
cialist workshop or to a col-
lection point for used batter-
ies.
Have the batteries changed at a qualified spe-
cialist workshop.
Checking the battery X
Press the &or% button.
The battery is working properly if battery
check lamp :lights up briefly.
The battery is discharged if battery check
lamp :does not light up briefly.
X Change the battery (Y page 74).
i If the key battery is checked within the
signal receptio nrange of the vehicle, press-
ing the &or% button:
R locks or
R unlocks the vehicle
i You can get a battery in any qualified spe-
cialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X
Take the emergency key elemen tout of the
key (Y page 73). X
Press emergency key element ;into the
opening in the key in the direction of the
arrow until battery tray cover :opens.
When doing so, do no thold cover :shut.
X Remove battery tray cover :. X
Repeatedly tap the key against your palm
until battery =falls out.
X Insert the new battery with the positive ter-
minal 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 tray
cover :and then press to close it.
X Insert the emergency key element into the
key.
X Check the function of all key buttons on the
vehicle. 74
KeyOpening and closing

i
If depressing the brake pedalt he first
time does not activate the HOLD function,
wait briefly and then try again.
Deactivating the HOLD function The HOLD function is deactivated automati-
cally if:
R you accelerate and the transmission is in
position Dor R.
R you shift the transmission to position P.
R you depress the brake pedal again with a
certain amount of pressure until ëdis-
appears from the multifunction display.
R you secure the vehicle using the electric
parking brake.
R you activate DISTRONIC PLUS.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
The electric parking brake secures the vehicle
automatically if the HOLD function is activa-
ted and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the engine is switched off, unless it is auto-
matically switched off by the ECO start/
stop function.
R a system fault occurs.
R the power supply is not sufficient.
If a fault occurs, then the transmission may
be shifted into position Pautomatically. PARKTRONIC
Important safety notes G
WARNING
PARKTRONIC is only an aid and may not
detect all obstacles. It is not a substitute for
attentive driving.
You are always responsible for safety and
must continue to pay attention to your imme-
diate surroundings when parking and manoeuvring. You could otherwise endanger
yourself and others.
G
WARNING
Make sure that no persons or animals are in
the manoeuvring range. Otherwise, they
could be injured.
! When parking, pay particular attention to
objects above or below the sensors, such
as flower pots or trailer drawbars. PARK-
TRONIC 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
objects which absorb ultrasonic sources.
Ultrasonic sources, such as an automatic
car wash, a lorry's compressed-air brakes
or a pneumatic drill, could cause PARK-
TRONIC to malfunction.
PARKTRONIC may not function correctly on
uneven terrain.
PARKTRONIC is an electronic parking aid with
ultrasonic sensors. It indicates visually and
audibly the distance between your vehicle
and an object.
PARKTRONIC is activated automatically if
you:
R switch on the ignition
R shift to position D,Ror Non vehicles with
automatic transmission
R release the electric parking brake
PARKTRONIC is deactivated at speeds above
18 km/h. It is reactivated at lower speeds.
PARKTRONIC monitors the area around your
vehicle using six sensors in the front bumper
and four sensors in the rear bumper. Driving systems
163Driving and parking Z

When
Standard is selected, no warning vibra-
tion 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 is selected, no warning vibra-
tion occurs if:
R you have switched on the turn signals. In
this case, the warnings are suppressed for
a certain period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lane quickly.
R you 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 recognises certain con-
ditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a motor-
way.
R the system recognises solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend. Towing
atrailer Notes on towing
atrailer
Important safety notes G
WARNING
When reversing the vehicle towards the
trailer, make sure there is nobody between
the trailer and the vehicle. Couple and uncouple the trailer carefully
.If
you do no tcouple the trailer to the towing
vehicle correctly, the trailer could become
detached.
Make sure that the following values are not
exceeded:
R the permissible trailer drawbar noseweight
R the permissible trailer load
R the permissible rear axle load of the towing
vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
You will find the applicable permissible val-
ues, which must not be exceeded, in the vehi-
cle documents.
You will find the values approved by the man-
ufacturer on the vehicle identification plates
and those for the towing vehicle in the "Tech-
nical data" section. G
WARNING
If the Check trailer hitch locking mechanism message appears in the multi-
function display while the vehicle is in motion,
pull over immediately and check whether the
ball coupling is correctly engaged. G
WARNING
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
to when driving without a trailer.
The vehicle/trailer combination:
R is heavier
R is restricted in its acceleration and gradi-
ent-climbing capability
R has an increased braking distance
R is affected more by strong crosswinds
R demands more sensitive steering
R has a larger turning circle
As a result, the handling characteristics may
be impaired and you may lose control of the
vehicle. This could lead to an accident with
serious or even fatal injuries. Towing
atrailer
181Driving an d parking
Z

Safety systems
Display messages Possible causes/consequences and
M Solutions
!÷
currently unavail‐
able See Owner's
Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability Pro-
gram), BAS (Brake Assist), PRE-SAFE ®
, the HOLD function, hill
start assist and ESP ®
trailer stabilisation are temporarily not avail-
able.
The adaptive brake lights and BAS PLUS may also have failed.
In addition, the ÷,åand! warning lamps light up in
the instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes:
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.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above 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
Owner's Manual ABS, ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist
and ESP ®
trailer stabilisation are not available due to a malfunc-
tion.
The adaptive brake lights and BAS PLUS may also have failed.
In addition, the J,÷,åand! warning lamps light
up in the instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING 206
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
÷
inoperative See
Owner's Manual ESP
®
, BAS, PRE-SAFE ®
, the HOLD function, hill start assist and
ESP ®
trailer stabilisation are no tavailable due to a malfunction.
The adaptive brake lights and BAS PLUS may also have failed.
In addition, the ÷andå warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Drive on carefully.
X Visi taqualified specialist workshop. T!
÷
inoperative See
Owner's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, PRE-
SAFE ®
, the HOLD function ,hill start assist and ESP ®
trailer stabi-
lisatio nare not available due to a malfunction.
The adaptive brake lights and BAS PLUS may also have failed.
In addition, the ÷,åand! warning lamps in the instru-
ment cluster light up and a warning tone sounds.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but withou tthe
functions listed above. The wheels could therefore lock if you
brake hard, for example.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. !
Release parking
brake The red
!indicator lamp flashes and a warning tone sounds.
A condition for automatic release of the electric parking brake is
not fulfilled (Y page 145).
You are driving with the electric parking brake applied.
X Release the electric parking brake manually. 208
Display messagesOn-board computer and displays

Safety systems
Problem Possible causes/consequences and
M Solutions
J
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds. There is insufficient brake fluid in the brake fluid reservoir.
G WARNING
The braking effect may be impaired.
There is a risk of 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 Engage the electric parking brake.
X Do not top up the brake fluid. Topping up will not remedy the
fault.
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) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
, the HOLD function, hill start assist,
the adaptive brake lights and ESP ®
trailer stabilisation are 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.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of 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 trans-
mission, will not be available. Warning and indicator lamps in the instrument cluster
233On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. ABS is temporarily unavailable. Therefore, BAS, BAS PLUS, ESP
®
,
EBD (electronic brake force distribution), PRE-SAFE ®
, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are also deactivated.
Possible causes:
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 wheels could therefore lock if you
brake hard, for example.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Carefully drive on a suitable stretch of road, making slight steer-
ing movements, at a speed above 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. 234
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
!
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds. EBD is faulty. Therefore, ABS,B
AS, BAS PLUS, ESP®
, PRE-SAFE ®
,
the HOLD function, hill start assist, the adaptive brake lights and
ESP ®
trailer stabilisation, for example, are not available either.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continue sto function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. J֌!
The red brake warning
lamp, the yellow ESP
®
and ESP ®
OFF warning
lamps and the yellow
ABS warning lamp are
lit while the engine is
running. ABS and ESP
®
are malfunctioning. Therefore, BAS, BAS PLUS,
EBD,P RE-SAFE ®
, the HOLD function ,hill start assist, the adaptive
brake lights and ESP ®
trailer stabilisation, for example, are not
available either.
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.
This limits the steerability of the vehicle when braking and may
increase the braking distance.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
235On-board computer and displays Z