
You can activate or deactivate Active Brake
Assist (Ypage 163) in the on-board computer.
When deactivated, the distance warning func-
tion and the autonomous braking function are
also deactivated.
If Active Brake Assist is deactivated, the æ
symbol appears in the assistance graphic dis-
play.
Distance warning function
General information
The distance warning function can help you to
minimize the risk of a front-end collision with a
vehicle ahead or reduce the effects of such a
collision. If the distance warning function
detects that there is a risk of a collision, you will
be warned visually and acoustically.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 57).
GWARNING
The distance warning function does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen cornering
The distance warning function may not give
warnings in all critical situations. There is a
risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
Always adapt your speed to suit the prevailing
road and traffic conditions.
GWARNING
The distance warning function cannot always
clearly identify objects and complex traffic
situations.
In such cases, the distance warning function
may:
Rgive an unnecessary warning
Rnot give a warning
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and do not rely solely on the distance
warning function.
Function
Starting at a speed of approximately 4 mph
(7 km/h), the distance warning function warns
you if you rapidly approach a vehicle in front. Anintermittent warning tone will then sound, and
the · distance warning lamp will light up in
the instrument cluster.
XBrake immediately in order to increase the
distance from the vehicle in front.
or
XTake evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the system to display a warning.
With the help of the radar sensor system, the
distance warning function can detect obstacles
that are in the path of your vehicle for an exten-
ded period of time.
Up to a speed of approximately 44 mph
(70 km/h), the distance warning function can
also react to stationary obstacles, such as stop-
ped or parked vehicles.
Autonomous braking function
If the driver does not react to the distance warn-
ing signal in a critical situation, Active Brake
Assist can assist the driver with the autonomous
braking function.
The autonomous braking function:
Rgives the driver more time to react to critical
driving situations
Rcan help the driver to avoid an accident or
Rreduces the effects of an accident
Vehicles without Distance Pilot DISTRONIC: the autonomous braking function is available in
the following speed ranges:
R4 - 65 mph (7 - 105 km/h) for moving objects
R4 - 31 mph (7 - 50 km/h) for stationary
objects
Driving safety systems59
Safety
Z

Vehicles with Distance Pilot DISTRONIC:the
autonomous braking function is available in the
following speed ranges:
R4 - 124 mph (7 - 200 km/h) for moving
objects
R4 - 31 mph (7 - 50 km/h) for stationary
objects
Due to the nature of the system, particularly
complicated but non-critical driving conditions
may also cause the Autonomous Braking Func-
tion to intervene.
If the autonomous braking function requires a
particularly high braking force, preventative
passenger protection measures (PRE-SAFE
®)
are activated simultaneously (Ypage 53).
Situation-dependent braking assis-
tance
General information
iObserve the "Important safety notes" sec-
tion (Ypage 57).
With the help of the radar sensor system, Active Brake Assist can detect obstacles that are in the
path of your vehicle for an extended period of
time.
If Active Brake Assist detects a risk of collision
with the vehicle in front, it calculates the brake
pressure necessary to avoid a collision. If you
apply the brakes forcefully, situation-dependent
braking assistance adapts to the situation and
automatically increases the brake pressure to a
degree appropriate to the traffic situation.
Situation-dependent braking assistance pro-
vides braking assistance in hazardous situations
at speeds above 4 mph (7 km/h). It uses radar
sensor technology to assess the traffic situa-
tion.
Situation-dependent braking assistance is capa-
ble of reacting to moving objects that have
already been detected as such at least once
over the period of observation, up to vehicle
speeds of around 155 mph (250 km/h).
Situation-dependent braking assistance reacts
to stationary obstacles up to a speed of approx-
imately 44 mph (70 km/h).
If situation-dependent braking assistance
demands particularly high brake pressure, pre-
ventative passenger protection measures (PRE-
SAFE
®) are triggered simultaneously
(Ypage 53).
XKeep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
Ryou release the brake pedal
Rthere is no longer any danger of a collision
Rno obstacle is detected in front of your vehicle
Situation-dependent braking assistance is then
deactivated.
Important safety notes
iObserve the "Important safety notes" sec-
tion for driving safety systems (Ypage 57).
GWARNING
Adaptive Brake Assist does not react:
Rto people or animals
Rto oncoming vehicles
Rto crossing traffic
Rwhen cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake.
GWARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist might:
Rintervene unnecessarily
Rnot intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit- uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
Due to the nature of the system, complex but
non-critical driving conditions may also cause
Active Brake Assist to intervene.
Even if Active Brake Assist is not available due to
a malfunction in the radar sensor system, the
brake system is still available with full brake
boosting effect and BAS.
60Driving safety systems
Safety

SmartKey
Important safety notes
GWARNING
If children are left unsupervised in the vehicle,
they could:
Ropen the doors, thus endangering other
people or road users.
Rget out and disrupt traffic.
Roperate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
Rrelease the parking brake.
Rshifting the automatic transmission out of
park position P
RStart the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
GWARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
!Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the SmartKey:
Rwith electronic devices, e.g. a mobile phone
or another SmartKey
Rwith metallic objects, e.g. coins or metal foil
Rinside metallic objects, e.g. a metal case
This can affect the functionality of the Smart-
Key. Vehicles with KEYLESS-GO start function:
do
not keep the SmartKey on the cargo compart-
ment cover or in the cargo compartment. Oth-
erwise, the SmartKey may not be detected, e.g.
when starting the engine using the Start/Stop
button.
A brief radio connection between the vehicle
and the SmartKey determines whether a valid
SmartKey is in, or in the direct vicinity of, the
vehicle. This occurs, for example:
Rwhen starting the engine
Rwhile driving
Rwhen using the tailgate unlocking sensor
Rwhen the external door handles are touched
Rduring convenience closing
SmartKey functions
:& Locks the vehicle
;FOpens the tailgate
=%Unlocks the vehicle
XTo unlock centrally: press the%button.
If you do not open the vehicle within approx-
imately 40 seconds of unlocking:
Rthe vehicle is locked again
Rthe anti-theft alarm system is armed again.
XTo lock centrally: press the&button.
The SmartKey centrally locks and unlocks the
doors and the fuel filler flap.
The turn signals flash once when unlocking and
three times when locking.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated via the
multimedia system; see the Digital Operator's
Manual.
SmartKey65
Opening and closing
Z

When the locator lighting is activated via the
multimedia system, it lights up when it is dark
after the vehicle is unlocked with the SmartKey.
Information on activating and deactivating the
locator lighting can be found in the Digital Oper-
ator's Manual.
XTo open the tailgate:press and hold the
F button until the tailgate opens.
KEYLESS-GO
General notes
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle (
Ypage 107).
Locking/unlocking centrally
You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry the
SmartKey with you. You can combine the func-
tions of KEYLESS-GO with those of a conven-
tional SmartKey. Unlock the vehicle by using
KEYLESS-GO, for instance, and lock it using the
& button on the SmartKey.
The driver's door and the door at which the han-
dle is used, must both be closed. The SmartKey
must be outside the vehicle. When locking or
unlocking with KEYLESS-GO, the distance
between the SmartKey and the corresponding
door handle must not be greater than 3 ft (1 m).
A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example:
Rwhen starting the engine
Rwhile driving
Rwhen using the tailgate unlocking sensor
Rwhen the external door handles are touched
Rduring convenience closing
XTo unlock the vehicle: touch the inner sur-
face of the door handle.
XTo lock the vehicle: touch sensor surface :
or ;.
Make sure that you do not touch the inner
surface of the door handle.
XConvenience closing feature: touch
recessed sensor surface ;for an extended
period.
Further information on the convenience clos-
ing feature (
Ypage 77).
Deactivating and activating
If you do not intend to use the vehicle for a lon-
ger period of time, you can deactivate KEYLESS-
GO. The SmartKey will then use very little power,
thereby conserving battery power. For the pur-
poses of activation/deactivation, the vehicle
must not be nearby.
XTo deactivate: press the&button on the
SmartKey twice in rapid succession.
The indicator light on the SmartKey flashes
twice briefly then one long flash, then KEY-
LESS-GO is deactivated (
Ypage 68).
XTo activate: press any button on the Smart-
Key.
or
XInsert the SmartKey into the ignition lock.
KEYLESS-GO and all of its associated features
are available again.
KEYLESS-GO start function
Bear in mind that the engine can be started by
any of the vehicle occupants if there is a Smart-
Key in the vehicle (
Ypage 107).
66SmartKey
Opening and closing

Changing the settings of the locking
system
You can change the settings of the locking sys-
tem. This means that only the driver's door and
the fuel filler flap are unlocked when the vehicle
is unlocked. This is useful if you frequently travel
on your own.
XTo change the setting:press and hold down
the % and& buttons simultaneously
for about six seconds until the battery indica-
tor lamp flashes twice (
Ypage 68).
If the setting of the locking system is changed
within the signal range of the vehicle, pressing
the & or% button:
Rlocks or
Runlocks the vehicle
The SmartKey now functions as follows:
XTo unlock: press the%button once.
XTo unlock centrally: press the%button
twice.
XTo lock: press the &button.
The KEYLESS-GO functions can be changed as
follows:
XTo unlock the driver's door: touch the inner
surface of the door handle on the driver's
door.
XTo unlock centrally: touch the inner surface
of the front-passenger door handle.
XTo lock centrally: touch the outer sensor
surface on one of the door handles.
Restoring factory settings:
XPress the %and& buttons simultane-
ously for approximately six seconds until the
battery check lamp flashes twice
(
Ypage 68).
Mechanical key
General notes
If the vehicle can no longer be locked or
unlocked with the SmartKey or KEYLESS-GO,
use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm sys-
tem will be triggered. Switch off the alarm
(
Ypage 63). If you unlock the vehicle using the mechanical
key, the fuel filler flap will not be unlocked auto-
matically.
XTo unlock the fuel filler flap:
insert the
SmartKey into the ignition lock.
Removing the mechanical key
XPush release catch :in the direction of the
arrow and at the same time remove mechan- ical key ;from the SmartKey.
For further information about:
Runlocking the driver's door (Ypage 72)
Rlocking the vehicle (Ypage 72)
Inserting the mechanical key
XPush mechanical key ;completely into the
SmartKey until it engages and release
catch :is back in its basic position.
SmartKey battery
Important safety notes
GWARNING
Batteries contain toxic and corrosive substan- ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatalinjury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
SmartKey67
Opening and closing
Z

kicking movement only within the detection
range of the sensors.
!If the SmartKey is within the rear detection
range of KEYLESS-GO, the following situa-
tions, for example, could lead to the uninten-
tional opening of the tailgate:
Rwhen using an automatic car wash
Rwhen using a power washer
Make sure that the SmartKey is at least 10 ft
(3 m) away from the vehicle.
General notes
Vehicles with KEYLESS-GO without carbon
package: you can unlock the tailgate without
using your hands. This is useful if you have your
hands full. To do this, make a kicking movement
under the rear bumper with your foot.
Observe the following points:
RCarry your KEYLESS-GO key about your per-
son. The SmartKey must be at the rear of the
vehicle in the detection range of KEYLESS-
GO.
RWhen making the kicking movement, make
sure that you are standing firmly on the
ground and that there is sufficient clearance
to the rear of the vehicle. You could otherwise
lose your balance, for example on ice.
RAlways ensure that you only make the kicking
movement within the detection range of sen-
sors :.
RStand at least 12 in (30 cm) away from the
rear area while doing so.
RDo not come into contact with the bumper
while making the kicking movement. Other-
wise, the sensors may not function correctly.
RUnlocking the tailgate via the sensor does not
function while the engine is being started.
RDirt caused by road salt or snow around sen-
sors :may restrict functionality.
Using the tailgate unlocking function via the
sensor with a prosthetic leg may restrict func- tionality.
RIf a KEYLESS-GO SmartKey is within the rear
detection range of KEYLESS-GO, the sensors
could be triggered. As a result, the tailgate
could be opened unintentionally under the
following conditions:
-if you set something down or lift something
behind the vehicle
-if you polish the rear of the vehicle
Do not carry the KEYLESS-GO key about your
person in these situations or in situations sim-
ilar to these. This prevents the tailgate from
being unlocked unintentionally.
Operation
XTo unlock: kick into sensor detection
range :below the bumper with your foot.
The tailgate opens slightly.
XTo open: lift the tailgate.
XIf the tailgate does not unlock after sev-
eral attempts: wait at least ten seconds and
then kick under the bumper once again.
If you hold your foot under the bumper for too
long, the tailgate does not unlock. Repeat the
leg movement more quickly if this occurs.
Unlocking from inside the vehicle
GWARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. If the tailgate is open when the engine is running, particu-
larly if the vehicle is moving, exhaust fumes
74Cargo compartment
Opening and closing

could enter the passenger compartment.
There is a risk of poisoning.
Turn off the engine before opening the tail-
gate. Never drive with the tailgate open.
You can open the tailgate from the driver's seat
when the vehicle is stationary and unlocked.
XPress remote operating switch:for the tail-
gate until the tailgate is unlocked.
The tailgate opens slightly.
Tailgate emergency release
Use the emergency release if the tailgate can no
longer be unlocked:
Rusing the SmartKey
Rwith the tailgate unlocking sensor
Rusing the remote operating switch on the
instrument panel
XClimb into the cargo compartment via the
vehicle interior.
Unhook the cargo compartment cover, if nec-
essary (
Ypage 215).
XPush carpet :down.
XPull the cable behind carpet :until the tail-
gate unlocks.
The tailgate opens slightly.
XLift the tailgate.
When you close the tailgate, it is also locked at
the same time.
Side windows
Important safety notes
GWARNING
While opening the side windows, body parts
could become trapped between the side win-
dow and the door frame as the side window
moves. There is a risk of injury.
Make sure that nobody touches the side win-
dow during the opening procedure. If some-
body becomes trapped, release the switch or
pull the switch to close the side window again.
GWARNING
While closing the side windows, body parts in
the closing area could become trapped. There is a risk of injury.
When closing make sure that no parts of the
body are in the closing area. If somebody
becomes trapped, release the switch or press
the switch to open the side window again.
GWARNING
If children operate the side windows they
could become trapped, particularly if they are left unsupervised. There is a risk of injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
Side window reversing feature
The side windows are equipped with an auto-
matic reversing feature. If a solid object blocks
or restricts a side window from traveling
upwards during the automatic closing process,
the side window opens again automatically. Dur-
ing the manual closing process, the side window
Side windows75
Opening and closing
Z

Convenience closing feature
Important safety notes
GWARNING
When using the convenience closing feature,
parts of the body could be trapped in the clos-
ing area when a side window is being closed.
There is a risk of injury.
Observe the complete closing procedure
when the convenience closing feature is oper-
ating. Make sure that no body parts are in
close proximity during the closing procedure.
When you lock the vehicle, you can close the
windows at the same time.
Using the SmartKey
XPress and hold the &button until the side
windows are fully closed.
XMake sure that all the side windows are
closed.
XTo interrupt convenience closing: release
the & button.
Using KEYLESS-GO
The driver's door and the door at which the han-
dle is used, must both be closed. The SmartKey
must be outside the vehicle. The gap between
the SmartKey and the corresponding door han-
dle should not be greater than 3 ft (1 m).
XTouch recessed sensor surface :on the
door handle until the side windows are fully
closed.
Make sure you only touch recessed sensor
surface :.
XMake sure that all the side windows are
closed.
XTo interrupt convenience closing: release
recessed sensor surface :on the door han-
dle.
Resetting the side windows
If a side window can no longer be closed fully,
you must reset it.
XClose all the doors.
XSwitch on the power supply or switch on the
ignition with the Start/Stop button.
XPull the corresponding switch on the door
control panel until the side window is com-
pletely closed (
Ypage 76).
XHold the switch for an additional second.
If the side window opens again slightly:
XImmediately pull the corresponding switch on
the door control panel until the side window is
completely closed (
Ypage 76).
XHold the switch for an additional second.
XIf the respective side window remains closed
after the button is released, then it has been
set correctly. If this is not the case, repeat the
steps above.
Side windows77
Opening and closing
Z