instrument cluster MERCEDES-BENZ R-Class 2012 W251 Service Manual

ProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running.GRisk of accident
ABS (Anti-lock Brake System) is deactivated due to a malfunction.
ESP ®
(Electronic Stability Program), BAS (Brake Assist),
PRE-SAFE ®
, hill start assist and ESP ®
trailer stabilization, for
example, are therefore also deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic
transmission, will not be available.
!
The yellow ABS warning
lamp is lit while the
engine is running.GRisk of accident
ABS is temporarily unavailable. ESP ®
, BAS, EBD (electronic brake
force distribution), PRE-SAFE ®
, hill start assist and ESP ®
trailer
stabilization, for example, are therefore also unavailable.
Self diagnosis is not yet complete.
or
For example, the on-board voltage may be insufficient.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XCarefully drive a suitable distance making slight steering
movements at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.240Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds.GRisk of accident
EBD is faulty. Therefore, ABS, BAS, PRE-SAFE ®
, hill start assist and
ESP ®
trailer stabilization, for example, are also not available due
to a malfunction.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.$ (USA only)
J (Canada only)
֌!
The red brake warning
lamp, the yellow ESP ®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running.GRisk of accident
ABS and ESP ®
are faulty. As a result other systems, such as, BAS,
EBD, PRE-SAFE ®
, hill start assist and ESP ®
trailer stabilization...,
may also be unavailable due to a malfunction.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.÷
The yellow ESP ®
warning lamp flashes
while the vehicle is in
motion.GRisk of accident
ESP ®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC is deactivated.
XOnly depress the accelerator pedal as far as necessary when
pulling away.XRelease the accelerator pedal while the vehicle is in motion.XAdapt your driving style to suit the road and weather conditions.XDo not deactivate ESP ®
.
For exceptions: ( Y page 66).Warning and indicator lamps in the instrument cluster241On-board computer and displaysZ

ProblemPossible causes/consequences and M Solutions÷
The yellow ESP ®
warning lamp flashes
while the vehicle is in
motion.At least one wheel is spinning and the electronic traction system
is deactivated to prevent the brakes on the drive wheels from
overheating.XObserve the additional display messages in the multifunction
display.
The electronic traction system switches back on again as soon as
the brakes have cooled down.
The display message disappears and the ÷ warning lamp goes
out.
å
The yellow ESP ®
OFF
warning lamp is lit while
the engine is running.GRisk of accident
ESP ®
and ESP ®
trailer stabilization are deactivated. ESP ®
will not
stabilize the vehicle if it starts to skid or if a wheel starts to spin.
XReactivate ESP ®
.
For exceptions: ( Y page 66).XAdapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
XHave ESP ®
checked at a qualified specialist workshop.֌
The yellow ESP ®
and
ESP ®
OFF warning
lamps are lit while the
engine is running.GRisk of accident
ESP ®
, BAS, PRE-SAFE ®
, hill start assist and ESP ®
trailer
stabilization are not available due to a malfunction. ESP ®
will not
stabilize the vehicle if it starts to skid or if a wheel starts to spin.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.242Warning and indicator lamps in the instrument clusterOn-board computer and displays

ProblemPossible causes/consequences and M Solutions$ (USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the vehicle is
moving. A warning tone
also sounds.You are driving with the parking brake applied.XRelease the parking brake
The warning lamp goes out and the warning tone ceases.+
The red SRS warning
lamp is lit while the
engine is running.GRisk of injury
The restraint systems are malfunctioning. The air bags or ETDs
may either be triggered unintentionally or, in the event of an
accident, not be triggered at all.
XDrive on carefully.XVisit a qualified specialist workshop immediately.GWARNING
In the event a malfunction of the SRS is indicated as outlined above, the SRS may not be
operational.
For your safety, we strongly recommend that you contact an authorized Mercedes-Benz Center
immediately to have the system checked. Otherwise the SRS may not be activated when needed
in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and
unnecessarily which could also result in injury.
Warning and indicator lamps in the instrument cluster243On-board computer and displaysZ

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

indicated on the Tire and Loading Information placard or, if available, the tire inflation pressure
label, you should determine the proper tire inflation pressure for those tires.
As an added safety feature, your vehicle has been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pressure warning lamp when one or more of your tires
are significantly underinflated. Accordingly, when the low tire pressure warning lamp illuminates,
you should stop and check your tires as soon as possible, and inflate them to the proper pressure.
Driving on a significantly underinflated tire causes the tire to overheat and can lead to tire failure.
Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling
and stopping ability. Please note that the TPMS is not a substitute for proper tire maintenance,
and it is the driver's responsibility to maintain correct tire pressure, even if underinflation has
not reached the level to trigger illumination of the TPMS low tire pressure warning lamp.
Your vehicle has also been equipped with a TPMS malfunction indicator to indicate when the
system is not operating properly. The TPMS malfunction indicator is combined with the low tire
pressure warning lamp. When the system detects a malfunction, the warning lamp will flash for
approximately one minute and then remain continuously illuminated. This sequence will continue
upon subsequent vehicle start-ups as long as the malfunction exists. When the malfunction
indicator is lit, the system may not be able to detect or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of reasons, including the installation of incompatible
replacement or alternate tires or wheels on the vehicle that prevent the TPMS from functioning
properly. Always check the TPMS malfunction warning lamp after replacing one or more tires or
wheels on your vehicle to ensure that the replacement or alternate tires and wheels allow the
TPMS to continue to function properly.246Warning and indicator lamps in the instrument clusterOn-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).
Engine compartment
Hood
Opening the hood
GWARNING
Do not pull the release lever while the vehicle
is in motion. Otherwise, the hood could be
forced open by passing air flow.
This could cause the hood to come loose and
injure you and/or others.
GWARNING
Do not open the hood when the engine is
overheated. You could be seriously injured.
Observe the coolant temperature display to
determine whether the engine may be
overheated. If you see flames or smoke
coming from the engine compartment, move
away from the vehicle. Wait until the engine
has cooled. If necessary, call the fire
department.
GWARNING
There is a risk of injury if the hood is open,
even if the engine is not running.
Some engine components can become very
hot.
To avoid the risk of burns, only touch those
components described in the Operator's
Manual and observe the relevant safety notes.
GWARNING
To help prevent personal injury, stay clear of
moving parts when the hood is open and the
engine is running.
The radiator fan may continue to run for
approximately 30 seconds or may even
restart after the engine has been turned off.
Stay clear of fan blades.
GWARNING
Vehicles with gasoline engine:
The engine is equipped with a transistorized
ignition system. Because of the high voltage
it is dangerous to touch any components
(ignition coils, spark plug sockets, diagnostic
socket) of the ignition system
R with the engine running
R while starting the engine
R when the ignition is switched on and the
engine is turned manually
GWARNING
Vehicles with diesel engine:
The engine is equipped with a high-voltage
electronic control unit for the injection
system. Because of the high voltage it is
dangerous to touch any components of the
injection system (injectors, electrical wires)
R with the engine running
R while starting the engine
R when the ignition is switched on
XMake sure that the windshield wipers are
switched off.GWARNING
The windshield wipers and wiper linkage
could be set in motion.
When the hood is open, you or others could
be injured by the wiper linkage.
Make sure that the windshield wipers are
switched off. Remove the SmartKey or make
sure that no ignition position has been
selected with KEYLESS-GO. All indicator
lamps must be off in the instrument cluster.
282Engine compartmentMaintenance and care

Maintenance
Service interval display
Service messages
Information on the type of service and service
intervals (see separate Service Booklet).
You can obtain further information from an
authorized Mercedes-Benz Center or at
http://www.mbusa.com (USA only).
The service interval display informs you of the
next service due date.
If a service due date has been exceeded, you
also hear an acoustic signal.
The multifunction display shows a service
message for a few seconds, e.g.
Service A in .. mi
Service A due now
Service A overdue by .. mi
The letter indicates how much time the
workshop will require to carry out the service
work. The letters displayed range from A for
a short service duration to H for a long service
duration.
The service interval display does not take into
account any periods of time during which the
battery is disconnected.
Maintaining the time-dependent service
schedule:
XNote down the service due date displayed
in the multifunction display before
disconnecting the battery.
or
XSubtract the battery disconnection periods
from the service date shown on the display
after reconnecting the battery.
i The service interval display does not
provide any information regarding the
engine's oil level. Observe the notes on the
engine oil level ( Y page 283).
Hiding a service messageXPress the . reset button on the
instrument cluster ( Y page 29).
Displaying a service message
XSwitch on the ignition.XPress V or U to select the standard
display menu on the steering wheel
( Y page 202).XSelect & or * to select the service
interval display.
The service due date appears in the
multifunction display.
Please bear the following in mind
Resetting service interval display
If the qualified specialist workshop, e.g. a
Mercedes-Benz Center, carried out the
maintenance work, the service interval
display will be reset.
Further information, on maintenance for
example, can be obtained at an authorized
Mercedes-Benz Center or directly from
Mercedes-Benz.
! If the service interval display has been
reset unintentionally, have the setting
corrected at a Mercedes-Benz Center.
Have service work carried out as described
in the Service Booklet. This may otherwise
lead to increased wear and damage to the
major assemblies or the vehicle.
Driving abroad
An extensive Mercedes-Benz Service network
is also available in other countries. You can
obtain further information from any
authorized Mercedes-Benz Center.
Care
Notes on care
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Care287Maintenance 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