
Rthere are no, several or unclear lane mark-ings for a lane, e.g. in areas with road con-
struction work
Rthe lane markings are worn away, dark or
covered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
Rthe lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
Rthe road is narrow and winding
Rthere are strong shadows cast on the road
Activating/deactivating Lane Keeping
Assist
XTo activate: press button ;.
Indicator lamp :lights up. The Lane
Keeping Assist Onmessage appears in
the multifunction display. If all conditions
have been satisfied, there may be a warn-
ing.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected, the lines in the assistance graphics display
(
Ypage 251) are shown in green. Lane
Keeping Assist is ready for use.
XTo deactivate: press button;.
Indicator lamp :goes out. Lane Keeping
Assist is deactivated. The Lane Keeping
Assist Offmessage appears in the mul-
tifunction display. Selecting Standard or Adaptive setting
XIn the
DriveAssistmenu on the on-board
computer, select the Lane Keeping
Assistfunction (Ypage 253).
XSelectStandardorAdaptive.
Standard
When Standard
is selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, such as
ABS, BAS or ESP®.
Adaptive
When Adaptive
is selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
Ra driving safety system intervenes, e.g.
ABS, BAS or ESP®.
Ryou accelerate hard, e.g. kickdown.
Ryou brake hard.
Ryou steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
Ryou cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane
marking, the system recognizes certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a high-
way.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Driving system s221
Driving an d parking
Z

A lane-correcting brake application is inter-
rupted automatically if:
Ra driving safety system intervenes, e.g.
ESP®, PRE-SAFE®Brake or Active Blind
Spot Assist.
Rlane markings can no longer be recognized.
Activating/deactivating Active Lane
Keeping Assist
XTo activate: press button ;.
Indicator lamp :lights up. The Lane
Keeping Assist Onmessage appears in
the multifunction display. If all conditions
have been satisfied, a warning or steering
intervention may be made.
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected, the lines in the assistance graphics display
(
Ypage 251) are shown in green. Active
Lane Keeping Assist is ready for use.
XTo deactivate: press button;.
Indicator lamp :goes out. The Active
Lane Keeping Assist is deactivated. The
Lane Keeping Assist Off
message
appears in the multifunction display.
Selecting Standard or Adaptive setting
XIn the DriveAssistmenu on the on-board
computer, select the Active Lane Keep‐
ing Assistfunction (Ypage 253).
XSelectStandardorAdaptive.
When Standard
is selected, no warning
vibration occurs if:
Ryou switch on the turn signals. In this
event, the warnings are suppressed for a
certain period of time.
Ra driving safety system intervenes, such
as ABS, BAS or ESP®.
When Adaptive
is selected, no warning
vibration occurs if:
Ryou switch on the turn signals. In this
event, the warnings are suppressed for a
certain period of time.
Ra driving safety system intervenes, e.g.
ABS, BAS or ESP®.
Ryou accelerate hard, e.g. kickdown.
Ryou brake hard.
Ryou steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
Ryou cut the corner on a sharp bend.
In order that you are warned only when nec-
essary and in good time if you cross the lane
marking, the system recognizes certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
Ryou approach the outer lane marking on a
bend.
Rthe road has very wide lanes, e.g. a high-
way.
Rthe system recognizes solid lane markings.
The warning vibration occurs later if:
Rthe road has narrow lanes.
Ryou cut the corner on a bend.
Towing a trailer
Important safety notes
GWARNING
Installing an unsuitable ball coupling may
result in overloading of the trailer tow hitch
and the rear axle. This applies especially if the ball coupling in question is longer or angled
differently. This could seriously impair the
driving characteristics and the trailer can
come loose. There is a risk of an accident.
Towing a trailer227
Driving an d parking
Z

Safety systems
Display messagesPossible causes/consequences andMSolutions
!÷
Currently Unavail‐
able See Opera‐
tor's Manual
ABS (Anti-lock Brake System), ESP®(Electronic Stability Program),
BAS (Brake Assist), PRE‑ SAFE®, HOLD function, Crosswind Assist,
hill start assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are temporarily unavailable.
BAS PLUS with Cross-Traffic Assist, PRE‑SAFE
®Brake, PRE‑ SAFE®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
In addition, the ÷and! warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
For example, the on-board voltage may be insufficient.
GWARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XDrive on carefully.
Carefully drive a suitable distance, making slight steering move-
ments at a speed above 12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the multifunction display still shows the display message:
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
!÷
Inoperative See
Operator's Manual
ABS, ESP®, BAS, PRE‑SAFE®, HOLD function, Crosswind Assist,
hill start assist, STEER CONTROL, Active Lane Keeping Assist and Active Blind Spot Assist are unavailable due to a malfunction.
BAS PLUS with Cross-Traffic Assist, PRE‑ SAFE
®Brake, PRE‑SAFE®
PLUS and COLLISION PREVENTION ASSIST PLUS may also have
failed.
The$ (USA only) or J(Canada only), ÷and! warn-
ing lamps in the instrument cluster may also light up.
ATTENTION ASSIST is deactivated.
GWARNING
258Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
T!
÷
Inoperative See
Operator'sManual
EB D(electronic brak eforc edistribution), ABS, ES P®,BAS,
PRE ‑S AF E®,HOLD function ,Crosswin dAssist, hill start assist ,
STEE RCONTROL ,Active Lan eKeepin gAssis tand Active Blind
Spot Assis tare unavailable due to amalfunction .
BA SPLU Swit hCross-Traffic Assist, PRE‑ SAFE
®Brake,PRE ‑S AF E®
PLU Sand COLLISION PREVENTION ASSIST PLU Smay also hav e
failed.
In addition ,th e÷ and! warnin glamp sligh tup in th e
instrumen tcluster and awarnin gtone sounds.
GWARNIN G
The brakesystem continues to function normally, but without th e
function slisted above. The fron tand rear wheels could therefore
loc kif you brak ehard, fo rexample.
The steerabilit yand brakin gcharacteristics may be severely affec -
ted. The brakin gdistanc ein an emergenc ybrakin gsituation can
increase .
If ES P
®is no toperational, ES P®is unable to stabiliz eth evehicle.
There is an increase dris kof skiddin gand an accident.
XDrive on carefully.
XVisit aqualified specialist workshop immediately.
F(USA
only)
!(Canada
only)
Tur nOn the Igni‐
tio nto Releas e
the Parkin gBrake
The red F(USAonly) or !(Canada only) indicato rlamp
lights up.
You attempte dto release th eelectric parkin gbrak ewhile th eigni-
tion was switched off.
XSwitc hon th eignition .
F(USA
only)
!(Canada
only)
Please Releas e
ParkingBrake
The red F(USAonly) or !(Canada only) indicato rlamp
flashes and awarnin gtone sounds. Acondition fo rautomati c
release of th eelectric parkin gbrak eis no tfulfilled (
Ypage 174).
You are drivin gwit hth eelectric parkin gbrak eapplied.
XReleas eth eelectric parkin gbrak emanually.
The red F(USAonly) or !(Canada only) indicato rlamp
flashes and awarnin gtone sounds.
You are usin gth eelectric parkin gbrak efo remergenc ybrakin g
(
Ypage 174).
Display messages26 1
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
!NThe yellow ABS warning lamp is lit while the engine is running.
ABS (Anti-lock Braking System) is deactivated due to a malfunction. Therefore
BAS (Brake Assist), BAS PLUS with Cross-Traffic Assist, COLLISION PREVEN-
TION ASSIST PLUS, ESP
®(Electronic Stability Program), PRE‑SAFE®,
PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD function, Hill Start Assist,
Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and Active
Blind Spot Assist are also deactivated.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above. The wheels could therefore lock if you brake hard, for example.
The steerability and braking characteristics may be severely affected. The
braking distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
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.
294Warning and indicator lamps in the instrument cluster
On-board computer and displays

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
!NThe yellow ABS warning lamp is lit while the engine is running.
A warning tone also sounds.
EBD is not available due to a malfunction. Therefore ABS, BAS, BAS PLUS with
Cross-Traffic Assist, COLLISION PREVENTION ASSIST PLUS, ESP
®,
PRE‑SAFE®, PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD function, Hill Start
Assist, Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are also unavailable.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above. The front and rear wheels could therefore lock if you brake hard,
for example.
The steerability and braking characteristics may be severely affected. The
braking distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
Warning and indicator lamps in the instrument cluster295
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
$J
÷!N$ (USA only), J(Canada only): the red brake warning lamp and the
yellow ESP®and ABS warning lamps are lit while the engine is running.
ABS and ESP
®are not available due to a malfunction. Therefore BAS, BAS
PLUS with Cross-Traffic Assist, COLLISION PREVENTION ASSIST PLUS, EBD,
PRE‑SAFE
®, PRE‑SAFE®PLUS, PRE‑SAFE®Brake, the HOLD function, Hill Start
Assist, Crosswind Assist, STEER CONTROL, Active Lane Keeping Assist and
Active Blind Spot Assist are also unavailable.
ATTENTION ASSIST is deactivated.
GWARNING
The brake system continues to function normally, but without the functions
listed above. The front and rear wheels could therefore lock if you brake hard,
for example.
The steerability and braking characteristics may be severely affected. The
braking distance in an emergency braking situation can increase.
If ESP
®is not operational, ESP®is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
XObserve the additional display messages in the multifunction display.
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
÷N The yellow ESP®warning lamp flashes while the vehicle is in motion.
ESP
®or traction control has intervened because there is a risk of skidding or
at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
XWhen pulling away, only depress the accelerator pedal as far as necessary.
XEase off the accelerator pedal while the vehicle is in motion.
XAdapt your driving style to suit the road and weather conditions.
XDo not deactivate ESP®.
In rare cases (
Ypage 74), it may be best to deactivate ESP®.
Observe the important safety notes on ESP
®(Ypage 73).
296Warning and indicator lamps in the instrument cluster
On-board computer and displays

XHave the tire sealant bottle replaced as
soon as possible at a qualified specialist
workshop.
XHave the tire sealant bottle replaced every
four years at a qualified specialist work-
shop.
Battery (vehicle)
12 V battery – important safety notes
Special tools and expert knowledge are
required when working on the battery, e.g.
removal and installation. You should there-
fore have all work involving the battery car-
ried out at a qualified specialist workshop.
GWARNING
Work carried out incorrectly on the battery
can lead, for example, to a short circuit and
thus damage the vehicle electronics. This can
lead to function restrictions applying to
safety-relevant systems, e.g the lighting sys-
tem, the ABS (anti-lock braking system) or the
ESP
®(Electronic Stability Program). The oper-
ating safety of your vehicle may be restricted.
You could lose control of the vehicle, for
example:
Rwhen braking
Rin the event of abrupt steering maneuvers
and/or when the vehicle's speed is not
adapted to the road conditions
There is a risk of an accident.
In the event of a short circuit or a similar inci-
dent, contact a qualified specialist workshop
immediately. Do not drive any further. You
should have all work involving the battery car- ried out at a qualified specialist workshop.
For further information about ABS and ESP®,
see (
Ypage 67) and (Ypage 73).
All vehicles except vehicles with a lith-
ium-ion battery:
GWARNING
Electrostatic build-up can lead to the creation of sparks, which could ignite the highly explo-
sive gases of a battery. There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up.
The highly flammable gas mixture forms when
charging the battery as well as when jump-
starting.
Always make sure that neither you nor the
battery is electrostatically charged. A build-
up of electrostatic charge can be caused, for
example:
Rby wearing clothing made from synthetic
fibers
Rdue to friction between clothing and seats
Rif you push or pull the battery across the
carpet or other synthetic materials
Rif you wipe the battery with a cloth
GWARNING
During the charging process, a battery produ-
ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a
connected battery does not come into con- tact with vehicle parts.
RNever place metal objects or tools on a bat-
tery.
RIt is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
RWhen jump-starting, make sure that the
battery poles with identical polarity are
connected.
RIt is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
RNever connect or disconnect the battery
terminals while the engine is running.
Battery (vehicle)361
Breakdown assistance
Z