Have
your brake system checked immediately.
Do not add brake fluid before checking the brake system. Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine parts and the brake fluid catching fire. You can be
seriously burned.
Display messages217On-board computer and displaysZ

GWARNING
If the 42 indicator lamp remains lit with an adult occupant on the front-passenger
seat even after performing the above corrective steps, do not have any passenger use the front-
passenger seat until the system has been repaired.
Lights
i Display messages about LEDs:
This display message will only appear if all LEDs have failed.
Display messagesPossible causes/consequences and M Solutionsb
Low Beam Left
or Low Beam RightThe left or right-hand low-beam headlamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 119).
or
XVisit a qualified specialist workshop.b
Trailer Tail Lamp
Left or Trailer
Tail Lamp RightThe left or right-hand trailer tail lamp is faulty.XCheck whether you are permitted to change the bulb yourself.
or
XVisit a qualified specialist workshop.b
Trailer Turn
Signal Left or
Trailer Turn
Signal RightThe left or right-hand trailer turn signal lamp is defective.XCheck whether you are permitted to change the bulb yourself.
or
XVisit a qualified specialist workshop.b
Trailer Brake LampThe trailer brake lamp is defective.XCheck whether you are permitted to change the bulb yourself.
or
XVisit a qualified specialist workshop.b
Turn Signal Rear
Left or Turn Signal
Rear RightThe rear left-hand or rear right-hand turn signal is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 119).
or
XVisit a qualified specialist workshop.222Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M Solutionsb
AUTO Light
InoperativeThe light sensor is defective.XVisit a qualified specialist workshop.
USA only:
XSwitch off the daytime running lamps in the on-board computer
( Y page 206).XSwitch the lights on and off using the light switch.b
Switch Off LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to $ or à .
or
XIf the rear fog lamp is switched on: press the light switch in to
the stop.
Engine
Display messagesPossible causes/consequences and M Solutions+
Top Up Coolant See
Operator's ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 285).XIf the coolant needs to be refilled more often than usual, have
the engine coolant system checked at a qualified specialist
workshop.GWARNING
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! The coolant level is too low. Avoid making long journeys with too little coolant in the cooling
system. The engine will otherwise be damaged.
The display messages and the corresponding symbol that indicate that the coolant level is
too low must not be ignored.
Display messages225On-board computer and displaysZ

Warning and indicator lamps in the instrument cluster
Seat belts
ProblemPossible causes/consequences and M Solutions7
After starting the
engine, the red seat
belt warning lamp lights
up for six seconds.The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.XFasten your seat belt ( Y page 51).7
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tone sounds
for up to six seconds.GRisk of injury
The driver's seat belt is not fastened.
XFasten your seat belt ( Y page 51).
The warning tone ceases.7
The red seat belt
warning lamp lights up
after the engine starts,
as soon as the driver's
or the front-passenger
door is closed.GRisk of injury
The driver or front passenger has not fastened their seat belt.
XFasten your seat belt ( Y page 51).
The warning lamp goes out.GRisk of injury
There are objects on the front-passenger seat.
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out.238Warning and indicator lamps in the instrument clusterOn-board computer and displays

EngineProblemPossible causes/consequences and M Solutions! (USA only)
; (Canada only)
The yellow Check
Engine warning lamp
lights up while the
ignition is switched on
with the engine
running.There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with a gasoline engine)
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.XHave the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you are required by law to immediately visit a
qualified specialist workshop as soon as the yellow Check
Engine warning lamp lights up. If in doubt, check whether such
legal regulations apply in the state/province in which you are
currently driving.
Vehicles with a diesel engine: the fuel tank has been run dry
( Y page 160).XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked.The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the !
(USA only)/ ;
(Canada only) yellow
Check Engine warning
lamp may light up.The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.XObserve the additional display messages in the multifunction
display.XCheck that the fuel filler cap is correctly closed.XIf the fuel filler cap is not correctly closed: close the fuel filler
cap.XIf the fuel filler cap is closed: visit a qualified specialist
workshop.The yellow reserve fuel
warning lamp lights up
while the engine is
running.The fuel level has dropped into the reserve range.XRefuel at the nearest gas station.244Warning and indicator lamps in the instrument clusterOn-board computer and displays

Driving systemsProblemPossible causes/consequences and M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion. A warning tone
also sounds.GRisk of accident
The warning is issued if you approach a stationary vehicle or a
vehicle driving ahead of you at too high a speed.
XBe prepared to brake immediately.XPay careful attention to the traffic situation. You may have to
brake or take evasive action.
More information about DISTRONIC (Y page 173) and the distance
warning signal ( Y page 68).
Tires
ProblemPossible causes/consequences and M Solutionsh
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.GRisk of accident
The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XObserve the additional display messages in the multifunction
display.XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 331).XIf necessary, change a wheel ( Y page 346).h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
60 seconds and then
remains lit.The tire pressure monitor is defective.XObserve the additional display messages in the multifunction
display.XVisit a qualified specialist workshop.GWARNING
Each tire, including the spare (if provided), should be checked every other week when cold and
inflated to the inflation pressure recommended by the vehicle manufacturer on the Tire and
Loading Information placard on the driver's door B-pillar or, if available, the tire inflation pressure
label on the inside of the fuel filler flap. If your vehicle has tires of a different size than the size
Warning and indicator lamps in the instrument cluster245On-board computer and displaysZ