
GWARNING
If the 45 indicator lamp remains lit with an adult occupant on the front-passenger seat
even after performing the above corrective steps, do not have any passenger use the front-
passenger seat until the system has been repaired.
Lights
i Display messages about LEDs:
This display message will only appear if all LEDs have failed.
Display messagesPossible causes/consequences and M Solutionsb
Check Left
Cornering
Light orCheck Right
Cornering LightThe left or right-hand cornering light is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Check Left Low
Beam orCheck Right
Low BeamThe left or right-hand low-beam headlamp 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
Turn Signal orCheck
Rear Right Turn
SignalThe rear left-hand or rear right-hand turn signal 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
Turn Signal orCheck
Front Right Turn
SignalThe front left-hand or front right-hand turn signal is defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.b
Check Left Mirror
Turn Signal orCheck
Right Mirror Turn
SignalThe turn signal in the left-hand or right-hand exterior mirror is
defective.XCheck whether you are permitted to change the bulb yourself
( Y page 122).
or
XVisit a qualified specialist workshop.222Display messagesOn-board computer and displays

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

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

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

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

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

of the garage door drive. You might require
several attempts. You should test every
position for at least 25 seconds before
trying another position.XPress and hold transmitter button B on
garage door remote control A until
indicator lamp : lights up green.
Programming is complete if indicator
lamp : lights up or flashes green.XRelease transmitter button ;, = or ? on
the integrated garage door opener and the
transmitter button on garage door remote
control B.
If indicator lamp : lights up red:
XRepeat the programming procedure for the
transmitter button. When doing so, vary the
distance between the garage door remote
control and the rear-view mirror.
i If the indicator lamp flashes green after
successful programming, the garage door
system is operating on a rolling code. After
programming, you must synchronize the
garage door opener integrated in the rear-
view mirror with the receiver of the garage
door system.
Synchronizing the rolling code
Your vehicle must be within range of the
garage or gate opener drive. Make sure that
neither your vehicle nor any persons/objects
are present within the sweep of the door or
gate.
Observe the safety notes when performing
the rolling code synchronization.
XTurn the SmartKey to position 2 in the
ignition lock.XPress the programming button of the door
or gate drive (see the door or gate drive
operating instructions, e.g. under
"Programming of additional remote
controls").i You now normally have 30 seconds to
initiate the next step.XPress the previously programmed
transmitter button of the HomeLink ®
integrated garage door opener repeatedly
in succession until the door opens.
The rolling code synchronization is then
complete.
Notes on programming the remote
control
Canadian radio frequency laws require a
"break" (or interruption) of the transmission
signals after broadcasting for a few seconds.
These signals may not therefore last long
enough for the integrated garage door opener
to recognize the signal during programming.
Comparable with Canadian law, some U.S.
garage door openers also have a built-in
"interruption".
If you live in Canada or have difficulties
programming the garage door opener
(regardless of where you live) when using the
programming steps (see above), proceed as
follows:
XPress and hold one of transmitter
buttons ; to ? of the integrated garage
door opener.
Indicator lamp : starts to flash yellow
after a short period.XRelease the transmitter button.XPress transmitter button B of the garage
door remote control and hold for two
seconds, then release for two seconds,
then press again and hold for two seconds.XRepeat this sequence on transmitter
button B of the garage door remote
control until indicator lamp : is green.
Repeat the process if indicator lamp :
turns red.XContinue with the other programming
steps (see above).Features269Stowing and featuresZ

Problems when programming
If you are experiencing problems
programming the integrated garage door
opener on the rear-view mirror, take note of
the following instructions:
R check the transmission frequency of
garage door remote control A (usually
found on the reverse side of the remote
control).
The integrated garage door opener is
compatible with devices that can be
operated with units in a frequency range of
280 to 390 MHz.
R change the batteries in garage door remote
control A. This increases the probability
that garage door remote control A will
send a strong and precise signal to the
integrated garage door opener on the rear-
view mirror.
R when programming, hold garage door
remote control A at different distances
and angles from the transmitter button that
you are programming. Try different angles
at a distance between 2 and 12 inches (5
to 30 cm) or the same angle at varying
distances.
R if another remote control for the same
garage door drive is available, repeat the
same programming steps with this remote
control. Before you perform the steps of the
operation, make sure that there are new
batteries in the garage door remote
control.
R note that some remote controls only
transmit for a limited amount of time (the
indicator lamp on the remote control goes
out). Press the remote control button again
before it stops transmitting.
R align the antenna cable of the garage door
opener unit. This can improve signal
reception/transmission.Opening/closing the garage door
Once programmed, the integrated garage
door opener will assume the function of the
garage door system's remote control. Please
also read the operating instructions for the
garage door system.
XTurn the SmartKey to position 2 in the
ignition lock.XPress transmitter button ;, = or ? in the
overhead control panel that you have
programmed to operate the garage door.
Garage door system with a fixed code:
indicator lamp : lights up green.
Garage door system with a rolling code:
indicator lamp : flashes green.
i
The transmitter will transmit a signal for
as long as the transmitter button is being
pressed. After a maximum of ten seconds,
transmission is terminated and indicator
lamp : flashes yellow. Press the
transmitter button again, if necessary.
Clearing the memory of the integrated
garage door opener on the rear-view
mirror
XTurn the SmartKey to position 2 in the
ignition lock.XPress transmitter buttons ; and ?.
The indicator lamp lights up yellow.XPress and hold transmitter buttons ;
and ? until the indicator lamp turns green.
i
Make sure that you clear the memory of
the integrated garage door opener before
selling the vehicle.
270FeaturesStowing and features