Checking the battery
X
Press the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
If battery check lamp :does not light up
briefly during the test, the battery is
discharged.
i If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the &or% button:
R locks or
R unlocks the vehicle
X Change the battery (Y page 79).
i You can get a battery at a qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X Take the mechanical key out of the
SmartKey (Y page 78). X
Press mechanical key ;into the SmartKey
opening in the direction of the arrow until
battery compartment cover :opens. Do
not hold battery compartment cover :
closed while doing so.
X Remove battery compartment cover :. X
Repeatedly tap the SmartKey against your
palm until battery =falls out.
X Insert the new battery with the positive
terminal facing upwards. Use a lint-free
cloth to do so.
X Make sure that the surface of the battery is
free from lint, grease and all other forms of
contamination.
X Insert the front tabs of battery
compartment cover :into the housing
first and then press to close it.
X Insert mechanical key ;into the
SmartKey.
X Check the function of all SmartKey buttons
on the vehicle. SmartKey
79Opening and closing Z
HOLD function is still activated. If you attempt
to lock the vehicle, the tone becomes louder.
The vehicle is not locked until the HOLD
function is deactivated.
i If the engine has been switched off, it
cannot be started again until the HOLD
function has been deactivated.
If there is a malfunction in the system or
power supply while the HOLD function is
activated, the Brake BrakeImmediately
Immediately message
is shown in the multifunction display.
Immediately depress the brake firmly until
the warning message in the multifunction
display goes out.
You can also shift the transmission to position
P. This deactivates the HOLD function. PARKTRONIC
Important safety notes PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It monitors the area
around your vehicle using six sensors in the
front bumper and four sensors in the rear
bumper. PARKTRONIC indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is only an aid. It is not a
replacement for your attention to your
immediate surroundings. You are always
responsible for safe maneuvering, parking
and exiting a parking space. When
maneuvering, parking or pulling out of a
parking space, make sure that there are no
persons, animals or objects in the area in
which you are maneuvering.
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars.
PARKTRONIC does not detect such objects
when they are in the immediate vicinity of
the vehicle. You could damage the vehicle
or the objects.
The sensors may not detect snow and other
objects that absorb ultrasonic waves. Ultrasonic sources such as an automatic
car wash, the compressed-air brakes on a
truck or a pneumatic drill could cause
PARKTRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is activated automatically when
you:
R switch on the ignition
R shift the transmission to position D,Ror N
R release the parking brake
PARKTRONIC is deactivated at speeds above
11 mph (18 km/h). It is reactivated at lower
speeds. :
Sensors in the front bumper, left-hand
side (example)
Range of the sensors General notes
PARKTRONIC does not take objects into
consideration that are:
R
below the detection range, e.g. people,
animals or objects
R above the detection range, e.g.
overhanging loads, truck overhangs or
loading ramps
The sensors must be free from dirt, ice or
slush. They can otherwise not function
correctly. Clean the sensors regularly, taking
care not to scratch or damage them
(Y page 309). Driving systems
185Driving and parking Z
Important safety notes
If you fail to adapt your driving style, Lane
Keeping Assist can neither reduce the risk of
an accident nor override the laws of physics.
Lane Keeping Assist cannot take into account
the road, traffic and weather conditions. Lane
Keeping Assist is merely an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time and for staying in your lane. G
WARNING
Lane Keeping Assist may not always clearly
recognize lane markings.
In this case, Lane Keeping Assist may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and stay in lane, in particular if
warned by Lane Keeping Assist. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There
is a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane
Keeping Assist.
The Lane Keeping Assist does not keep the
vehicle in the lane.
The system may be impaired or may not
function if:
R there is poor visibility, e.g. due to
insufficient illumination of the road, or due
to snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflections (e.g. when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera R
there are no, several or unclear lane
markings for a lane, e.g. in areas with road
construction work
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are strong shadows cast on the lane
Switching on Lane Keeping Assist
X Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard
Standard orAdaptive Adaptive (Ypage 229).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
(Y page 228) are shown in green. Lane
Keeping Assist is ready for use.
Standard
If Standard Standard is selected, no warning vibration
occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
Adaptive
When Adaptive Adaptive is selected, no warning
vibration occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard. Driving systems
205Driving and parking Z
This function is available in the range between
40 mph and 120 mph (60 km/h and
200 km/h).
A lane-correcting brake application can only
be made after driving over a solid,
recognizable lane marking. Before this, a
warning must be given by means of
intermittent vibration in the steering wheel.
In addition, a lane with lane markings on both
sides must be recognized. The brake
application also slightly reduces vehicle
speed.
If a lane-correcting brake application occurs,
the following, for example, appears in the
multifunction display: i
A further lane-correcting brake
application can only occur after your
vehicle has returned to the original lane.
No lane-correcting brake application occurs
if:
R you clearly and actively steer, brake or
accelerate.
R you cut the corner on a sharp bend.
R you switch on the turn signals.
R a driving safety system intervenes, e.g.
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist.
R you have adopted a sporty driving style with
high cornering speeds or high rates of
acceleration.
R on vehicles with a trailer tow hitch, the
electrical connection to the trailer has been
correctly established.
R ESP ®
is switched off. R
the transmission is not in position D.
R the off-road program is activated.
R a loss of tire pressure or a defective tire has
been detected and displayed.
Active Lane Keeping Assist does not detect
traffic situations or road users. An
inappropriate brake application may be
interrupted at any time if you:
R steer slightly in the opposite direction
R use a turn signal
R clearly brake or accelerate
A lane-correcting brake application is
interrupted automatically if:
R a driving safety system intervenes, e.g.
ESP ®
, PRE-SAFE ®
Brake or Active Blind
Spot Assist.
R lane markings can no longer be recognized.
Switching on Active Lane Keeping Assist
X Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard Standard orAdaptive
Adaptive (Ypage 229).
If you drive at speeds above 40 mph
(60 km/h) and lane markings are detected,
the lines in the assistance graphics display
(Y page 228) are shown in green. Lane
Keeping Assist is ready for use.
If Standard Standard is selected, no warning
vibration occurs if:
R you have switched on the turn signals. In
this event, the warnings are suppressed
for a certain period of time.
R a driving safety system intervenes, such
as ABS, BAS or ESP ®
.
When Adaptive Adaptive is selected, no warning
vibration occurs if:
R you have switched on the turn signals. In
this event, the warnings are suppressed
for a certain period of time.
R a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard. Driving systems
211Driving and parking Z
Safety systems
Display messages Possible causes/consequences and
M
MSolutions !÷
Currently Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability
Program), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function, hill
start assist and ESP ®
trailer stabilization are temporarily
unavailable.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷,åand! warning lamps light up in
the instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes are:
R self-diagnosis is not yet complete.
R the on-board voltage may be insufficient.
G WARNING
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.
X Carefully drive a suitable distance, making slight steering
movements at a speed above 12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. ÷
Inoperative See Inoperative See
Operator's Manual Operator's Manual ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilization are unavailable due to a malfunction.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷andå warning lamps light up in the
instrument cluster.
The self-diagnosis function might not be complete, for example.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. 236
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M
MSolutions The braking distance in an emergency braking situation can thus
increase.
If ESP
®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive a suitable distance, making slight steering
movements at a speed above 12 mph (20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. T!
÷
Inoperative See Inoperative See
Operator's Manual Operator's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, PRE-
SAFE ®
, the HOLD function, hill start assist and ESP ®
trailer
stabilization are unavailable due to a malfunction.
BAS PLUS and PRE-SAFE ®
Brake may also have failed.
In addition, the ÷,åand! warning lamps light up in
the instrument cluster and a warning tone sounds.
G WARNING
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.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. F(USA
only)
J(Canada
only)
Please Release Please Release
Parking Brake Parking Brake You are driving with the parking brake applied. A warning tone also
sounds.
X
Release the parking brake. Display
messages
237On-board computer and displays Z
Safety systems
Problem Possible causes/consequences and
M
MSolutions $
(USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds. There is not enough brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 164).
X Do not add brake fluid. Topping up will not remedy the
malfunction.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The yellow ABS warning
lamp is lit while the
engine is running.
ABS (Anti-lock Brake System) is deactivated due to a malfunction.
BAS (Brake Assist), BAS PLUS, ESP
®
(Electronic Stability
Program), PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD function, hill
start assist and ESP ®
trailer stabilization are therefore also
deactivated, for example.
ATTENTION ASSIST is deactivated.
G WARNING
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.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
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. Warning and indicator lamps in the instrument cluster
263On-board computer and displays Z
Problem Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running.
ABS is temporarily unavailable. BAS, BAS PLUS, ESP
®
, EBD
(electronic brake force distribution), PRE-SAFE ®
,
PRE-SAFE ®
Brake, the HOLD function, hill start assist and
ESP ®
trailer stabilization are therefore also deactivated, for
example.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
ATTENTION ASSIST is deactivated.
G WARNING
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 a risk of an accident.
X Carefully drive a suitable distance, making slight steering
movements at a speed above 12 mph (20 km/h).
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 264
Warning and indicator lamps in the instrument clusterOn-board computer and displays