2012 MERCEDES-BENZ CL-Class check engine

ProblemPossible causes/consequences and M Solutions7
The red seat belt
warning lamp flashes
and an intermittent
audible warning
sounds.GRisk of injury
The driver or front passenger has not fastened their seat belt. In
addition, you are driving faster than 15 mph (25 km/h) or you have
briefly driven faster than 15 mph (25 km/h).
XFasten your seat belt ( Y page 51).
The warning lamp goes out and the intermittent warning tone
ceases.GRisk of injury
There are objects on the front-passenger seat. In addition, you are
driving faster than 15 mph (25 km/h) or you have briefly driven
faster than 15 mph (25 km/h).
XRemove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning tone
ceases.
Safety systems
ProblemPossible causes/consequences and M Solutions$ (USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds.GRisk of accident
There is not enough brake fluid in the brake fluid reservoir.
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 electric parking brake.XConsult a qualified specialist workshop immediately.XObserve the additional display messages in the multifunction
display.
Do not add brake fluid. This will not rectify the malfunction.
GWARNING
Driving with the brake warning lamp illuminated can result in an accident. Have your brake system
checked immediately if the brake warning lamp stays on. 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.
Warning and indicator lamps in the instrument cluster379On-board computer and displaysZ

ProblemPossible causes/consequences and M Solutionså
The yellow ESP ®
OFF
warning lamp is lit while
the engine is running.GRisk of accident
ESP ®
is deactivated. ESP ®
will not stabilize the vehicle if it starts
to skid or if a wheel starts to spin.
XReactivate ESP ®
.
Exceptions: ( Y page 64).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, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function and hill start assist 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.
The brake system continues to function normally, but without the
functions listed above.
ATTENTION ASSIST is deactivated.
XObserve the additional display messages in the multifunction
display.XDrive on carefully.XVisit a qualified specialist workshop.382Warning and indicator lamps in the instrument clusterOn-board computer and displays

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.
Engine
ProblemPossible causes/consequences and M Solutions;
The yellow Check
Engine warning lamp
lights up while the
engine is 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
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.
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the ;
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.384Warning and indicator lamps in the instrument clusterOn-board computer and displays

XPull release lever : for the hood.
The hood is released.
! Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood.
XReach into the gap, pull hood catch
handle ; up and lift the hood.
Once you have lifted the hood about
15 inches (40 cm), it is automatically
opened the rest of the way and held open
by the gas-filled struts.
Closing the hood
GWARNING
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure the hood is securely engaged
before driving off. Do not continue driving if
the hood can no longer engage after an
accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others.
XLower the hood and let it fall from a height
of approximately 8 inches (20 cm).XCheck that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force.Engine oil
Notes on the oil level
Depending on the driving style, the vehicle
consumes up to 0.9 US qts. (0.8 l) of oil over
a distance of 600 miles (1000 km). The oil
consumption may be higher than this when
the vehicle is new or if you frequently drive at
high engine speeds.
Checking the oil level using the oil
dipstick
On vehicles with a 12-cylinder engine, the oil
level can be checked using the on-board
computer. On all other models, the dipstick
must be used to check the engine oil level.
XPark the vehicle on a level surface.
To check the oil level with the engine at
operating temperature, switch the engine
off and wait for approximately five minutes.XPull oil dipstick : out of the dipstick guide
tube.XWipe off oil dipstick :.XSlowly slide oil dipstick : into the guide
tube to the stop, and take it out again.
If the level is between MIN mark = and
MAX mark ;, the oil level is correct.XIf the fuel level has sunk to MIN mark = or
below, add 0.55 to 1.1 US qt (0.5 to 1.0 l)
engine oil.Engine compartment409Maintenance and careZ

Checking the oil level using the on-
board computer
On vehicles with a 12-cylinder engine, the oil
level can be checked using the on-board
computer. On all other models, the dipstick
must be used to check the engine oil level.
XPark the vehicle on a level surface.
To check the oil level with the engine at
normal operating temperature, switch the
engine off and wait for approximately five
minutes.XMake sure that the SmartKey is in position
2 in the ignition lock.XPress the ; or = button to select the
Service menu.XPress the : or 9 button to select
Engine Oil Level .XPress the a button.
The multifunction display shows the
following message: Engine Oil Level
Measuring Now Measurement correct
only if vehicle level.
The measurement takes a few seconds. You
will see one of the following messages in the
multifunction display:
R Engine Oil Level OK
R Add 1.0 l Engine Oil At Next
Refueling
R Add 1.5 l Engine Oil At Next
Refueling
R Add 2.0 l Engine Oil At Next
Refueling
XAdd oil if necessary.
If the engine is at normal operating
temperature and the Engine Oil Level
Reduce Oil Level message appears, the
engine oil level is too high.
XHave excess oil siphoned off.
! Do not add too much oil. Adding too much
oil can result in damage to the engine or the
catalytic converter. Have excess oil
siphoned off.
If the For Engine Oil Level Ignition
Must be On message appears:XTurn the SmartKey to position 2 in the
ignition lock.
If the Need More Time to Check Engine
Oil Level message appears:
XIf the engine is at normal operating
temperature: repeat the measurement
after about five minutes.
If the engine is not at normal operating
temperature (e.g. if the engine was only
started briefly): repeat the measurement
after about 30 minutes.
If the Engine Oil Level Not When
Engine On message appears:
XSwitch off the engine.XIf the engine is at normal operating
temperature: wait about five minutes
before carrying out the measurement.
If the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly: wait about 30 minutes
before carrying out the measurement.
i If you wish to cancel the measurement,
press the % button on the multifunction
steering wheel.
Adding engine oil
GWARNING
If engine oil comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any engine oil on hot
engine parts.
HEnvironmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful
to the environment.
! Use only engine oils and oil filters that
have been approved for vehicles equipped
with a service system. A list of the engine
oils and oil filters tested and approved in
accordance with the Mercedes-Benz
410Engine compartmentMaintenance and care

Specifications for Service Products can be
called up by visiting http://
www.mbusa.com (USA only). More
information about tested and approved
engine oils and oil filters is available from
any authorized Mercedes-Benz Center.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters which
have not been specifically approved for
the service system.
R replacing the engine oil or oil filter after
the replacement interval required by the
service system has elapsed
R using engine oil additives.
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic
converter. Have excess oil siphoned off.
Example: engine oil cap
XTurn cap : counterclockwise and remove
it.XAdd engine oil.
Vehicles with oil level measurement
function in the on-board computer: observe
the information in the on-board computer
when doing so. Vehicles with oil dipstick: if
the oil level is at or below the MIN mark on
the oil dipstick,
add 0.55 to 1.1 US qt (0.5 to 1.0 l) engine
oil.XReplace cap : on the filler neck and turn
clockwise.
Ensure that the cap locks into place
securely.XCheck the oil level again with the oil
dipstick ( Y page 409) or the on-board
computer ( Y page 410).
Further information on engine oil
( Y page 478).
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 267) in the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button twice ( Y page 267).XCheck the coolant temperature display in
the instrument cluster.
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
Engine compartment411Maintenance and careZ

and windshield washer concentrate (e.g.
MB SummerFit).XAt temperatures below freezing: fill the
washer fluid reservoir with a mix of water
and windshield washer concentrate (e.g.
MB WinterFit). Adapt the mixing ratio to the
outside temperature. For information on
the mixing ratio ( Y page 480).XTo open: pull cap : upwards by the tab.XAdd the premixed washer fluid.XTo close: press cap : onto the filler neck
until it engages.
Brake fluid level
! If you notice that the brake fluid level in
the brake fluid reservoir has fallen to the
MIN mark or less, check the brake system
immediately for leaks. Also check the
thickness of the brake linings. Contact a
qualified specialist workshop, e.g. an
authorized Mercedes-Benz Center
immediately.
Do not add brake fluid. This does not
correct the error.
Only check the brake fluid level when the
vehicle is stationary and on a level surface.
The brake fluid level is correct if it is between
MIN marking ; and MAX marking : on the
brake fluid reservoir.
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.
Next service A due in .. days
Service A due
Service A overdue by .. days
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 409).
Maintenance413Maintenance and careZ

Wear eye protection.Keep children away.Observe this Operator's
Manual.HEnvironmental noteBatteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment.Dispose of batteries in an
environmentally friendly
manner. Return discharged
batteries to a qualified
specialist workshop, e.g. an
authorized Mercedes-Benz
Center, or to a special
collection point for old
batteries.GWARNING
Failure to follow these instructions can result
in severe injury or death.
Never lean over batteries while connecting.
You might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.
GWARNING
Do not place any metal objects on the battery
as this could result in a short circuit.
Use leak-proof batteries only to avoid the risk
of acid burns in the event of an accident.
Take care that you do not become statically
charged, e.g. by wearing synthetic clothing or
rubbing against textiles. For this reason, you
also should not pull or push the battery over
carpets or other synthetic materials.
Never touch the battery first. First, touch the
outside body of the vehicle in order to release
any possible electrostatic charges.
Do not rub the battery with rags or cloths. The
battery could explode if touched due to
electrostatic charge or due to spark
formation.
! Before working on the battery, e.g.
loosening the battery terminals, switch off
the engine and remove the SmartKey from
the ignition. On vehicles with KEYLESS-GO,
make sure that the ignition is switched off.
Check that all the indicator lamps in the
instrument cluster are off. You may
otherwise destroy electronic components,
such as the alternator.
! Like other batteries, the vehicle battery
may discharge over time if you do not use
the vehicle. In this case have the battery
checked at a qualified specialist workshop,
such as an authorized Mercedes-Benz
Center. You can also charge the battery
with a charger recommended by Mercedes-
Benz. Contact an authorized Mercedes-
Benz Center for more information.
The battery and the cover of the positive
terminal clamp must be installed securely
during operation.
i Remove the SmartKey if you park the
vehicle and do not require any electrical
consumers. The vehicle will then use very
little energy, thus conserving battery
power.
Battery431Breakdown assistanceZ