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Driving
remains switched on. Make sure that the igni-
tion i
s
switched off before leaving the
vehicle, otherwise the battery could dis-
charge. Starter button*
Fig. 164
In the lower part of the centre con-
so l
e: starter button. The vehicle engine can be started with a
s
t
arter button (Press & Drive). To do so, there
must be a valid key inside the vehicle in the
area of the front or rear seats.
In vehicles with the Keyless Access
››› page 112 system, the engine can also be
started with the key in the luggage compart-
ment.
Opening the driver's door when exiting the
vehicle activates the electronic lock on the
steering column if the ignition is disabled. Switching the ignition on/off manually
Briefly p
ush the starter button without touch-
ing the brake or clutch pedal ››› .
F or
vehicles with both manual and automatic
transmission, the starter button text START ENGINE STOP flashes like a heartbeat
when the sy s
tem is preset for switching the
ignition on and off.
Automatic ignition switch-off
If the driver leaves the vehicle, taking the ve-
hicle key with them but leaving the ignition
on, the ignition is switched off automatically
after a certain time. If at that time the dipped
beam is on, the parking lights will stay on for
approx. 30 minutes. The side light can be
turned off by blocking the vehicle
››› page 112 or manually ››› page 131.
Emergency starting function
If no valid key is detected inside the vehicle,
an emergency start-up will be required. The
relevant message will appear in the dash
panel display. This may happen when, for ex-
ample, the battery of the vehicle key button
is very low or flat: ● Immediately after pushing the starter but-
ton, k
eep the vehicle key next to the right
trim of the steering column.
● The ignition connects and the engine starts
autom
atically. Emergency disconnection
If the en
gine does not switch off after briefly
pressing the starter button, an emergency
disconnect will be required:
● Press the starter button twice within 3 sec-
onds
or press it once for more than 1 sec-
ond ››› .
● The engine turns off automatically.
En gine r
estart feature
If no valid key is detected inside the vehicle
after the engine stops, you will only have 5
seconds to restart it. A warning will display
on the dash panel screen.
After this interval, it will not be possible to
start the engine without a valid key inside
the vehicle.
Automatic deactivation of the ignition on ve-
hicles with the Start-Stop system
The ignition is switched off automatically
when the vehicle is stopped and the auto-
matic engine shutdown is active, if:
● The driver's seat belt is not fastened,
● the driver does not step on any pedal,
● the driver door is opened.
Aft
er automatically turning off the ignition, if
the dipped beam is on, the side light re-
mains on for approx. 30 minutes (if the bat-
tery is sufficiently charged). If the driver locks »
167
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Operation
Emergencies
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Operation
the vehicle or manually turns off the light, the
s ide light
goes out. WARNING
Any accidental movement of the vehicle could
r e
sult in serious injury.
● When switching on the ignition, do not
pr
ess the brake or clutch pedal, otherwise
the engine could start immediately. WARNING
If vehicle keys are used negligently or with-
out due c
are, this may cause accidents and
serious injury.
● Never leave any key inside the vehicle
when ex
iting. Otherwise, a child or unauthor-
ised person could lock the vehicle, start the
engine or connect the ignition and, in this
way, operate electronic equipment (e.g. the
windows). Note
● Bef
ore leaving the vehicle, always discon-
nect the ignition manually and, if appropri-
ate, take into account the instructions on the
screen of the dash panel.
● If the vehicle is stationary for a long time
with the ignition on, the
vehicle battery
might be discharged and it might not be pos-
sible to start the engine.
● In diesel vehicles, there may be a delay in
the engine s
tarting if it requires preheating. ●
If durin
g the STOP phase you press the
START ENGINE STOP button, the ignition is
sw it
ched off and the button flashes.
● If the indication “Start-Stop system deacti-
vat
ed: Start the engine manually” is dis-
played on the dash panel display, the START ENGINE STOP button will blink.
Starting the engine
3
Valid for vehicles: with Keyless Access
StepStarting the engine with the starter but-
ton ››› page 167 (Press & Drive).
1.Press and hold the brake pedal until step 5 is
performed.
1a.In vehicles with a manual gearbox: press and
hold the clutch down until the engine starts.
2.Put the gearbox lever in neutral or the selector
lever in position P or N.
3.
Briefly press the starter button ››› Fig. 164 with-
out pressing the accelerator. For the engine to
start there must be a valid key in the vehicle.
After starting the engine, the light of the START ENGINE STOP
button changes to a fixed
light indicating that the engine has started.
4.If the engine does not start, stop and wait for
approx. 1 minute before trying again. If neces-
sary, perform an emergency start ››› page 167.
5.Disconnect the electronic parking brake when
you are about to start driving ››› page 170. WARNING
Never leave the vehicle with the engine run-
nin g, e
specially if a gear or gear range is en-
gaged. The vehicle could then suddenly move
or something strange could happen that
would cause damage, fire or serious injury. WARNING
Cold start sprays could explode or cause a
s ud
den increase in the engine speed.
● Never use sprays to cold start the engine. CAUTION
● The s t
arter motor or the engine may be
damaged if you try to start the engine while
driving or if you restart it immediately after
switching it off.
● If the engine is cold, avoid high engine
speed
s, pushing the engine too hard and rap-
id acceleration.
● Do not start the engine by pushing the ve-
hicl
e or towing it. Unburnt fuel could enter
the catalytic converter and damage it. Note
● Do not w
ait until the engine warms up with
the vehicle stationary; if you have good visi-
bility through the windows, start driving im-
mediately. This helps the engine reach oper-
ating temperature faster and reduces emis-
sions. 168
Page 171 of 328

Driving
●
Electric
al components with a high power
consumption are switched off temporarily
when the engine starts.
● When starting with a cold engine, noise
lev
els may briefly increase. This is quite nor-
mal, and no cause for concern.
● When the outside temperature is below
+5°C (+41°F), if
the engine is diesel, some
smoke may appear under the vehicle when the fuel-operated auxiliary heater is on. Stopping the engine
3
V
alid for vehicles: with Keyless Access
StepSwitch off the engine with the starter
button ››› page 167.
1.Stop the vehicle completely ››› .
2.Press and hold the brake pedal until the step
4 is performed.
3.If you are driving an automatic vehicle, place
the selector lever in position P.
4.Connect the electronic parking brake
››› page 170.
5.
Briefly press the start-up button ››› Fig. 164.
The START ENGINE STOP button blinks again. If
the engine fails to switch off, perform an emer-
gency disconnect ››› page 167.
6.If the vehicle is equipped with a manual gear-
box, put it into 1st or reverse. WARNING
Never switch off the engine while the vehicle
i s
moving. This could cause loss of control of
the vehicle, accidents and serious injury.
● The airbags and belt tensioners do not
work
when the ignition is switched off.
● The brake servo does not work with the en-
gine off.
Therefore, you need to press the
break pedal harder to brake the vehicle.
● Power steering does not work when the en-
gine is
not running. You need more strength
to steer when the engine is switched off.
● If the ignition is switched off, the steering
co
lumn could be locked, making it impossible
to control the vehicle. CAUTION
If the engine is made to work hard for a long
time, it m
ay overheat after being switched
off. To prevent damage to the engine before
switching it off, leave it idle for approx. 2 mi-
nutes in neutral. Note
After switching off the engine, the cooling fan
m a
y continue to operate in the engine com-
partment for a few more minutes, even with
the ignition off. The radiator fan is automati-
cally switched off. “My Beat” Function
For vehicles with a convenience key there is
the “M
y
Beat” function. This feature provides
an additional indication of the vehicle igni-
tion system.
When accessing the vehicle, e.g. by opening
the doors with the remote control, the START ENGINE STOP button flashes, calling at-
t ention t
o the relevant starter system button.
Upon switching the ignition on/off, the light
of the START ENGINE STOP button flashes. With
the en gine sw
itched off, after a few seconds,
the STOP ENGINE START button stops flashing
and g oe
s out.
With the engine running, the START ENGINE STOP button light stays on, indi-
c atin
g that the engine is running. Upon
switching the ignition off with the START ENGINE STOP button, it starts flashing
ag ain.
In
vehicles with the Start-Stop system , the
“My Beat” function also offers additional in-
formation:
● When the engine stops during the Stop
pha
se, the light of the START ENGINE STOP but-
t on s
tays on, since, even though the engine
is off, the Start-Stop system is active.
● When the engine cannot be stated again
with the
Start-Stop system, ›››
page 188, and
needs to be started manually, the »
169
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Operation
Emergencies
Safety
Page 172 of 328

Operation
START ENGINE STOP button flashes to indicate
thi s
fact.
Braking and parking Electr
onic parking brake Fig. 165
In the lower part of the centre con-
so l
e: electronic parking brake button. The electronic parking brake replaces the
h
andbr
ake.
Activating the electronic parking brake
The electronic parking brake can be activated
whenever the vehicle is at a standstill, even
when the ignition is switched off. Activate it
whenever you leave or park the vehicle.
● Pull and hold the ››
› Fig. 165 button.
● The parking brake is activated when the
contr
ol light of the ››› Fig. 165 button (arrow) and the red control light of the display in
the d
ash panel are on.
● Release the button.
Rel
easing the electronic parking brake
● Switch the ignition on.
● Press the button ››
› Fig. 165. At the same
time step hard on the brake pedal or, if the
engine is running, press the accelerator ped-
al slightly.
● The control light of the ››
› Fig. 165 button
(arrow) and the red control light of the dis-
play in the dash panel go out.
Automatic release of the electronic parking
brake on starting the engine
The electronic parking brake is automatically
switched off when starting if, after the driv-
er's door is closed and the driver's seat belt
fastened, any of the following situations take
place:
● On vehicles with an automatic gearbox: A
ge
ar range is engaged or the vehicle is
switched to another one and the accelerator
pedal is lightly pressed.
● In vehicles with a manual gearbox: The
clut
ch pedal is pressed fully before starting
off and the accelerator is pedal lightly press-
ed.
● To facilitate certain manoeuvres there are
ex
ceptions that allow the automatic parking brake to be released without the driver's seat
belt bein
g fastened.
The parking brake can be prevented from be-
ing automatically released by continuously
pulling up the ››› Fig. 165 switch when
starting off.
The electronic parking brake is not discon-
nected until the button is released. This
can facilitate starting off when a heavy load
is towed ››› page 255.
Automatic activation of the electronic park-
ing brake on starting the engine
In vehicles with automatic transmission, the
electronic parking brake is activated auto-
matically when exiting the vehicle incorrectly
if: ● The selector lever is in the D/S or R pos
i-
tion or in the Tiptronic selection track.
● AND: the vehicle is stationary.
● AND:
the driver door i
s open.
Emergency braking function
Only use the emergency brake function if you
are unable to stop the vehicle with the foot
brake ››› .
● Pull and hold the › ›
› Fig. 165 button in
this position to forcefully stop the vehicle. At
the same time, an acoustic warning can be
heard.
170
Page 173 of 328

Driving
● To s
top the braking process, release the
button or press the accelerator. WARNING
The improper use of the electronic parking
br ak
e can cause accidents and serious injury.
● Never use the electronic parking brake to
st
op the vehicle, unless it is an emergency.
Braking distances can be considerably lon-
ger, since, under certain circumstances, only
the rear wheels brake. Always use the foot
brake.
● Never accelerate from the engine when a
ge
ar range or a gear is engaged and the en-
gine is running. The vehicle could move, even
if the electronic parking brake is activated. CAUTION
To prevent the vehicle from unintentionally
mo v
ing when parking it, first apply the elec-
tronic parking brake and then remove your
foot from the brake pedal. Note
● In v
ehicles with a manual gearbox, releas-
ing the clutch and accelerating at the same
time automatically disconnects the electronic
parking brake.
● If the vehicle battery is flat, it will not be
pos
sible to disconnect the electronic parking
brake. Use the jump-start ›››
page 58. ●
When the el ectr
onic parking brake is ap-
plied or released, noises may be heard.
● The system performs automatic and audi-
bl
e tests sporadically in the parked vehicle if
some time elapses without the electronic
parking brake being used. Parking
The electronic parking brake should always
be ap
p
lied when the vehicle is parked.
Always note the following points when park-
ing the vehicle: – Use the brake pedal to stop the vehicle.
– Apply the electronic parking brake.
– Put it in 1st gear.
– Switch the engine off and remove the key
from the ignition.
Turn the steering wheel
slightly to engage the steering lock.
– Never leave a vehicle key in the vehicle.
Addition
al notes on parking the vehicle on
gradients:
Turn the steering wheel so that the vehicle
rolls against the kerb if it started to roll.
● If the vehicle is parked facing downhi
ll,
turn the front wheels so that they point to-
wards the kerb . ●
If the
vehicle is parked facing uphill, turn
the front wheels so that they point away from
the kerb.
● Secure the vehicle as usual by applying the
electr
onic parking brake firmly and putting it
in 1st gear. WARNING
● Tak
e measures to reduce the risk of injury
when you leave your vehicle unattended.
● Never park where the hot exhaust system
cou
ld ignite inflammable materials, such as
dry grass, low bushes, spilt fuel etc.
● Never allow vehicle occupants to remain in
the v
ehicle when it is locked. They would be
unable to open the vehicle from the inside,
and could become trapped in the vehicle in
an emergency. In the event of an emergency,
locked doors will delay assistance to vehicle
occupants.
● Never leave children alone in the vehicle.
They c
ould set the vehicle in motion, for ex-
ample, by releasing the electronic parking
brake or the gearshift lever, which would
cause the vehicle to move, but uncontrolla-
bly.
● Depending on weather conditions, it may
become e
xtremely hot or cold inside the vehi-
cle. This can be fatal. 171
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Emergencies
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Operation
Information on the brakes New brake pads
F
or the fir
st 400 km (250 miles), new brake
pads have not yet reached their maximum
braking capacity, and need to be “run in”
first. However, you can compensate for the
slightly reduced braking effect by applying
more pressure on the brake pedal. Avoid
overloading the brakes while running them
in.
Wear
The rate of wear on the brake pads depends
a great deal on how you drive and the condi-
tions in which the vehicle is operated. This is
a particular problem in urban traffic and
short stretches, or with very sporty driving.
Depending on the speed, the braking force
and the environmental conditions (for exam-
ple, the temperature, air humidity, etc.)
noises may be produced on braking.
Wet roads or road salt
In certain situations (for example, on driving
through flooded areas, in severe downpours
or after washing the vehicle) the braking ac-
tion could be delayed if the discs and pads
are damp, or frozen in winter. In this case the
brakes should be “dried” by pressing the
brake pedal several times. At high speed and with the windscreen wip-
er
s
activated, the brake pads will briefly
touch the brake discs. This takes place, al-
though unnoticeable to the driver, at regular
intervals to improve the response time of the
brakes when they are wet.
The effectiveness of the brakes can also be
temporarily reduced if the vehicle is driven
for some distance without using the brakes
when there is a lot of salt on the road in win-
ter. The layer of salt that accumulates on the
discs and pads can be removed by gently ap-
plying the brakes a few times.
Corrosion
There may be a tendency for corrosion to
form on the discs and dirt to build up on the
brake pads if the vehicle is used infrequently
or the brakes are not used very often.
If the brakes are not used frequently, or if
rust has formed on the disks, it is advisable
to clean off the pads and disks by braking
firmly a few times at a moderately high speed
››› .
F au
lt in the brake system
If the brake pedal travel should ever increase
suddenly, this may mean that one of the two
brake circuits has failed. Drive immediately
to the nearest specialised workshop and
have the fault repaired. Drive there slowly
and remember that you will have to apply more pressure on the brake pedal and allow
for lon
ger stopping distances.
Low brake fluid level
Malfunctions can occur in the brake system if
the brake fluid level is too low. The brake flu-
id level is monitored electronically.
Brake servo
The brake servo increases the pressure you
apply to the brake pedal. It works only when
the engine is running. WARNING
● Ap p
ly the brakes heavily to clean the brake
system only in a suitable traffic situation. Do
not put other road users in danger: there is
risk of causing an accident.
● Ensure the vehicle does not move while in
neutra
l, when the engine is stopped. Failure
to follow this instruction could result in an
accident.
● If the brake fluid loses its viscosity and is
sub
jected to heavy use, vapour bubbles can
form in the brake system. This reduces the ef-
ficiency of the brakes. CAUTION
● Nev er l
et the brakes “drag” by leaving your
foot on the pedal when it is not necessary to
brake. This overheats the brakes, resulting in
longer stopping distances and greater wear. 172
Page 175 of 328

Driving
●
Bef
ore driving down a long, steep gradient,
it is advisable to reduce speed and select a
lower gear. This makes use of engine braking
and relieves the brakes. If you still have to
use the brakes, it is better to brake firmly at
intervals than to apply the brakes continu-
ously. Note
● If the br
ake servo is out of action, for exam-
ple when the car is being towed, you will
have to press the brake pedal considerably
harder than normal to make up for the lack of
servo assistance.
● If you wish to equip the vehicle with acces-
sories
such as a front spoiler or wheel covers,
it is important that the flow of air to the front
wheels is not obstructed, otherwise the
brakes can overheat. Front assist system
Electronic stability control (ESC)
The E
SC
helps to improve safety. It reduces
the tendency to skid and improves the stabil-
ity and roadholding of the vehicle. The ESC
detects critical handling situations, such as
vehicle understeer or oversteer, or wheelspin
on the driving wheels. It stabilises the vehi-
cle by braking individual wheels or by reduc-
ing the engine torque. The warning lamp will flash on the instrument panel when the ESC
is
intervening .
The ESC includes the anti-lock brake system
(ABS), the front assist system (HBA), the trac-
tion control system (ASR), electronic differen-
tial lock (EDS), electronic torque control
(XDS) and tractor-trailer sway mitigation*.
ESC also helps stabilise the vehicle by chang-
ing the torque.
Anti-lock brake system (ABS)
ABS prevents the wheels from locking up un-
der braking until the vehicle has reached a
virtual standstill. You can continue to steer
the vehicle even when the brakes are on full.
Keep your foot on the brake pedal and do not
pump the brakes. You will feel the brake ped-
al pulsate while the ABS is working.
Front assist system (HBA)
The brake assist system can reduce the re-
quired braking distance. The braking force is
automatically boosted if you press the brake
pedal quickly in an emergency. You must
keep pressing the brake pedal until the dan-
ger has passed.
Traction control system (ASR)
In the event of wheelspin, the traction control
system reduces the engine torque to match
the amount of grip available. This helps the car to start moving, accelerate or climb a gra-
dient.
El
ectronic differential lock (EDL)
When the EDL detects wheelspin, it brakes
the spinning wheel and directs the power to
the other driven wheel. This function is active
up to approximately 100 km/h (62 mph).
To prevent the disc brake of the braked wheel
from overheating, the EDL cuts out automati-
cally if subjected to excessive loads. The ve-
hicle can still be driven. The EDL will switch
on again automatically when the brake has
cooled down.
Tractor-trailer sway mitigation*
If the vehicle is pulling a trailer, it will control
the following: Tractor-trailers tend to sway.
When the swaying of the trailer is felt by the
vehicle and detected by the ESC, it will auto-
matically brake the towing vehicle within the
limits of the system and mitigate the sway.
Tractor-trailer sway mitigation is not available
in all countries.
Electronic torque management (XDS)
When taking a curve, the driveshaft differen-
tial mechanism allows the outer wheel to turn
at a higher speed than the inner wheel. In
this way, the wheel that is turning faster (out-
er wheel) receives less drive torque than the
inner wheel. This may mean that in certain »
173
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Operation
situations the torque delivered to the inner
wheel i
s too high, causing the wheels to
spin. On the other hand, the outer wheel is
receiving a lower drive torque than it could
transmit. This causes an overall loss of lateral
grip on the front axle, resulting in understeer
or “lengthening” of the trajectory.
The XDS system can detect and correct this
effect via the sensors and signals of the ESC.
Via the ESC, the XDS will brake the inside
wheel and counter the excess driving torque
of that wheel. This means that the driver's
desired trajectory is much more precise.
The XDS system works in combination with
the ESC and is always active, even when ASR
traction control is disconnected, or the ESC in
Sport mode or disconnected.
Multi-collision brake
In an accident, the multi-collision brake can
help the driver by braking to avoid the risk of
skidding during the accident, which could
lead to further collisions.
The multi-collision brake works for front, side
or rear accidents, when the airbag control
unit records its activation level and the acci-
dent takes place at a speed of over 10 km/h
(6 mph). The ESC automatically brakes the
vehicle, as long as the accident has not dam-
aged the ESC, the brake hydraulics or the on-
board network The following actions control automatic brak-
ing durin
g the accident:
● When the driver presses the accelerator,
the autom
atic braking does not take place.
● When the braking pressure through press-
ing the br
ake pedal is greater than the sys-
tem’s braking pressure the vehicle will brake
automatically.
● Multi-collision braking will not be available
if E
SC is malfunctioning. WARNING
● The E SC, ABS, ASR, ED
S and the electronic
torque control system cannot exceed the lim-
its imposed by the laws of physics. Always
bear this in mind, especially on wet or slip-
pery roads. If you notice the systems cutting
in, you should reduce your speed immediate-
ly to suit the road and traffic conditions. Do
not be encouraged to take risks by the pres-
ence of more safety systems. If you do, an ac-
cident may occur.
● Please remember that the accident risk al-
wa
ys increases if you drive fast, especially in
corners or on a slippery road, or if you follow
too close behind the vehicle in front of you.
The ESC, ABS, brake assist, EDS and the elec-
tronic torque control system cannot prevent
accidents: risk of accidents!
● Accelerate with caution on slippery surfa-
ce
s (for example, icy or snow-covered). De-
spite the control systems, the driven wheels could spin, affecting the stability of the vehi-
c
l
e: risk of accident! Note
● The ABS and ASR w
ill only operate correctly
if the four wheels have identical tyres. Any
differences in the rolling radius of the tyres
can cause the system to reduce engine power
when this is not desired.
● The regulating processes of the systems
can m
ake noises when they intervene.
● If the warning lamp lights
up, or alter-
natively, there could be a fault ››› page 106. Switching on/off the ESC and ASR
The ESC is switched on automatically when
the en
gine i
s started, and only works when
the engine is running and includes the ABS,
EDS and ASR systems.
The ASR function should only be switched off
in situations in which traction is insufficient,
including:
● When driving in deep snow or on surfaces
that
are not very firm.
● To “free” the vehicle if it gets stuck.
Then swit
ch the ASR function back on.
174