Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
In some states, you must immediately visit a qualified specialist workshop as soon as the yellow Check Engine warning lamp lights up. This is due to the legal require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
Vehicles with a diesel engine: the fuel tank has been run dry (
Ypage 151).
XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency running mode is
canceled. The vehicle need not be checked.
8N 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.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
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.
?NThe 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 malfunctioning.
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.
XSecure the vehicle against rolling away (Ypage 154).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster263
On-board computer and displays
Z
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 154).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 309).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature is below 248 ‡
(120 †). Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running. A warning
tone also sounds.
The coolant temperature has exceeded 248 ‡(120 †). The airflow to the engine
radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some fluids which
may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 154).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 309).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
264Warning and indicator lamps in the instrument cluster
On-board computer and displays
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
XAt coolant temperatures below 248 ‡ (120 †), drive to the nearest qualified
specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
Driving systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
·NThe red distance warning lamp lights up while the vehicle is in motion. A warning
tone also sounds.
You are approaching a vehicle, a pedestrian or a stationary obstacle in your line of travel 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.
Further information on PRE ‑SAFE
®Brake (Ypage 73).
For further information about the distance warning function of COLLISION PRE-
VENTION ASSIST PLUS, see (
Ypage 67).
Warning and indicator lamps in the instrument cluster265
On-board computer and displays
Z
Tires
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
hNThe yellow tire pressure monitor warning lamp (pressure loss/malfunction) is lit.
The tire pressure monitor has detected a loss of pressure in at least one of the tires.
GWARNING
Tire pressures that are too low pose the following hazards:
Rthey may burst, especially as the load and vehicle speed increase.
Rthey may wear excessively and/or unevenly, which may greatly impair tire trac-
tion.
Rthe driving characteristics, as well as steering and braking, may be greatly
impaired.
There is a risk of an accident.
XStop the vehicle without making any sudden steering or braking maneuvers. Pay
attention to the traffic conditions as you do so.
XSecure the vehicle against rolling away (Ypage 154).
XObserve the additional display messages in the multifunction display.
XCheck the tires and, if necessary, follow the instructions for a flat tire
(Ypage 321).
XCheck the tire pressure (Ypage 345).
XIf necessary, correct the tire pressure.
hN The yellow tire pressure monitor warning lamp (pressure loss/malfunction)
flashes for approximately one minute and then remains lit.
The tire pressure monitor is faulty.
GWARNING
The system is possibly unable to recognize or register low tire pressure.
There is a risk of an accident.
XObserve the additional display messages in the multifunction display.
XVisit a qualified specialist workshop immediately.
266Warning and indicator lamps in the instrument cluster
On-board computer and displays
Vehicle
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
ÐNThe red power steering warning lamp is lit while the engine is running.
The power steering is malfunctioning.
A warning tone also sounds.
GWARNING
You will need to use more force to steer.
There is a risk of an accident.
XCheck whether you are able to apply the extra force required.
If you are able to steer safely:
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
If you are unable to steer safely:
XDo not drive on.
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster267
On-board computer and displays
Z
General notes
The multimedia system section in this Opera-
tor's Manual describes the basic principles for
operation. More information can be found in theDigital Operator's Manual.
Important safety notes
GWARNING
If you operate information systems and com-
munication equipment integrated in the vehi-
cle while driving, you will be distracted from
traffic conditions. You could also lose control
of the vehicle. There is a risk of an accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for the
country in which you are currently driving when
operating the multimedia system.
The multimedia system calculates the route to
the destination without taking the following into
account, for example:
Rtraffic lights
Rstop and yield signs
Rparking or stopping restrictions
Rroad narrowing
Rother road and traffic rules and regulations
The multimedia system may give incorrect nav-
igation recommendations if the actual street/
traffic situation does not correspond with the
digital map's data.
For example:
Ra diverted route
Rthe road layout or the direction of a one-way
street has been changed
For this reason, you must always observe road
and traffic rules and regulations during your
journey. Road and traffic rules and regulations
always have priority over multimedia system
driving recommendations.
Navigation announcements are intended to
direct you while driving without diverting your
attention from the road and driving. Please always use this feature instead of con-
sulting the map display for directions. Looking
at the icons or map display can distract you from
traffic conditions and driving, and increase the
risk of an accident.
This equipment complies with FCC radiation
exposure limits set forth for uncontrolled equip-
ment and meets the FCC radio frequency (RF)
Exposure Guidelines in Supplement C to OET65.
This equipment has very low levels of RF energy
that is deemed to comply without maximum
permissive exposure evaluation (MPE). How-
ever, it is recommended
to insta
ll it at a distance
of at least 8 inches (approx. 20 cm) between the
radiation source and a person's body (not
including limbs such as hands, wrists, feet and
legs).
GWARNING
Modifications to electronic components, their software as well as wiring can impair their
function and/or the function of other net-
worked components. In particular, systems
relevant to safety could also be affected. As a
result, these may no longer function as inten-
ded and/or jeopardize the operating safety of
the vehicle. There is an increased risk of an
accident and injury.
Never tamper with the wiring as well as elec-
tronic components or their software. You
should have all work to electrical and elec-
tronic equipment carried out at a qualified
specialist workshop.
Function restrictions
For safety reasons, some functions are restric-
ted or unavailable while the vehicle is in motion.
You will notice this, for example, because either
you will not be able to select certain menu items
or a message will appear to this effect.
268Function restrictions
Multimedia system
XTo set the intensity: turn the controller when
the atomizer is switched on.
XTo exit the menu:press the%button.
Switching the ionization on/off
The ionization has a cleansing effect on the air in
the vehicle interior. Further information
(
Ypage 129).
XCall up the climate control menu
(Ypage 272).
XTo select Ionization: turn and press the
controller.
The setting element is active.
XTo switch the ionization on or off: turn the
controller.
XTo exit the menu: press the%button.
Settings in the bottom bar of the cli-
mate control menu
Switching cooling with air dehumidifica-
tion on/off
XCall up the climate control menu
(Ypage 272).
XSlide6the controller repeatedly until the
bottom bar is activated.
XTo select OA/C: turn and press the control-
ler.
XSwitch cooling with air dehumidification on
O or off ª.
iThe current status of the cooling function is
displayed in the climate control bar: A/C ON
– activated, A/C OFF – deactivated.
iDeactivating the cooling with air dehumidi-
fication function reduces fuel consumption.
Synchronizing the climate control set-
tings
Use OSync(synchronization) to select the cli-
mate control setting for all zones together Oor
separately ª.
XCall up the climate control menu
(Ypage 272).
XSlide6the controller repeatedly until the
bottom bar is activated.
XTo select OSync: turn and press the con-
troller.
XSwitch the synchronization function on Oor
off ª. For further information on synchronizing climate
control settings, see (
Ypage 126).
Navigation mode
Important safety notes
GWARNING
If you operate information systems and com-
munication equipment integrated in the vehi-
cle while driving, you will be distracted from
traffic conditions. You could also lose control
of the vehicle. There is a risk of an accident.
Only operate the equipment when the traffic
situation permits. If you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the equip-
ment when the vehicle is stationary.
You must observe the legal requirements for the
country in which you are currently driving when
operating the navigation system.
General notes
Among other things, correct functioning of the
navigation system depends on GPS reception. In
certain situations, GPS reception may be
impaired, there may be interference or there
may be no reception at all, e.g. in tunnels or
parking garages.
Audio 20 is equipped with Garmin
®MAP PILOT
(see the manufacturer's operating instructions).
The Garmin
®MAP PILOT operating instructions
are stored on the SD card as a PDF file. The SD
card box contains a quick guide.
The following descriptions apply to navigation
with COMAND. Further information can be
found in the Digital Operator's Manual.
Selecting a route type and route options
Multimedia system:
XSelect NaviQNavigation.
XSelectOptionsQRoute Settings.
iIf route guidance is active, first slide 6the
controller and show the menu.
XSelect a route type.
Operating system273
Multimedia system
Z
minutes to be displayed (see the manufactur-
er's operating instructions).
XIf the codes are different:selectNoon the
multimedia system.
The process is canceled.
Repeat authorization.
Authorization by entering a passkey (passcode):
XSelect Bluetooth®name of the mobile phone.
The input menu for the passkey is displayed.
XChoose a one to sixteen-digit number combi- nation as a passkey.
XEnter the passkey on the multimedia system.
XPress ¬to confirm.
XEnter and confirm the passkey on the mobile
phone. Depending on the mobile phone used,
confirm the connection to the multimedia sys-
tem and for the PBAP and MAP Bluetooth
®
profiles. The prompt to confirm may take up
to two minutes to be displayed (see the man-
ufacturer's operating instructions).
Switching between mobile phones
If you have authorized more than one mobile
phone, you can switch between the individual
phones.
Multimedia system:
XSelect Connect Device.
XSelect a mobile phone from the device list.
Media mode
General notes
If you wish to play external media sources, the
default display must already be turned on. Fur-
ther information on media mode (see the Digital
Operator's Manual).
The following external media sources can be
used:
RApple®devices (e.g. iPhone®)
RUSB devices (e.g. USB stick, MP3 player)
RCD
RDVD (COMAND)
RSD cards
Rvia devices connected by Bluetooth®
Activating media mode
Multimedia system:
XSelect MediaQDevices.
The available media sources will be shown.
XSelect the media source.
Playable files are played.
Inserting and removing an SD card
Important safety notes
GWARNING
SD cards are small parts. They can be swal-
lowed and cause choking. This poses an
increased risk of injury or even fatal injury.
Keep the SD card out of the reach of children. If a SD card is swallowed, seek medical atten-
tion immediately.
!If you are no longer using the SD card, you
should remove it and store it outside the vehi-
cle. High temperatures can damage the card.
Inserting an SD card
The SD card slot is located in the stowage com-
partment under the armrest.
XInsert the SD card into the SD card slot until
the SD card engages. The side with the con-
tacts must face down.
XSelect the media source (Ypage 276).
Removing an SD card
XPress the SD card.
The SD card is ejected.
XRemove the memory card.
Connecting USB devices
276Operating system
Multimedia system