Driving and operating125
Immediately after motorway driving
an Autostop may be inhibited.
New vehicle running-in 3 122.
Battery discharge protection
To ensure reliable engine restarts, several battery discharge protection
features are implemented as part of
the stop-start system.
Power saving measures
During an Autostop, several electrical
features such as auxiliary electric
heater or rear window heating are
disabled or switched into a power
saving mode. The fan speed of the
climate control system is reduced to
save power.
Restart of the engine by the
driver Depress the clutch pedal to restart the
engine.
The engine start is indicated by the
needle at the idle speed position in
the tachometer.If the selector lever is shifted out of
neutral before depressing the clutch
first, control indicator - illuminates
or is shown as a message in the Driver Information Centre.
Control indicator - 3 85.
Restart of the engine by the
stop-start system
The selector lever has to be in neutral to enable an automatic restart.
If one of the following conditions occurs during an Autostop, the
engine will be restarted automatically
by the stop-start system:
■ The stop-start system is manually deactivated
■ the bonnet is opened
■ the driver's seat belt is unfastened and the driver's door is opened
■ the engine temperature is too low
■ the battery is discharged
■ the brake vacuum is not sufficient
■ the vehicle starts to move■ the climate control system requests
an engine start
■ the air conditioning is manually switched on
If the bonnet is not fully closed, a
warning message is displayed in the
Driver Information Centre.
If an electrical accessory, e.g. a
portable CD player, is connected to
the power outlet, a brief power drop during engine restart might be
noticeable.
Parking ■ Do not park the vehicle on an easily
ignitable surface. The high
temperature of the exhaust system
could ignite the surface.
■ Always apply parking brake without
pressing release button. Apply as
firmly as possible on downhill or
uphill slopes. Depress the foot
brake at the same time to reduce
operating force.
■ Switch off the engine and ignition. Turn the steering wheel until the
steering wheel lock engages.
132Driving and operating
The deactivation of the AWD system
will be indicated by a message on the
Driver Information Centre.
If a service message or warning
code S73 is displayed on the Driver Information Centre, there is a
malfunction in the AWD system. Seek the assistance of a workshop.
Vehicle messages 3 94, Towing the
vehicle 3 187.Brakes
The brake system comprises two
independent brake circuits.
If a brake circuit fails, the vehicle can
still be braked using the other brake
circuit. However, braking effect is
achieved only when the brake pedal
is depressed firmly. Considerably
more force is needed for this. The braking distance is extended. Seek
the assistance of a workshop before
continuing your journey.
When the engine is not running, the
support of the brake servo unit
disappears once the brake pedal has been depressed once or twice.
Braking effect is not reduced, but
braking requires significantly greater
force. It is especially important to bear this in mind when being towed.
Control indicator R 3 85.
Antilock brake system Antilock brake system (ABS)
prevents the wheels from locking.ABS starts to regulate brake pressure
as soon as a wheel shows a tendency to lock. The vehicle remains
steerable, even during hard braking.
ABS control is made apparent
through a pulse in the brake pedal
and the noise of the regulation
process.
For optimum braking, keep the brake
pedal fully depressed throughout the
braking process, despite the fact that
the pedal is pulsating. Do not reduce
the pressure on the pedal.
After starting off the system performs a self-test which may be audible.
Control indicator u 3 86.
Adaptive brake light
During full braking, all three brake
lights flash for the duration of ABS
control.
Driving and operating133
Fault9Warning
If there is a fault in the ABS, the
wheels may be liable to lock due
to braking that is heavier than
normal. The advantages of ABS are no longer available. During
hard braking, the vehicle can no longer be steered and may
swerve.
Have the cause of the fault remedied
by a workshop.
Parking brake
Always apply parking brake firmly
without operating the release button,
and apply as firmly as possible on a
downhill or uphill slope.
To release the parking brake, pull the lever up slightly, press the release
button and fully lower the lever.
To reduce the operating forces of the
parking brake, depress the foot brake
at the same time.
Control indicator R 3 85.
Brake assist
If the brake pedal is depressed
quickly and forcefully, maximum
brake force is automatically applied
(full braking).
Maintain steady pressure on the
brake pedal for as long as full braking
is required. Maximum brake force is
automatically reduced when the
brake pedal is released.
Hill start assist
The system helps prevent unintended movement when driving away on
inclines.
When releasing the foot brake after
stopping on an incline, the brakes
remain on for a further two seconds.
The brakes release automatically as
soon as the vehicle begins to
accelerate.
The hill start assist is not active during
an Autostop.
134Driving and operatingRide control systems
Traction Control system
The Traction Control system (TC) is a
component of the Electronic Stability
Control (ESC) 3 134.
TC improves driving stability when necessary, regardless of the type of
road surface or tyre grip, by
preventing the drive wheels from
spinning.
As soon as the drive wheels starts to spin, engine output is reduced and
the wheel spinning the most is braked individually. This considerably
improves the driving stability of the
vehicle on slippery road surfaces.
TC is operational after each engine
start as soon as the control indicator
b extinguishes.
When TC operates b flashes.9 Warning
Do not let this special safety
feature tempt you into taking risks
when driving.
Adapt speed to the road
conditions.
Control indicator b 3 87.
Deactivation
TC can be switched off when spinning of drive wheels is required:
press button t briefly to deactivate
TC, k illuminates. Deactivation is
displayed as status message in the
Driver Information Centre.
TC is reactivated by pressing the t
button again.
TC is also reactivated the next time
the ignition is switched on.
Electronic Stability Control Electronic Stability Control (ESC)
improves driving stability when
necessary, regardless of the type of
road surface or tyre grip. It also
prevents the drive wheels from
spinning.
As soon as the vehicle starts to
swerve (understeer/oversteer),
engine output is reduced and the wheels are braked individually. This
considerably improves the driving
stability of the vehicle on slippery road
surfaces.
ESC is operational after each engine
start as soon as the control indicator b extinguishes.
When ESC operates b flashes.
Driving and operating1359Warning
Do not let this special safety
feature tempt you into taking risks
when driving.
Adapt speed to the road
conditions.
Control indicator b 3 87.
Deactivation
For very high-performance driving
ESC can be deactivated: hold button
t depressed for approx. 5 seconds.
Control indicator k and n illuminate.
ESC is reactivated by pressing the t
button again. If the TC system was
previously disabled, both TC and
ESC are reactivated.
ESC is also reactivated the next time
the ignition is switched on.
Descent control system The Descent control system (DCS)
allows the vehicle to travel at a low
speed without depressing the foot
brake. The vehicle will automatically
decelerate to a low speed and remain
at that speed when the system is
activated. Some noise or vibration
from the brake system may be
apparent when the system is active.Caution
Use only when descending steep
grades while driving off-road. Do
not use when driving on normal
road surfaces. Unnecessary
usage of the DCS function, such
as while driving on normal roads,
may damage the brake system
and the ESC function.
Switching on
At speeds below approx. 40 km/h,
press button u. DCS is operational as
soon as control indicator u
illuminates.
Activation
DCS is active at speeds between 2 and 35 km/h. Depending on the
current speed, the vehicle will be
136Driving and operating
accelerated or decelerated to a speed
between 5 and 20 km/h. When DCS
is active, u flashes.
DCS will only be activated on roads with a certain incline.
Deactivation
DCS is deactivated if the vehicle is
decelerated below 2 km/h or
accelerated above 35 km/h.
Switching off
Press button u again. Control
indicator u extinguishes.
At speeds above 60 km/h the system
is switched off automatically.Driver assistance
systems9 Warning
Driver assistance systems are
developed to support the driver
and not to replace the driver's
attention.
The driver accepts full
responsibility when driving the
vehicle.
When using driver assistance
systems, always take care
regarding the current traffic
situation.
Cruise control
The Cruise control can store and
maintain speeds of approx. 30 to
200 km/h. Deviations from the stored
speeds may occur when driving uphill or downhill.
It is the responsibility of the driver to
comply with local posted speed limits.
For safety reasons the cruise control
cannot be activated until the foot
brake has been operated once.
Activating in first gear is not possible.
Do not use the cruise control if it is not advisable to maintain a constant
speed.
With automatic transmission, only
activate cruise control in automatic
mode.
Control indicator m 3 89.
Switching on
Press button m: control indicator m in
instrument cluster illuminates white.
Driving and operating139
By pressing button m to activate
cruise control or adaptive cruise
control or by switching off the ignition,
speed limiter is also deactivated and
the stored speed is deleted.
Forward collision alert The forward collision alert can help to
avoid or reduce the damage caused
by front-end crashes. If a vehicle directly ahead is approached too
quickly, a warning chime and alert in
the Driver Information Centre is
provided.The green illuminated vehicle ahead
symbol A appears in the
speedometer when the system has
detected a vehicle in the driving path. A precondition is that forward collision
alert is activated in the vehicle
personalisation menu 3 99 or that it is
not deactivated with button V
(depending on the system, see
following).
Forward collision alert based on
front camera system Forward collision alert uses the front
camera system in the windscreen to
detect a vehicle directly ahead, in
your path, within a distance of approx.
60 metres.
Activation
Forward collision alert operates
automatically above 40 km/h, if it is not deactivated with button V, see
below.
Selecting the alert sensitivity
The alert sensitivity can be set to
near, medium or far.
Press button V: the current setting is
shown on the Driver Information
Centre. Press button V again to
change the alert sensitivity.
140Driving and operating
Alerting the driver
When approaching another vehicle
too rapidly, the collision alert warning page will be indicated in the Driver
Information Centre. Simultaneously a
warning chime sounds. Depress the
brake pedal, if it is required by the situation.
Deactivation
The system can be deactivated.
Press button V repeatedly until the
following message appears in the
Driver Information Centre.
General information
9 Warning
Forward collision alert is just a
warning system and does not
apply the brakes. When
approaching a vehicle ahead too
rapidly, it may not provide you
enough time to avoid a collision.
The driver accepts full
responsibility for the appropriate
following distance based on traffic,
weather and visibility conditions.
The complete attention of the
driver is always required while
driving. The driver must always be
ready to take action and apply the
brakes.
System limitations
The system is designed to warn only for vehicles, but may react also to
other metallic objects.
In the following cases, forward
collision alert may not detect a vehicle ahead or sensor performance is
limited:
■ on winding roads,
■ when weather limits visibility, e.g. fog, rain, or snow,
■ when the sensor is blocked by snow, ice, slush, mud, dirt, or
windscreen damage.