Problems with the engineProblemPossible causes/consequences and M SolutionsThe engine does not
start. The starter motor
can be heard.R There is a malfunction in the engine electronics.
R There is a malfunction in the fuel supply.XTurn the SmartKey back to position 0 in the ignition lock before
the next attempt to start with the SmartKey.XBefore the next starting attempt with KEYLESS-GO: shut all open
vehicle doors so that the signals from the SmartKey may be
better received.
or
XPull the Start/Stop button out of the ignition.XUse the SmartKey to start the engine, (Y page 301) as external
radio signals cause KEYLESS-GO to malfunction. Avoid
excessively long and frequent attempts to start the engine as
these will drain the battery.
If the engine does not start after several attempts:
XConsult a qualified specialist workshop.The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the starter battery is too
weak or discharged.XJump-start the vehicle ( Y page 471).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.The starter motor was exposed to a thermal load that was too high.XAllow the starter motor to cool down for approximately two
minutes.XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop.Driving305Driving and parkingZ
Problems with PARKTRONICProblemPossible causes/consequences and M SolutionsOnly the red segments
in the PARKTRONIC
warning displays are lit.
You also hear a warning
tone for approximately
two seconds.
PARKTRONIC is
deactivated after
approximately
20 seconds, and the
indicator lamp in the
PARKTRONIC button
lights up.PARKTRONIC has malfunctioned and has switched off.XIf problems persist, have PARKTRONIC checked at a qualified
specialist workshop.Only the red segments
in the PARKTRONIC
warning displays are lit.
PARKTRONIC is
deactivated after
approximately 20
seconds.The PARKTRONIC sensors are dirty or there is interference.XClean the PARKTRONIC sensors ( Y page 456).XSwitch the ignition back on.The problem may be caused by an external source of radio or
ultrasound waves.XSee if PARKTRONIC functions in a different location.Parking Guidance
Important safety notes
Parking Guidance is an electronic parking aid
with ultrasound. Ultrasound is used to
measure the road on both sides of the vehicle.
A suitable parking space is indicated by the
parking symbol. You receive steering
instructions when parking. You may also use
PARKTRONIC ( Y page 339).
GWarning
Parking Guidance is merely an aid and may
display parking spaces that are not suitable
for parking, for example:
R no-parking areas
R parking spaces with unsuitable surfaces
(road surface)
R driveways
R entrances and exits
Parking Guidance detects and measures
potential parking spaces while driving past.
Changes to the parking space after this point
are not taken into account, for example if the
vehicle in front of or behind the parking space
changes position or objects in the parking
space are moved.
Even when using Parking Guidance, you are
still responsible for driving carefully. If you
rely on Parking Guidance alone, you could
cause an accident and injure yourself and
others.
Safety always remains your responsibility and
you must continue paying careful attention to
your immediate surroundings when parking
and maneuvering.342Driving systemsDriving and parking
display = next to the symbol for the change
of direction ;. This decreases in size as you
approach the announced change of direction.
Change of direction announced with a
lane recommendation
Lane recommendations are only displayed if
the relevant data is available on the digital
map.
:Road into which the change of direction
leads
;Symbol for change of direction=Distance to change of direction and visual
distance display
?Lane recommendation
On multiple-lane roads, COMAND can provide
lane recommendation ? for the next change
of direction. Lanes may be added during a
change of direction.
:Uninterrupted lane;New lane during a change of direction=Lane recommended for the change of
direction
Other status indicators of the
navigation system
RO: you have reached the destination.
RNew Route...: COMAND is calculating the
new route.
RDirection of Dest. Off map or
Direction of Dest. Off mapped road:
the vehicle position is outside the area of
the digital map (off-map position).
RDirection of Dest. No Route: no route
could be calculated to the selected
destination.
Audio menu
Selecting a radio station
iSIRIUS XM satellite radio acts like a
normal radio.
For more information on satellite radio
operation, see the separate operating
instructions.
XSwitch on COMAND and select Radio
(Y page 208).
XPress the = or ; button on the
steering wheel to select the Audio menu.
:Memory slot (only if the channel is stored);Station=WavebandXTo select a stored channel: briefly press
the 9 or : button.
XTo select a channel from the channel
list: press and briefly hold the : or
9 button.
370Menus and submenusOn-board computer and displays
Display messagesPossible causes/consequences and M SolutionsG
Tele Aid
InoperativeUSA only: one or more main functions in the mbrace system are
malfunctioning.
Canada only: one or more of the main functions of the TELEAID
system is malfunctioning.XUSA only: have the mbrace system checked at a qualified
specialist workshop.XCanada only: have the TELEAID system checked at a qualified
specialist workshop.PRE-SAFE
Inoperative See
Oper. ManualGRisk of injury
Important functions of PRE-SAFE ®
have failed. All other occupant
safety systems, e.g. air bags, remain available.
XVisit a qualified specialist workshop immediately.PRE-SAFE
Functions
Currently Limited
See Operator's
ManualGRisk of accident
PRE-SAFE ®
Brake is temporarily inoperative if:
R the DISTRONIC PLUS cover in the radiator grill is dirty.
R the sensors in the bumpers are dirty.
R its function is impaired due to heavy rain or snow.
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 the system is outside the operating temperature range.
R the on-board voltage is insufficient.
PRE-SAFE ®
Brake is operational again and the display message
disappears when:
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 456).XClean the bumpers ( Y page 456).XRestart the engine.XWait until the battery is sufficiently charged.Display messages383On-board computer and displaysZ
Display messagesPossible causes/consequences and M SolutionsLane Keeping
Assist Currently
Unavailable See
Oper. Manual
Active Lane
Keeping Assist
Currently
Unavailable See
Oper. ManualLane Keeping Assist or Active Lane Keeping Assist is deactivated
and temporarily inoperative if:
R the windshield is dirty in the camera’s field of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for a longer period.
R the lane markings are worn, dark or covered, for example by dirt
or snow.
Lane Keeping Assist or Active Lane Keeping 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 camera is fully operational again.
If the display message continues to be displayed:XClean the windshield.Lane Keeping
Assist Inoperative
Active Lane
Keeping Assist
InoperativeLane Keeping Assist or Active Lane Keeping Assist is faulty.XVisit a qualified specialist workshop.Blind Spot Assist
Currently
Unavailable See
Oper. Manual
Active Blind Spot
Assist Currently
Unavailable See
Oper. 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 456).XRestart the engine.404Display messagesOn-board computer and displays
Display messagesPossible causes/consequences and M SolutionsDISTRONIC PLUS
Currently
Unavailable See
Oper. 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 456).XClean the bumpers ( Y page 456).XRestart the engine.DISTRONIC PLUS
InoperativeDISTRONIC PLUS is faulty. BAS PLUS and PRE-SAFE ®
Brake may
also have failed. 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 activation conditions for DISTRONIC PLUS
( Y page 325).406Display messagesOn-board computer and displays
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.
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 487).XIf necessary, change a wheel ( Y page 502).Caution
Tire DefectGRisk 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 502).Tire Pressure
Please RectifyThe tire pressure is insufficient 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 487).XRestart the tire pressure monitor ( Y page 489).Wheel 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 faulty tire pressure sensor replaced at a qualified
specialist workshop.Tire Pressure
Monitor
Currently
UnavailableNo signals are being received from the tire pressure sensors due
to radio interference. The tire pressure monitor is temporarily
malfunctioning.XDrive on.
The TPMS 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.
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 502).408Display messagesOn-board computer and displays
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 Key The 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 79).Â
Don't Forget Your
KeyThe display message is displayed for a maximum of 60 seconds
and is just a reminder.
You have opened the driver's door with the engine switched off.
The KEYLESS-GO key is not in the ignition lock.XTake the KEYLESS-GO key with you when leaving 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.XEngage 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 KEYLESS-GO key in the ignition
lock if necessary.Display messages411On-board computer and displaysZ