
Function
The distance warning function issues a warn-
ing at speeds:
R of approximately 30 km/h or more, if, over
several seconds, the distance maintained
to the vehicle travelling in front is insuffi-
cient. The ·distance warning lamp
then lights up in the instrument cluster.
R of approximately 7 km/h or more, if you
rapidly approach a vehicle in front. An inter-
mittent warning tone will then sound, and
the · distance warning lamp will light
up in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause the system to display a
warning.
With the help of the radar sensor system, the distance warning function can detect obsta-
cles that are in the path of your vehicle for an
extended period of time.
Up to a speed of approximately 70 km/h, the
distance warning function can also react to
stationary obstacles, such as stopped or
parked vehicles.
Autonomous braking function If the driver does not react to the distance
warning signal in a critical situation, COLLI-
SION PREVENTION ASSIST PLUS can assist
with the autonomous braking function.
The autonomous braking function:
R gives the driver more time to react to criti-
cal driving situations
R can help the driver to avoid an accident or
R reduces the effects of an accident Vehicles without DISTRONIC PLUS:
the
autonomous braking function is available in
the following speed ranges:
R 7 - 105 km/h for moving objects
R 7 - 50 km/h for stationary objects
Vehicles with DISTRONIC PLUS: the auton-
omous braking function is available in the fol- lowing speed ranges:
R 7 - 200 km/h for moving objects
R 7 - 50 km/h for stationary objects
Due to the nature of the system, complicated
but non-critical driving conditions may also
cause the Autonomous Braking function to
intervene.
If the autonomous braking function demands particularly high braking force, preventative
passenger protection measures (PRE-SAFE ®
)
are activated simultaneously (Y page 63).
Adaptive Brake Assist General notes
i Observe the "Important safety notes" sec-
tion (Y page 78).
With the help of Adaptive Brake Assist, the
distance warning signal can detect obstacles
that are in the path of your vehicle for an
extended period of time.
If Adaptive Brake Assist detects a risk of a
collision with the vehicle in front, it calculates
the braking force necessary to avoid a colli-
sion. If you apply the brakes forcefully, Adap-
tive Brake Assist will automatically increase
the braking force to a level suitable for the
traffic conditions.
Adaptive Brake Assist provides braking assis- tance in hazardous situations at speeds
above 7 km/h. It uses radar sensor technol-
ogy to assess the traffic situation.
Up to a speed of approximately 250 km/h,
Adaptive Brake Assist is capable of reacting
to moving objects that have already been
detected as such at least once over the period
of observation. Driving safety systems
83Safety Z

Up to a speed of approximately 70 km/h,
Adaptive Brake Assist reacts to stationary
obstacles.
If the autonomous braking function demands particularly high braking force, preventative
passenger protection measures (PRE-SAFE ®
)
are activated simultaneously (Y page 63). On
vehicles with the Driving Assistance package,
preventive passenger protection measures
(PRE-SAFE ®
PLUS) are triggered (Y page 64).
X Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if:
R you release the brake pedal
R there is no longer any danger of a collision
R no obstacle is detected in front of your
vehicle
Adaptive Brake Assist is then deactivated.
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems (Y page 78).G
WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist can:
R intervene unnecessarily
R not 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. G
WARNING
Adaptive Brake Assist does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering As a result, the 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.
Due to the nature of the system, particularly
complicated but non-critical driving condi-
tions may also cause Brake Assist to inter-
vene.
If Adaptive Brake Assist is not available due to a malfunction in the radar sensor system, thebrake system remains available with full
brake boosting effect and BAS. Adaptive brake lights
The adaptive brake lights warn following traf- fic in an emergency braking situation:
R by flashing brake lamps
R by activating the hazard warning lamps
If you brake sharply from a speed of more
than 50 km/h or if braking is assisted by BAS
or BAS PLUS, the brake lamps flash rapidly. In this way, traffic travelling behind you is
warned in an even more noticeable manner.
If you brake sharply from a speed of more
than 70 km/h to a standstill, the hazard warn-
ing lamps are activated automatically. If the
brakes are applied again, the brake lamps
light up continuously. The hazard warning
lamps switch off automatically if you travel
faster than 10 km/h. You can also switch off
the hazard warning lamps using the hazard
warning button (Y page 141). ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes" sec-
tion (Y page 78).
ESP ®
monitors driving stability and traction,
i.e. power transmission between the tyres
and the road surface. 84
Driving safety systemsSafety

If ESP
®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilise the
vehicle. The engine output is also modified to keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilise the vehicle during braking.
4ETS (Electronic Traction System) i
Observe the "Important safety notes" sec-
tion (Y page 78).
4ETS traction control is part of ESP ®
.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is trans-
ferred to the wheel or wheels with traction.
Traction control remains active if you deacti-
vate ESP ®
.
Off-road 4ETS (Electronic Traction Sys-
tem) A 4ETS system specifically suited to off-road
terrain is activated automatically once the off- road program is activated (Y page 250).
Off-road ESP ® An ESP
®
system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated (Y page 250).
The off-road ESP ®
intervenes with a delay if
there is oversteering or understeering, thus
improving traction.
Important safety notes i
Observe the "Important safety notes" sec-
tion (Y page 78). G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilise the vehicle. In addition, other driving safety systems are switched off. This increa-
ses the risk of skidding and an accident.
Drive on carefully. Have ESP
®
checked at a
qualified specialist workshop.
If the å ESP®
OFF warning lamp lights up
continuously, ESP ®
is deactivated.
If the ÷ ESP®
warning lamp lights up con-
tinuously, ESP ®
is not available due to a mal-
function.
Observe the information on warning lamps
(Y page 381) and display messages which
may be shown in the instrument cluster
(Y page 336).
Only use wheels with the recommended tyre
sizes. Only then will ESP ®
function properly.
Characteristics of ESP ® General notes
If the
÷ ESP warning lamp goes out before
beginning the journey, ESP ®
is automatically
active.
If ESP ®
intervenes, the ÷ESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any circum-
stances.
X When pulling away, only depress the accel-
erator pedal as far as is necessary.
X Adapt your driving style to suit the prevail-
ing road and weather conditions.
ECO start/stop function
The ECO start/stop function switches the
engine off automatically if the vehicle stops
moving. When pulling away again, the engine starts automatically. ESP ®
remains in its pre-
viously selected status. Example:if ESP®
was deactivated before the engine was
switched off, ESP ®
remains deactivated when
the engine is switched on again. Driving safety systems
85Safety Z

Deactivating/activating ESP
®Important safety notes
i Observe the "Important safety notes" sec-
tion (Y page 78).
You can select between the following sta-
tuses of ESP ®
:
R ESP ®
is activated
R ESP ®
is deactivated G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilises the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following.
It may be best to deactivate ESP ®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
R when driving off-road (vehicles without off-
road program)
Activate ESP ®
as soon as the situations
described above no longer apply. ESP ®
will
otherwise not be able to stabilise the vehicle if the vehicle starts to skid or a wheel starts to
spin.
Deactivating/activating ESP ®X
To deactivate: press button:.
The å ESP®
OFF warning lamp in the
instrument cluster lights up. X
To activate: press button :.
The å ESP®
OFF warning lamp in the
instrument cluster goes out.
Characteristics when ESP ®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ESP®
warning lamp in
the instrument cluster flashes. In such situa-
tions, ESP ®
will not stabilise the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability
R engine torque is no longer limited and the
drive wheels are able to spin
The spinning of the wheels results in a cut-
ting action for better traction on loose sur- faces.
R Traction control is still activated
R COLLISION PREVENTION ASSIST is no lon-
ger available; nor is it activated if you brake
firmly with assistance from ESP ®
R PRE-SAFE ®
is no longer available; it is also
not activated if you brake firmly with assis-
tance from ESP ®
R PRE-SAFE ®
Brake is no longer available; it
is also not activated if you brake firmly with
assistance from ESP ®
R ESP ®
still provides support when you brake
firmly
ESP ®
trailer stabilisation General notes
If your vehicle/trailer combination begins to
lurch, ESP
®
assists you in this situation. ESP ®
slows the vehicle down by braking and limit-
ing the engine output until the vehicle/trailer combination has stabilised.
Important safety notes G
WARNING
If road and weather conditions are poor,
trailer stabilisation will not be able to prevent the vehicle/trailer combination from swerv-
ing. Trailers with a high centre of gravity can 86
Driving safety syste
msSafety

R
darkness
R if:
- pedestrians move quickly, e.g. into the
path of the vehicle
- the camera system no longer detects a
pedestrian as a person due to special
clothing or other objects
- a pedestrian is concealed by other
objects
- the typical outline of a person is not dis-
tinguishable from the background
Following damage to the front end of the vehi-
cle, have the radar sensor settings and oper- ation checked at a qualified specialist work-
shop. This also applies to collisions at slow
speeds where there is no visible damage to
the front of the vehicle.
Following damage to the windscreen, have
the configuration and operation of the cam-
era system checked at a qualified specialist
workshop.
Function X
To activate/deactivate: activate or deac-
tivate PRE-SAFE ®
Brake in the on-board
computer (Y page 328).
If the PRE-SAFE ®
Brake is not activated, the
æ symbol appears in the multifunction
display.
If you have activated DSR (Y page 248) PRE-
SAFE ®
Brake is also deactivated.
This function will issue a warning if:
R at a speed of around 30 km/ hor more, the
distance maintained to the vehicle travel-
ling in front is insufficient for several sec-
onds
The · distance warning lamp then lights
up in the instrument cluster.
R at a speed of around 7 km/h or more, you
rapidly approach a vehicle in front or a
pedestrian
An intermittent warning tone will then
sound and the ·distance warning lamp
lights up in the instrument cluster. X
Brake immediately to defuse the situation.
or
X Take evasive action provided it is safe to do
so.
The PRE-SAFE ®
Brake function can also brake
the vehicle automatically under the following
conditions:
R the driver and front passenger have their
seat belts fastened
and
R the vehicle speed is between approx-
imately 7 km/h and 200 km/h
At a speed of up to approximately 70 km/h,
PRE-SAFE ®
Brake can also detect:
R stationary objects in the path of your vehi-
cle, e.g. stopped or parked vehicles
R pedestrians in the path of your vehicle
i If there is an increased risk of a collision,
preventive passenger protection measures
(PRE-SAFE ®
) are activated (Y page 64).
If the risk of a collision with the vehicle in front remains and you do not brake, take evasive
action or accelerate significantly, the vehicle
may perform automatic emergency braking,
up to the point of full brake application. Auto-
matic emergency braking is not performed
until immediately prior to an imminent acci-
dent.
You can prevent the intervention of PRE-
SAFE ®
Brake at any time by:
R depressing the accelerator pedal further
R activating kickdown
R releasing the brake pedal
The braking action of PRE-SAFE ®
Brake is
ended automatically if:
R you manoeuvre to avoid the obstacle
R there is no longer a risk of collision
R there is no longer an obstacle detected in
front of your vehicle Driving safety systems
89Safety Z

Problem
Possible causes/consequences and
M
MSolutions The engine cannot be
started using the key. The on-board voltage is too low.
X Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 441).
or
X Jump-start the vehicle (Y page 443).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the Start/
Stop button. The key is
in the vehicle. The vehicle is locked.
X Unlock the vehicle and try to start the vehicle again. The key battery is discharged or nearly discharged.
X Check the key battery (Y page 98) and replace it if necessary
(Y page 98).
If this does not work: X Start your vehicle with the key in the ignition lock. There is interference from a powerful source of radio waves.
X Start your vehicle with the key in the ignition lock. You have lost a key. X
Have the key deactivated at a qualified specialist workshop.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the emer-
gency key element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. Doors
Important safety notes
United Kingdom only: G
WARNING
When the double locks are activated, the
doors can no longer be opened from the
inside. People in the vehicle can no longer get out, e.g. in hazardous situations. There is a
risk of injury. Therefore, do not leave any people unsuper-
vised in the vehicle, particularly children, eld- erly people or people in need of special assis-
tance. Do not activate the double lock when
people are in the vehicle.
If the vehicle has been locked from the out-
side, the double lock function is activated as
standard. It is then not possible to open the
doors from inside the vehicle. You can deac-
tivate the double lock function by deactivat-
ing the interior motion sensor (see the sepa- 100
DoorsOpening and closing

X
Insert the emergency key element into the
lock of the driver's door as far as it will go.
X Turn the emergency key element clockwise
as far as it will go to position 1.
The locking knob drops down and the driv- er's door is locked.
On right-hand-drive vehicles, turn the emer-
gency key element anti-clockwise.
X Turn the emergency key element back and
remove it.
X Insert the emergency key element into the
key (Y page 97).
X Make sure that the doors and the tailgate
are locked.
X Carefully press the protective cap onto the
lock cylinder until it engages and is seated firmly. Do not pull the door handle when
doing so.
If you lock the vehicle as described above, the
fuel filler flap is not locked. The anti-theft
alarm system is not primed. Luggage compartment
Important safety notes
G
WARNING
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
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. G
WARNING
If objects, luggage or loads are not secured or not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, especially when braking or abruptly changing directions.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
! The tailgate swings upwards and to the
rear when opened. Therefore, make sure
that there is sufficient clearance above and behind the tailgate.
The opening dimensions of the tailgate can be
found in the "Vehicle data" section
(Y page 488).
You can limit the opening angle of the tailgate
(Y page 108).
Do not leave the key in the luggage compart- ment. You could otherwise lock yourself out.
Stow luggage or loads preferably in the lug-
gage compartment. Observe the loading
guidelines (Y page 390). Tailgate obstruction detection with
reversing function
Vehicles with remote tailgate closing fea- ture: the tailgate is equipped with automatic
obstacle recognition with a reversing feature. If a solid object blocks or restricts the tailgate
when automatically opening, this procedure
is stopped. If a solid object blocks or restricts the tailgate when automatically closing, the
tailgate automatically opens again slightly.
The automatic obstacle recognition with
reversing function is only an aid. It is not a
substitute for your attentiveness when open- ing and closing the tailgate. 104
Luggage compartmentOpening and closing

G
WARNING
The reversing function does not react:
R to soft, light and thin objects, e.g. small fin-
gers
R over the last 8 mm of the closing path
This means that the reversing feature cannot
prevent someone being trapped in these sit-
uations. There is a risk of injury.
When closing make sure that no body parts
are in the closing area.
If someone is trapped:
R press the Fbutton on the key or
R pull or press the remote operating switch
on the driver's door or
R press the closing or locking button on the
tailgate or
R pull the handle on the tailgate
Vehicles with HANDS-FREE ACCESS: it is
also possible to stop the closing process by
performing a kicking movement under the
rear bumper. Opening/closing from the outside
Opening X
Press the Fbutton on the key.
or X Pull handle :.
The tailgate opens. Closing
X
Pull the tailgate down using recesses :
and push it closed.
X Lock the vehicle if necessary with the &
button on the key or with KEYLESS-GO
(Y page 95). Opening/closing automatically from
the outside
Important safety notes G
WARNING
Parts of the body could become trapped dur-
ing automatic closing of the tailgate. More-
over, people, e.g. children, may be standing in the closing area or may enter the closing area
during the closing process. There is a risk of
injury.
Make sure that nobody is in the vicinity of the closing area during the closing process.
Use one of the following options to stop the
closing process:
R press the Fbutton on the key
R pull or press the remote operating switch
on the driver's door
R press the closing or locking button on the
tailgate
R pull the handle on the tailgate
Vehicles with HANDS-FREE ACCESS: it is
also possible to stop the closing process by
performing a kicking movement under the
rear bumper. Luggage compartment
105Opening and closing Z