2012 MERCEDES-BENZ C-Class COUPE Owner's Manual

Display messagesPossible causes/consequences and M SolutionsCheck
TiresGRisk of accident
The tire pressure in one or more tires has dropped significantly.
The wheel position is displayed in the multifunction display.
A warning tone also sounds.
XStop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.XCorrect the tire pressure ( Y page 303).XIf necessary, change a wheel ( Y page 318).Caution:
Tire MalfunctionGRisk of accident
The tire pressure in one or more tires has dropped suddenly. The
wheel position is displayed in the multifunction display.
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 318).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 303).XRestart the tire pressure monitor ( Y page 305).Tire Press.
Sensor(s) MissingThere is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not displayed in the
multifunction display.XHave the defective tire pressure sensor replaced at a qualified
specialist workshop.Tire Press. Monitor
Currently Unavail.Due to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.XDrive on.
The tire pressure monitor restarts automatically as soon as the
problem has been solved.h
Tire Press.
Warning Caution
Tire MalfunctionGRisk of accident
The tire pressure in one or more tires has dropped suddenly.
A warning tone also sounds.
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 318).Display messages223On-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 318).XCheck the tire pressure. If necessary, correct the tire pressure
( Y page 303).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 303).
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.P
Shift to 'P'You have attempted to stop the engine with the Start/Stop button
while the transmission was not in position P.XShift the transmission to position P.While the HOLD function or DISTRONIC PLUS is active, you have:
R opened the driver's door and released the seat belt or
R switched off the engine or
R opened the hood
A tone may also sound at regular intervals. The tone becomes
louder if you attempt to lock the vehicle.
You cannot start the engine.XShift the transmission to position P.
You can restart the engine.NThe trunk lid is open.XClose the trunk lid.224Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsMGRisk of accident
The hood is open.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XApply the parking brake.XClose the hood.CAt least one door is open.XClose all the doors._
Lock Seat Backrest
Front Left or Lock
Seat Backrest
Front RightThe driver's or front passenger's seat backrest is not engaged. A
warning tone also sounds.XPush the backrest back until it engages.D
Power Steering
Malfunction See
Operator's ManualGRisk of accident
The power steering is malfunctioning.
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.Phone No ServiceYour vehicle is outside the network provider's transmitter/
receiver range.XWait until the mobile phone operational readiness symbol
appears in the multifunction display.¥
Check Washer FluidThe washer fluid level in the washer fluid reservoir has dropped
below the minimum.XAdd washer fluid ( Y page 267).Display messages225On-board computer and displaysZ

SmartKeyDisplay 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 72).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.Â
Key Not Detected
(red display message)The KEYLESS-GO key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle
centrally or start the engine.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XApply the parking brake.XLocate the KEYLESS-GO key.The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
A warning tone also sounds.XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.XEngage the parking brake.XOperate the vehicle with the SmartKey in the ignition lock.226Display messagesOn-board computer and displays

Display messagesPossible causes/consequences and M SolutionsÂ
Key Not Detected
(White display
message)The KEYLESS-GO key cannot be detected at present.XChange the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
XOperate the vehicle with the SmartKey in the ignition lock.Â
Key Detected in
VehicleThe KEYLESS-GO key has been detected inside the vehicle during
locking.XRemove the KEYLESS-GO key from the vehicle.Â
Remove 'Start'
Button and Insert
KeyKEYLESS-GO is temporarily malfunctioning or is defective. A
warning tone also sounds.XInsert the SmartKey into the ignition lock and turn it to the
desired position.XVisit a qualified specialist workshop.Â
Close Doors to
Lock VehicleAt least one door is open. A warning tone also sounds.XClose all doors and lock the vehicle again.
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 48).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 48).
The warning tone ceases.Warning and indicator lamps in the instrument cluster227On-board computer and displaysZ

ProblemPossible causes/consequences and M Solutions7
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 48).
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.7
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 48).
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.228Warning and indicator lamps in the instrument clusterOn-board computer and displays

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
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 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 cluster229On-board computer and displaysZ

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.
BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic Stability
Program), PRE-SAFE ®
Brake, the HOLD function and hill start
assist are therefore also deactivated, for example.
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. BAS, BAS PLUS, ESP ®
, EBD
(electronic brake force distribution), PRE-SAFE ®
Brake, the HOLD
function, hill start assist are therefore also deactivated, for
example.
Self diagnosis is not yet complete or the on-board voltage may be
insufficient, for example.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
ATTENTION ASSIST is deactivated.
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.230Warning and indicator lamps in the instrument clusterOn-board computer and displays