Page 209 of 324

Driver assistance systems
WARNING
Driving at high speed on icy, slippery wet
grou nd c
an result in loss of vehicle control
and serious injury to the driver and passen-
gers.
● Adjust your speed and driving style to visi-
bility
, road, traffic and weather conditions.
Even though the brake assist systems, ABS,
BAS, EDL, ASR and ESC, provide more securi-
ty, do not take unnecessary risks while driv-
ing.
● Brake assist systems can not overcome the
law
s of physics. Even with ESC and other sys-
tems, slippery and wet roads will always be
dangerous.
● Driving to quickly on wet ground can result
in the wheels lo
sing contact with the ground
in an effect known as “aquaplaning”. Without
adherence, it is impossible to brake, steer or
control the vehicle.
● Brake assist systems cannot avoid acci-
dents if
, for example, the driver does not re-
spect safety distances or drives to quickly in
difficult conditions.
● Even though brake assist systems are ex-
tremely eff
ective and help control the vehicle
in difficult situations, remember that the ve-
hicle stability depends on tyre grip.
● When accelerating on a slippery surface,
for ex
ample on ice or snow, press the acceler-
ator carefully. The wheels can still slip even
with brake assist systems resulting in loss of
vehicle control. WARNING
The effectiveness of the ESC can be consider-
ably r
educed if other components and sys-
tems affecting driving dynamics are not main-
tained or are not functioning correctly. This
includes, among others, brakes, tyres and
other systems already mentioned.
● Remember that changing and fitting other
components
to the vehicle can affect opera-
tion of the ABS, BAS, ASL EDL and ESC.
● Changes to the vehicle suspension or using
unap
proved wheel/tyre combinations can af-
fect operation of the ABS, BAS, ASL EDL and
ESC, as well as their effectiveness.
● Likewise, the effectiveness of ESC depends
on the use of s
uitable tyres ››› page 288. Note
● To en s
ure that the ESC and ASR work prop-
erly, all four wheels must be fitted with iden-
tical tyres. Any differences in the rolling radi-
us of the tyres can cause the system to re-
duce engine power when this is not desired.
● If a malfunction should occur in the ABS,
the ESC, EDL and ASR w
ill also be out of ac-
tion.
● Noises may be heard while any of the
above sy
stems are operating. Switching ASR on and off
Fig. 206
Detailed view of the centre console:
b utt
on u
sed to switch ASR on and off (vehi-
cles with ESC) The electronic stability control ESC consists
of
ABS, EDL
and ASR and on
ly works when
the engine is running.
The ASR can be switched off while the engine
is running by pressing the OFF
› ›
› Fig. 206
b
utton. The ASR (and similar) is only switch-
ed off when the required traction is not ob-
tained:
● When driving through deep snow or on
loose grou
nd (gravel, etc.).
● When “freeing” a trapped vehicle.
Turn the ASR bac
k on by pressing the but-
ton OFF
›
› ›
Fig. 206
.
207
Technical data
Advice
Operation
Emergencies
Safety
Page 210 of 324

Operation
Start assist systems Intr oduction WARNING
The intelligent technology in the start assist
sys t
ems cannot change the laws of physics.
The improved comfort provided by start as-
sist systems should not prompt you to take
risks.
● Unintentional movements of the vehicle
coul
d cause serious injury.
● The start assist systems are not a replace-
ment for driv
er awareness.
● Always try to adapt the speed of the vehi-
cle and
your style of driving to the condition
of the ground or the road and to weather and
traffic conditions.
● The start assist system cannot keep the ve-
hicle s
tationary in all conditions on a gradi-
ent or cause it to brake on steep downhill
gradients, e.g. if the road is slippery or icy. Auto Hold function*
Fig. 207
Detailed view of the centre console:
Aut o Ho
l
d button The control lamp on the button switches on
when the Aut
o Ho
l
d function is on.
When the Auto Hold function is on, this helps
the driver if they must regularly stop the vehi-
cle or if they must stop with the engine run-
ning for prolonged periods, for example, on
hills, before a traffic light or in traffic jams
with continuous stopping and starting.
The Auto Hold function automatically pre-
vents the vehicle from rolling away acciden-
tally when at a standstill, without the driver
having to keep his/her foot on the brake ped-
al.
When the system that detects that the vehi-
cle has stopped, the Auto Hold keeps the ve-
hicle at a standstill. The brake pedal can be
released. If the driver presses the brake pedal briefly or
the accel
erator to start off, the Auto Hold
function releases the brake once more. The
vehicle moves according to the gradient.
If any of the conditions necessary for the Au-
to Hold function change while the vehicle
stopped, the system is turned off as is the in-
dicator on the button ››› Fig. 207. The elec-
tronic parking brake engages where necessa-
ry to park the vehicle safely ››› .
C ondition
s
for keeping the vehicle at a
standstill with Auto Hold:
● The driver door must be closed.
● The driver seat belt must be buckled.
● The engine must be running.
● The ASR system is switched on
›››
page 189.
Automatically engaging and disengaging the
Auto Hold function
If the Auto Hold function was engaged with
the AUTO HOLD button before disengaging the
ignition, the f u
nction w
ill automatically re-
main engaged after the ignition is re-engag-
ed.
If the Auto Hold function was not disengag-
ed, it will automatically remain disengaged
after the ignition is engaged.
208
Page 211 of 324

Driver assistance systems
Permanent Auto Hold connection
The Aut o Ho
l
d function must be switched on
every time the engine is started. However, to
switch the Auto Hold function on permanent-
ly, the mark must be switched on in the Set-
tings menu, “Autohold” submenu
››› page 26.
Auto Hold works automatically under the fol-
lowing conditions:
All points must be fulfilled simultaneously
››› :
Manual gearboxAutomatic gearbox
1.If the vehicle is stopped using the brake pedal on a
flat or slope.
2.The engine must be “running smoothly”.
3.On a slope, the 1st gear
is engaged uphill or the
reverse gear is engaged
for a downhill. The
clutch must be held
down.A gear for driving is se-
lected from R, D or S.
Upon accelerating and
pressing in the clutch
simultaneously, the
brake releases gradual-
ly.Upon accelerating, the
brake releases gradual-
ly. Auto Hold turns off automatically under the
f
o
l
lowing conditions:
Manual gearboxAutomatic gearbox
1.If one of the conditions mentioned in table on
page 209 changes.
2.If the engine is “not running regularly” or if there is a malfunction.
3.When changing to idle
speed.If the selector lever is
placed in neutral (N).
4.If the engine is turned
off or stalls.If the engine is switch-
ed off.
5.If the driver accelerates
while pressing the
clutch in.If the vehicle is acceler-
ated.
6. When one of the wheels
has minimal contact
with the ground (e.g. on
uneven ground). WARNING
The Auto Hold technology is limited by the
la w
s of physics. The improved comfort provi-
ded by Auto Hold should never prompt you to
take risks.
● Never leave the vehicle running and with
the Auto Hol
d function switched on.
● Auto Hold cannot always stop the vehicle
uphill
and downhill (e.g. if the ground is slip-
pery or frozen). CAUTION
Before entering an automatic car wash, al-
wa y
s switch the Auto Hold function off, as it
could be damaged when the electronic park-
ing brake automatically engages. Start-Stop Function*
Fig. 208
Detailed view of the centre console:
St ar
t
-Stop function button With the Start-Stop system enabled, the en-
gine i
s
aut
omatically stopped when the vehi-
cle is at a standstill. The engine restarts auto-
matically when required.
The function is enabled automatically when-
ever the ignition is switched on. The instru-
ment panel displays information on the cur-
rent status. »
209
Technical data
Advice
Operation
Emergencies
Safety
Page 212 of 324

Operation
Vehicles with a manual gearbox
● When the vehicle is at a standstill, leave it
in neutr al
and t
ake your foot off the clutch.
The engine switches off.
● Simply depress the clutch pedal to move
off again.
V
ehicles with an automatic gearbox
● When the vehicle is at a standstill, depress
the brake or k
eep it pressed down. The en-
gine switches off.
● The engine will start again as soon as you
rele
ase the brake pedal.
● With the selector lever set to position P, the
engine wi
ll not start until a range of gears is
selected or the accelerator pedal is de-
pressed.
Important conditions for the engine to auto-
matically switch off
● The driver seat belt must be buckled.
● The driver door must be closed.
● The bonnet must be closed.
● The factory-fitted towing bracket must not
be electrical
ly connected to a trailer.
● A minimum engine temperature has been
reac
hed.
● The steering wheel must not be turned
more than 270 de
grees.
● The vehicle has moved since the last stop. ●
In vehic
les with Climatronic: the tempera-
ture inside the vehicle is within the pre-set
temperature range.
● The temperature set is neither very high nor
very
low.
● The air conditioning defrost function is not
switc
hed on.
● In vehicles with Climatronic: the blower has
not been manual
ly set to a high speed.
● The power level of the vehicle's battery is
sufficient
.
● The vehicle's battery temperature is neither
too high nor too lo
w.
● The vehicle is not on a steep gradient or
slope.
● The front
wheels are not overly turned.
● The heated windscreen is not switched on.
● Reverse gear is not engaged.
● The park assist system is not switched on.
Conditions
for automatically restarting the
engine
The engine may automatically restart under
the following conditions:
● If the vehicle interior is too hot or too cold.
● If the vehicle moves.
● If the vehicle's battery voltage drops. Conditions requiring the key to restart the
engine
The engine mu
st be started manually under
the following conditions:
● If the driver unbuckles his/her seat belt.
● If the driver door is opened.
● If the bonnet is opened.
● In vehicles with a manual gearbox: if a gear
has
been selected.
Switching Start-Stop mode on and off man-
ually
● Press the button on the centre console
› ›
›
Fig. 208.
● The button will light up when the Start-Stop
function i
s switched off.
The engine will start immediately if the vehi-
cle is in Stop mode when it is switched off
manually. WARNING
The brake servo and the power steering do
not w ork
when the engine is switched off.
● Never allow the vehicle to move when the
engine is
switched off. CAUTION
Using the Start-Stop function for a long peri-
od at v
ery high outside temperatures could
damage the vehicle's battery. 210
Page 213 of 324

Driver assistance systems
Note
● In some ca se
s, you may have to restart the
vehicle using the key. Observe the corre-
sponding message on the instrument panel
display.
● If the steering wheel is turned more than
270°, Stop w
ill not function; however, the an-
gle of steering wheel turn does not affect
starting the vehicle. Parking distance warning sys-
t
em*
Intr oduction The parking distance warning system assists
the driv
er when p
ark
ing. When the vehicle
approaches an obstacle, forwards or back-
wards, an intermittent audible warning will
be heard, higher or lower depending on the
distance. The shorter the distance, the short-
er the intervals between tones. If the vehicle
is too close to the obstacle, the audible warn-
ing becomes constant.
If you continue to approach an obstacle when
the sound is continuous, this means the sys-
tem can no longer measure the distance.
The sensor system on the bumpers transmit
and receive ultrasound. Using the ultrasound
signal (transmission, reflection from the ob-
stacle and reception), this system continu- ously calculates the distance between the
bumper and the ob
stacle. WARNING
The parking distance warning system and the
optica l
parking system cannot replace driver
awareness.
● The sensors have blind spots in which ob-
stac
les and people are not registered.
● Always observe the area around the vehi-
cle, a
s the sensors do not always detect
small children, animals or objects.
● The surface of certain objects and some
clothing do not
reflect the ultrasound signals
from the parking distance system. The sys-
tem cannot detect or incorrectly detects
these objects and people wearing these
types of clothes.
● External sound sources can affect the park-
ing dis
tance aid signals. In this case, under
certain circumstances, people and objects
will not be detected. CAUTION
● The sensor s
may not always be able to de-
tect objects such as trailer draw bars, thin
rails, fences, posts, trees and open boots,
etc. This could result in damage to your car.
● Although the parking distance warning sys-
tem detect
s and warns of the presence of an
obstacle, the obstacle could disappear from
the angle of measurement of the sensors if it
is too high or low and the system would no longer show it. Therefore, it will not warn you
of the
se o
bjects. Ignoring the warnings of the
parking sensor system could cause consider-
able damage to the vehicle.
● The bumper sensors may become damaged
or misa
ligned, for example, when parking.
● To ensure that the system works properly,
the bumper sensor
s must be kept clean, free
of ice and snow and uncovered.
● When cleaning the sensors with high-pres-
sure or s
team cleaning equipment, spray the
sensors briefly at a distance of no less than
10 cm (4 inches). Note
Acoustic sources may lead to erroneous warn-
ing s
on the parking sensor system, e.g.
rough tarmac, cobbles or the noise of other
vehicles. 211
Technical data
Advice
Operation
Emergencies
Safety
Page 214 of 324

Operation
Parking distance warning system* Fig. 209
Detailed view of the centre console:
b utt
on f
or switching the parking distance
warning system on and off Fig. 210
Parking sensor system sensors on
the fr ont
b
umper The parking distance warning system assists
the driv
er when p
ark
ing. If the vehicle is ap-
proaching an obstacle, an intermittent audi-
ble warning is emitted. The shorter the dis-
tance, the shorter the intervals between tones. If the vehicle is too close to the obsta-
cle, the audib
le warning becomes constant.
Switching the parking distance warning sys-
tem on and off ● Press the button
›››
Fig. 209
when the
ignition i
s switched on.
● Automatic on: select r
everse gear.
● Automatic off: drive fa
ster than 15 km/h
(9 mph).
The button lights up when the function is
switched on.
Things to note on the parking distance warn-
ing system
● The parking distance warning system
sometimes r
egisters water on the sensors as
an obstacle.
● If the distance does not change, the warn-
ing sign
al will sound less loudly after a few
seconds. If the continuous signal sounds, the
volume will remain constant.
● When the vehicle moves away from the ob-
stac
le, the beeping sound automatically
switches off. On approaching the obstacle
again, the beeping sound will automatically
switch back on.
● If the electronic parking brake is engaged
or the selector l
ever is set to P, no audible
warning will be emitted. ●
Your tec
hnical service centre can adjust the
volume of the warning signals. Note
If the parking distance warning system is
fau lty
, a constant audible warning will be
emitted the first time it is switched on and
the button will flash. Switch the parking dis-
tance warning system off using the button
and take the vehicle to a specialised work-
shop to have the system checked as soon as
possible. 212
Page 215 of 324

Driver assistance systems
Optical parking system* (OPS) Fig. 211
On-screen OPS display: A has de-
t ect
ed an o
bstacle in the collision zone; Bhas detected an obstacle in the segment;
Czone recorded behind the vehicle.
Fig. 212
On-screen OPS display: A has de-
t ect
ed an o
bstacle in the segment; B restric-
t ed ar e
a in front of the vehicle. The optical parking system is an accessory to
the P
ark
in
g distance warning system ›››
page 212 and the park assist system
››
› page 214.
The zone recorded by the sensors in front of
and behind the vehicle is displayed on the
factory-fitted radio or navigation system
screen. Any obstacles are displayed in rela-
tion to the vehicle ››› .
FunctionNecessary operations
Switching the
display on:Switch on the parking distance
warning system
››› page 212 or the
park assist system ››› page 214. The
OPS switches on automatically.
Switching the
display off man-
ually:Press a zone selection button on the
factory-fitted radio or navigation
system
OR: briefly press the function button
or RVC on the screen.
Switching the
display off man-
ually:
Drive forwards at more than about
10-15 km/h (6-9 mph).
Select the reverse gear on vehicles
with rear assist
››› page 217. The
display changes to the image of the
camera. Zones explored
The
z
one in whic
h obstacles are recognised
runs to a distance of around 120 cm from the
front of the vehicle and up to 60 cm to the
side ›››
Fig. 212 B . Behind the vehicle, the
z one an
aly
sed reaches a distance of up to
160 cm and around 60 cm to the sides
››› Fig. 211 C .Screen display
The im
ag
e di
splayed represents the super-
vised zones in several segments. As the vehi-
cle moves closer to an obstacle, the segment
moves closer to the vehicle displayed
››› Fig. 211 B and
›››
Fig. 212
A . When the
penu ltim
at
e segment is displayed, this
means that the vehicle has reached the colli-
sion zone. Stop the vehicle!
Distance from the
vehicle to the ob-
stacleAudible
warn- ing
Displayed in
colour on the
screen: colour
of the segment if an obstacleis recognised
Front: approx. 31 -120 cm
Behind: approx. 31 -
160 cmBeeping soundYellow
Approximately 0 –
30 cm in front or be-
hind a)Perma-
nent
soundRed
a) The permanent sound starts at a somewhat greater distance
on vehicles with a factory-fitted towing bracket.
With towing bracket
A specific image is displayed on the screen of
vehicles with a factory-fitted towing bracket
and an electrically connected trailer. In this
case, the distances behind the vehicle are
not indicated. »
213
Technical data
Advice
Operation
Emergencies
Safety
Page 216 of 324

Operation
Switching the parking sensor system sound
on and off
If the button on the radio or navigation
sy s
t
em screen may mute the sound of OPS
warnings. To switch the warnings back on,
press the button again briefly.
When the OPS is switched off and back on
again, muting is cancelled. Error messages
cannot be switched off. WARNING
Do not be distracted from the traffic when
lookin g at
the screen. Park Assist system* (Park As-
s
i
s
t)
Introduction The Park Assist system helps the driver to
find a s
uit
ab
le place to park, to insert the ve-
hicle into parallel and perpendicular parking
places and to leave parallel parking places.
The Park Assist system is limited to the sys-
tem abilities and requires that the driver is
especially attentive ››› .
The p ark
in
g sensor system is a component of
the Park Assist system that helps to park the
vehicle. For vehicles with the optical parking system
(OPS), the ra
dio navigation systems screen
displays the detected zones in front of and
behind the vehicle, indicating - within the
limits of the system - the position of obsta-
cles in relation to the vehicle.
The park assist system cannot be switched
on if the factory-fitted towing bracket is elec-
trically connected to a trailer. WARNING
Despite the assistance provided by the park
as s
ist system, do not run any risks when
parking. The system is not a replacement for
driver awareness.
● Unintentional movements of the vehicle
coul
d cause serious injury.
● Adjust your speed and driving style to visi-
bility
, road, traffic and weather conditions.
● The surface of certain objects and items of
clothing and e
xternal sound sources may
have a negative affect on the park assist sig-
nals or on the system sensors or may not re-
flect its signals.
● The sensors have blind spots in which ob-
stac
les and people are not registered.
● Always observe the area around the vehi-
cle, a
s the sensors do not always detect
small children, animals or objects. CAUTION
● The park a
ssist system aims exclusively at
other parked vehicles, without taking curbs
or other circumstances into account. Make
sure you do not damage the tyres and wheel
rims when parking. Where necessary, stop
manoeuvring to avoid damaging the vehicle.
● The sensors may not always be able to de-
tect o
bjects such as trailer draw bars, thin
rails, fences, posts and trees, etc. This could
result in damage to your car.
● Although the parking distance warning sys-
tem detect
s and warns of the presence of an
obstacle, the obstacle could disappear from
the angle of measurement of the sensors if it
is too high or low and the system would no
longer show it. Therefore, it will not warn you
of these objects. Ignoring the warnings of the
parking sensor system could cause consider-
able damage to the vehicle. This is also valid
when using the park assist (e.g. to park be-
hind a truck or motorcycle). Therefore, always
keep a close watch on the area in front of and
behind the vehicle while parking, and inter-
vene promptly if necessary.
● To ensure that the system works properly,
the bumper sensor
s must be kept clean, free
of ice and snow and uncovered.
● The bumper sensors may become damaged
or misa
ligned, for example, when parking.
● When cleaning the sensors with high-pres-
sure or s
team cleaning equipment, spray the
sensors briefly at a distance of no less than
10 cm. 214