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Display messagesPossible causes/consequences and M Solutionsb
Check Front Left
Parking
Lamp orCheck Front
Right Parking LampThe front left or front right parking or standing lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Check Left Reverse
Lamp orCheck Right
Reverse LampThe left or right-hand backup lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Check Front Left
Sidemarker
Lamp orCheck Front
Right Sidemarker
LampThe left or right front side marker lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Check Rear Left
Sidemarker
Lamp orCheck Rear
Right Sidemarker
LampThe rear left or right side marker lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Check Left Daytime
Running
Light orCheck Right
Daytime Running
LightThe left or right-hand daytime running lamp is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Active Headlamps
InoperativeThe active light function is defective.XVisit a qualified specialist workshop.b
Malfunction See
Operator's ManualThe exterior lighting is defective.XVisit a qualified specialist workshop.224Display messagesOn-board computer and displays
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Display messagesPossible causes/consequences and M Solutionsb
AUTO Lamp Function
InoperativeThe light sensor is defective.XVisit a qualified specialist workshop.b
Switch Off LightsThe lights are still switched on when you leave the vehicle. A
warning tone also sounds.XTurn the light switch to c or à .Adaptive Highbeam
Assist InoperativeAdaptive Highbeam Assist is faulty.XVisit a qualified specialist workshop.Adaptive Highbeam
Assist Currently
Unavailable See
Operator's ManualAdaptive Highbeam Assist is deactivated and temporarily
inoperative. Possible causes are:
R the windshield in the camera's field of vision is dirty.
R visibility is impaired due to heavy rain, snow or fog.XClean the windshield.
If the system detects that the camera is fully functional again, the
Adaptive Highbeam Assist Now Available display message
is shown.
Adaptive Highbeam Assist is operational again.
Engine
Display messagesPossible causes/consequences and M Solutions+
Check Coolant
Level See
Operator's ManualThe coolant level is too low.XAdd coolant, observing the warning notes when doing so
( Y page 276).XIf coolant needs to be added 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
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Display messagesPossible causes/consequences and M SolutionsBlind Spot Assist
Currently
Unavailable See
Operator's
ManualBlind Spot
Assist Currently
Unavailable See
Operator's Manual
or Active Blind
Spot Assist
Currently
Unavailable See
Operator's ManualBlind Spot Assist or Active Blind Spot Assist is temporarily
inoperative if:
R the sensors are dirty.
R its function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
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.
The yellow 9 indicator lamps also light up in the exterior
mirrors.
Blind Spot Assist or Active Blind Spot Assist 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 radar sensor system is back within the operating
temperature range.
If the display message continues to be displayed:XClean the sensors ( Y page 284).XRestart the engine.Blind Spot Assist
Inoperative or
Active Blind Spot
Assist InoperativeBlind Spot Assist or Active Blind Spot Assist is defective.
The yellow 9 indicator lamps also light up in the exterior
mirrors.XVisit a qualified specialist workshop.Parking Guidance
InoperativeParking Guidance is malfunctioning ( Y page 181).XRestart the engine.
If the display message continues to be displayed:
XVisit a qualified specialist workshop.230Display messagesOn-board computer and displays
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Display messagesPossible causes/consequences and M Solutions+
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.+
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 belt
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 50).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 50).
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 50).
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.240Warning and indicator lamps in the instrument clusterOn-board computer and displays
Page 247 of 352

EngineProblemPossible 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.
8
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.8
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.Warning and indicator lamps in the instrument cluster245On-board computer and displaysZ
Page 248 of 352
ProblemPossible causes/consequences and M Solutions?
The red coolant
warning lamp lights up
while the engine is
running and the coolant
temperature gauge is
at the start of the scale.The temperature sensor for the coolant temperature gauge is
defective.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.XPull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions. Do not continue
driving under any circumstances.XApply the parking brake.XConsult a qualified specialist workshop.246Warning and indicator lamps in the instrument clusterOn-board computer and displays
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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.
! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged.
Driving systems
ProblemPossible 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 PLUS ( Y page 166) and
PRE-SAFE ®
Brake ( Y page 65).
248Warning and indicator lamps in the instrument clusterOn-board computer and displays
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XTo open: pull handle : and open glove box
flap ;.XTo close: fold glove box flap ; upwards
until it engages.
The glove box can only be locked and
unlocked using the mechanical key.
XTo lock: insert the mechanical key into the
lock and turn it 90° clockwise to position
2 .XTo unlock: insert the mechanical key into
the lock and turn it 90° counter-clockwise
to position 1.
Stowage compartment under the armrest
i A small and a large stowage compartment
are located under the armrest. The small
stowage compartment can be removed for
emptying.
i Depending on the vehicle's equipment, a
USB connection and an AUX IN connection
or a Media Interface are installed in the
stowage compartment. A Media Interface
is a universal interface for mobile audio
equipment, e.g. for an iPod ®
or MP3 player
(see the separate COMAND operating
instructions).XTo open: press left-hand button ; or right-
hand button :.
The stowage compartment opens.
Parcel nets
GWARNING
Parcel nets are intended for storing light-
weight items only, such as road maps, mail,
etc.
Heavy objects, objects with sharp edges, or
fragile objects may not be transported in the
parcel nets. In an accident, during hard
braking, or sudden maneuvers, they could be
thrown around inside the vehicle and cause
injury to vehicle occupants.
Parcel nets cannot protect transported goods
in the event of an accident.
Parcel nets are located in the front-passenger
footwell and on the left-hand side of the trunk
(Coupe) or left and right-hand sides of the
trunk (Cabriolet).
Through-loading facility in the rear
compartment
GWARNING
Do not transport any unsecured items in the
through-loading area.
Stowage areas253Stowing and featuresZ