2012 MERCEDES-BENZ CLS-Class check engine

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 messagesPossible causes/consequences and M Solutions?
Coolant Level Low
Stop Vehicle Turn
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.
Display messages227On-board computer and displaysZ

! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.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.4
Check Engine Oil
At Next RefuelingThe engine oil level has dropped to a critical level.
A warning tone also sounds.XCheck the oil level ( Y page 281).XIf necessary, add engine oil ( Y page 282).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.
228Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsDISTRONIC PLUS
Currently
Unavailable See
Operator's ManualDISTRONIC PLUS is deactivated and is temporarily inoperative if:
R the DISTRONIC PLUS cover in the radiator grill is dirty.
R the sensors in the bumpers are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
R its function is impaired due to heavy rain or snow.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
A warning tone also sounds.
DISTRONIC PLUS is operational again and the display message
disappears if:
R the dirt (e.g. slush) drops away while the vehicle is in motion.
R the system detects that the sensors are fully available again.
R the system is within the operating temperature range.
If the display message continues to be displayed:XClean the DISTRONIC PLUS cover in the radiator grill
( Y page 289).XClean the bumpers ( Y page 289).XRestart the engine.DISTRONIC PLUS
InoperativeDISTRONIC PLUS is defective. BAS PLUS (Brake Assist PLUS) and
PRE-SAFE ®
Brake may be inoperative as well.
A warning tone also sounds.XVisit a qualified specialist workshop.DISTRONIC PLUS
OverrideYou have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.XTake your foot off the accelerator pedal.DISTRONIC PLUS
--- mphAn activation condition for DISTRONIC PLUS is not fulfilled.XCheck the activation conditions for DISTRONIC PLUS
( Y page 157).Display messages233On-board computer and displaysZ

Display messagesPossible causes/consequences and M Solutionsh
Check Tire PressureGRisk of accident
The tire pressure in one or more tires has dropped significantly.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XIf necessary, change a wheel ( Y page 338).XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 322).h
Correct Tire
PressureThe tire pressure is too low in at least one of the tires or the tire
pressure difference between the wheels is too great.XCheck the tire pressures at the next opportunity. If necessary,
correct the tire pressure ( Y page 322).
Vehicle
Display messagesPossible causes/consequences and M SolutionsShift to 'P' or 'N'
to Start EngineYou have attempted to start the engine with the transmission in
position R or D.XShift the transmission to position P or N.Auxiliary Battery
MalfunctionThe auxiliary battery for the automatic transmission is no longer
being charged.XVisit a qualified specialist workshop.Apply Brake to
Shift from 'P' You have attempted to move the transmission selector lever to
position D, R or N without depressing the brake pedal.XDepress the brake pedal.Door Open
Vehicle Not in 'P'The driver's door is open and the transmission is in position R, N
or D.
A warning tone also sounds.XShift the transmission to position P.XEngage the parking brake.Display messages237On-board computer and displaysZ

Display messagesPossible causes/consequences and M SolutionsD
Power Steering
Malfunction See
Operator's ManualGRisk of accident
The power steering assistance is defective.
You will need to use more force to steer.
A warning tone also sounds.
XCheck whether you are able to apply the extra force required.XIf you are able to steer safely: carefully drive on to a qualified
specialist workshop.XIf you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop.¥
Check Washer FluidThe washer fluid level in the washer fluid reservoir has dropped
below the minimum.XAdd washer fluid ( Y page 283).
SmartKey
Display messagesPossible causes/consequences and M SolutionsÂ
Key Does Not
Belong to VehicleYou have put the wrong SmartKey in the ignition lock.XUse the correct SmartKey.Â
Take Your Key from
IgnitionThe SmartKey is in the ignition lock.XRemove the SmartKey.Â
Obtain a New KeyThe SmartKey needs to be replaced.XVisit a qualified specialist workshop.Â
Replace Key BatteryThe batteries of the KEYLESS-GO key are discharged.XChange the batteries ( Y page 76).Â
Don't Forget Your
KeyThe display message is shown for a maximum of 60 seconds and
is only a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.XRemember to take the KEYLESS-GO key with you when you
leave the vehicle.Display messages239On-board computer and displaysZ

Safety systemsProblemPossible 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
The brake boosting effect is malfunctioning and the braking
characteristics may be affected.
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.XObserve the additional display messages in the multifunction
display.$ (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 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 correct 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 cluster243On-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 ®
.
For exceptions: ( Y page 63).XAdapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
XHave ESP ®
checked at a qualified specialist workshop.M
AMG vehicles only:
The yellow SPORT
handling mode warning
lamp is lit while the
engine is running.GRisk of accident
SPORT handling mode is activated. ESP ®
only stabilizes the vehicle
in extreme situations. ESP ®
intervention may not be able to
provide sufficient assistance in such situations and the vehicle
may start to skid.
XReactivate ESP ®
.
Exceptions: ( Y page 63).
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.246Warning 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.6
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 cluster247On-board computer and displaysZ