2012 MERCEDES-BENZ R-Class warning lights

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

GWARNING
Any device that you connect must have a
suitable plug and meet U.S. standards. Never
pull at a cable to disconnect a plug from a
115 V AC power socket. Never use a damaged
connection cable. The 115 V AC power socket
must never be connected to another 115 V
AC power source. Do not use a converter with
an earthed plug for the 115 V AC power
socket. This could cause serious injury to you
and/or other people.
GWARNING
If the 115V AC socket is damaged or torn out
of the trim, do not use or touch the 115V AC
socket. Using a 115V AC socket that is
damaged or torn out of the trim could cause
serious personal injury to you and/or others.
115 V socket : provides an alternating
voltage of 115 V, so that small electronic
devices can be connected. These devices,
such as games consoles, chargers and
laptops, together should not consume more
than a maximum of 150 W.
Requirements for operation of these devices:
R the plug of the electronic device must be
inserted fully into 115 V power socket :.
R the maximum wattage of the device to be
connected must not exceed 150 W.
R the on-board power supply is within a
permissible volt range.
R the 12 V sockets in the rear and the cargo
compartment are operational
( Y page 267).
XOpen flap =.XInsert the plug of the electronic device into
115 V power socket :.
Indicator lamp ; lights up.
If indicator lamp ; does not light up,
consult the section on malfunctions.XTo turn off: disconnect the plug from 115 V
power socket :.
Ensure that you do not pull on the cord.XClose flap =.
Possible causes of malfunction:
R the on-board power supply is not within a
permissible volt range.
R the temperature of the DC/AC converter is
temporarily too high.
R some small electronic devices have a
constant nominal power of less than
150 W, but a very high inrush current.
These devices will not work. If you connect
such a device, 115 V power socket : will
not supply it with power.
If indicator lamp ; still does not light up,
contact a specialist workshop, e.g. an
authorized Mercedes-Benz Center.
mbrace
Important safety notes
! A license agreement must exist in order
to activate the mbrace service. Ensure that
your system is activated and ready for use,
and press the E MB Info call button to
register. If any of the steps mentioned is
not carried out, the system may not be
activated.
If you have questions about the activation,
contact one of the following telephone
assistance services:
R USA: Mercedes-Benz Customer
Assistance Center under
1-888-990-9007
R Canada: Customer Service at
1-888-923-8367
Features269Stowing and featuresZ

XMake sure the vehicle is stationary and the
ignition is switched off.XTurn the SmartKey to position
2 (Y page 145) in the ignition lock.
Use the SmartKey instead of the Start/
Stop button on vehicles with KEYLESS-GO.XDepress and hold the brake pedal.XShift the automatic transmission to
position N.XRelease the brake pedal.XRelease the parking brake.XSwitch off the ignition and leave the
SmartKey in the ignition lock.
! Make sure that:
R the side windows and the sliding sunroof
are fully closed.
R the ventilation/heating is switched off
(the OFF button has been pressed).
R the windshield wiper switch is in position
0 .
Otherwise, the vehicle might be damaged.
After using an automatic car wash, wipe off
wax from the windshield and the wiper
blades. This will prevent smears and reduce
wiping noises caused by residue on the
windshield.
Washing by hand
Carefully remove all deposits of road salt as
soon as possible when driving in winter.
Also, clean the insides of the wheels when
washing the underbody of the vehicle.
XDo not use hot water and do not wash the
vehicle in direct sunlight.XUse a soft car sponge for cleaning.XUse a gentle cleaning agent, e.g. a
Mercedes-Benz approved car shampoo.XWash down the vehicle with a gentle water
jet.XDo not point the water jet directly at the air
inlets.XUse plenty of water and rinse the sponge
frequently.XRinse the vehicle with clean water and dry
it thoroughly with a chamois.XDo not allow the cleaning agent to dry on
the paintwork.
Power washers
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.
! Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about
the correct distance is available from the
equipment manufacturer.
Move the power washer nozzle around
when cleaning your vehicle.
Do not aim directly at any of the following:
R tires
R door gaps, roof gaps, joints etc.
R electrical components
R battery
R connectors
R lights
R seals
R trim elements
R ventilation slots
Damaged seals or electrical components
can lead to leaks or failures.
Cleaning the wheels
! Do not use acidic wheel cleaning products
to remove brake dust. This could damage
wheel bolts and brake components.
! Do not park the vehicle for an extended
period straight after cleaning it, particularly
after having cleaned the wheels with wheel
cleaner. Wheel cleaners could cause
increased corrosion of the brake discs and
brake pads/linings. For this reason, you
should drive for a few minutes after
Care289Maintenance and careZ

Cleaning the windowsGWARNING
Before cleaning the windshield or wiper
blades, switch off the windshield wipers and
remove the SmartKey from the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button repeatedly until all
indicator lamps in the instrument cluster have
gone out. The windshield wipers could
otherwise move and injure you.
XClean the inside and outside of the
windows with a damp cloth and a cleaning
agent that is recommended and approved
by Mercedes-Benz.
! Do not use dry cloths, abrasive products,
solvents or cleaning agents containing
solvents to clean the inside of the windows.
Do not touch the insides of the windows
with hard objects, e.g. an ice scraper or
ring. There is otherwise a risk of damaging
the windows.
! Clean the water drainage channels of the
windshield and the rear window at regular
intervals. Deposits such as leaves, petals
and pollen may under certain
circumstances prevent water from draining
away. This can lead to corrosion damage
and damage to electronic components.
Cleaning the wiper blades
GWARNING
Before cleaning the windshield or wiper
blades, switch off the windshield wipers and
remove the SmartKey from the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button repeatedly until all
indicator lamps in the instrument cluster have
gone out. The windshield wipers could
otherwise move and injure you.
! Do not pull the wiper blade. Otherwise,
the wiper blade could be damaged.
! Do not clean wiper blades too often and
do not rub them too hard. Otherwise, the
graphite coating could be damaged. This
could cause wiper noise.XFold the wiper arms away from the
windshield.XCarefully clean the wiper blades with a
damp cloth.XFold the windshield wipers back again
before switching on the ignition.
! Hold the wiper arm securely when folding
back. The windshield could be damaged if
the wiper arm smacks against it suddenly.
Cleaning the exterior lighting
XClean the plastic lenses of the exterior
lights with a wet sponge and a mild cleaning
agent, e.g. Mercedes-Benz car shampoo or
cleaning cloths.
! Only use cleaning agents or cleaning
cloths which are suitable for plastic light
lenses. Unsuitable cleaning agents or
cleaning cloths could scratch or damage
the plastic light lenses.
Cleaning the sensors
XClean sensors : of the driving systems
with water, car shampoo and a soft cloth.Care291Maintenance and careZ