152Driving and operatingStop-start systemThe stop-start system helps to save
fuel and to reduce the exhaust
emissions. When conditions allow, it
switches off the engine as soon as the
vehicle is at a low speed or at a
standstill, e.g. at a traffic light or in a
traffic jam. It starts the engine
automatically as soon as the clutch is depressed. A battery sensor ensures
that an Autostop is only performed if
the vehicle battery is sufficiently
charged for a restart.
Activation
The stop-start system is available as
soon as the engine is started, the
vehicle starts-off and the conditions
as stated below in this section are
fulfilled.Deactivation
Deactivate the stop-start system
manually by pressing the eco button.
The deactivation is indicated when
the LED in the button extinguishes.
Autostop
If the vehicle is at a low speed or at a
standstill, activate an Autostop as
follows:
■ Depress the clutch pedal
■ set the lever to neutral
■ release the clutch pedal
The engine will be switched off while
the ignition stays on.
An Autostop is indicated by the
needle at the AUTOSTOP position in
the tachometer. On some versions a
control indicator in the instrument
cluster lights up when engine is in Autostop.
During an Autostop, the heating and
brake performance will be
maintained.
Driving and operating161
2. Insert the special tool into theopening below the ignition switch
as far as it will go and swivel it
slightly.
3. Turn special tool to the front and remove key from the ignition
switch. Several attempts may be
required to successfully remove
the key.
Manual transmission
To engage reverse, with the vehicle
stationary press the release button on the selector lever and engage the
gear.
If the gear does not engage, set the
lever to neutral, release the clutch
pedal and depress again; then repeat
gear selection.
Do not grind the clutch unnecessarily. When operating, depress the clutchpedal completely. Do not use the
pedal as a foot rest.
Caution
It is not advisable to drive with the hand resting on the selector lever.
162Driving and operatingDrive systems
All-wheel drive The All-wheel drive system enhances
driving characteristics and stability,
and helps to achieve the best
possible driveability regardless of
ground surface. The system is always
active and cannot be deactivated.
The torque is distributed steplessly
between the wheels of the front and
rear axle, depending on the driving
conditions. Additionally the torque
between the rear wheels is distributed
depending on the surface.
For optimum system performance,
the vehicle's tyres should not have
varying degrees of wear.
If a service message is displayed in
the Driver Information Centre, the
system may have limited functionality (or be completely disabled in some
cases, i.e. the vehicle switches to
Front-wheel drive). Seek the
assistance of a workshop.
Towing the vehicle 3 253.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 3 101.
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 3 102.
Adaptive brake light During full braking, all three brakelights flash for the duration of ABS
control.
Driving and operating163
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
Manual 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 3 101.
Electric parking brake
Applying when vehicle is stationary
Pull switch m for approx.
one second, the electric parking
brake operates automatically with an adequate force. For maximum force,
e.g. parking with trailer or on inclines,
pull switch m twice.
The electric parking brake is applied
when control indicator m lights up
3 101.
The electric parking brake can always
be activated, even if the ignition is off.
Driving and operating173
vehicle speed increases or decreasesto follow the vehicle in front, but willnot exceed the set speed. It may
apply limited braking with activated
brake lights.
The adaptive cruise control can store
and maintain speeds over approx.
15 mph and brakes automatically to
follow a slower vehicle driving ahead
to a minimum speed of 9 mph. On vehicles with automatic transmission
the system brakes to a stop.
Adaptive cruise control uses a radar
sensor to detect the vehicles ahead.
If no vehicle is detected in the driving path, the adaptive cruise control will
behave like a traditional cruise
control.
For safety reasons, the system
cannot be activated before the brake
pedal has been depressed once
since switching on ignition. Activation
in first gear is not possible.
Adaptive cruise control is mainly
advised to be used on long straight
roads like highways or country roads
with steady traffic. Do not use the
system if it is not advisable to
maintain a constant speed.
Control indicator A 3 105, m 3 105,
C 3 105.9 Warning
The complete driver attention is
always required while driving with adaptive cruise control. The driver stays fully in control of the vehicle
because the brake pedal, the
accelerator pedal and the cancel
switch have priority over any
adaptive cruise control operation.
Switching on
Press button C to switch on adaptive
cruise control. The control indicator
m or C in the instrument cluster
illuminates white.
Activation by setting the speed Adaptive cruise control can be
activated between 15 mph and
112 mph.
Accelerate to the desired speed and
turn thumb wheel to SET/-, the
current speed is stored and
178Driving and operating
Driver's attention■ Use adaptive cruise control carefully on bends or mountain
roads, as it can lose the vehicle
ahead and need time to detect it
again.
■ Do not use the system on slippery roads as it can create rapid
changes in tyre traction (wheel spinning), so that you could lose
control of the vehicle.
■ Do not use adaptive cruise control during rain, snow or heavy dirt, as
the radar sensor can be covered by a water film, dust, ice or snow. This
reduces or suppresses completely
the visibility. In case of sensor
blockage, clean the sensor cover.
System limits ■ The system's automatic brake force
does not permit hard braking and
the braking level may not be
sufficient to avoid a collision.
■ After a sudden lane change, the system needs a certain time to
detect the next preceding vehicle.So if a new vehicle is detected, the
system may accelerate instead of
braking.
■ Adaptive cruise control does ignore
the oncoming traffic.
■ Adaptive cruise control does not brake for pedestrians, animals or
stopped vehicles.
Bends
The adaptive cruise control calculates
a predicted path based on the
centrifugal force. This predicted path
considers the current bend
characteristic, but cannot consider a
future bend change. The system may lose the current vehicle ahead or
consider a vehicle which is not in the
actual lane. This can happen when
entering or exiting a bend or if the
bend gets stronger or weaker. If it no
longer detects any vehicle ahead,
then control indicator A will
extinguish.
If the centrifugal force is too high in a bend, the system slows down the vehicle slightly. This braking level is
not designed to avoid spinning-off the
bend. The driver is responsible for
reducing the selected speed before
entering a bend and in general to
adapt the speed to the road type and
to existing speed limits.
Motorways
On motorways, adapt the set speed
to the situation and the weather.
Always consider that adaptive cruise
control has a limited visibility range, a
limited braking level and a certain
reaction time to verify if a vehicle is on
the driving path or not. Adaptive
cruise control may not be able to
184Driving and operating
If there is no vehicle ahead or the
vehicle ahead is out of range, two
dashes will be displayed: -.- s.
If Adaptive cruise control is active,
this page shows the following
distance setting instead 3 172.
Active Emergency Braking Active emergency braking can help to reduce the damage from crashes with vehicles and obstacles directly
ahead, when a collision can no longer
be avoided either by manual braking
or by steering. Before the active
emergency braking applies, the driver is warned by the forward collision
alert 3 180.
The feature uses various inputs (e.g.
radar sensor, brake pressure, vehicle speed) to calculate the probability of
a frontal collision.
Active emergency braking operates automatically above walking speed, provided that Auto Collision
Preparation setting is not deactivated
in the vehicle personalisation menu
3 117.The system includes:
■ Brake preparation system
■ Emergency automatic braking
■ Forward looking brake assist9 Warning
This system is not intended to
replace the driver responsibility for driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver must continue to apply the brake
pedal as the driving situation
dictates.
Brake preparation system
When approaching a vehicle ahead
so quickly that a collision is likely, the brake preparation system slightly
pressurises the brakes. This reduces
the response time, when a manual or automatic braking is requested.
The brake system is prepared so that braking can occur more rapidly.
Emergency automatic braking
After the brake preparation and just
before the imminent collision, this
function automatically applies limited
braking to reduce the impact speed of
the collision.
Forward looking brake assist
In addition to the brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. Therefore,
depressing the brake pedal slightly
results in immediate hard braking.
This function helps the driver brake
quicker and harder before the
imminent collision.9 Warning
Active emergency braking is not
designed to apply hard
autonomous braking or to
automatically avoid a collision. It is designed to reduce the vehicle
speed before a collision. It may not
react for stopped vehicles,
Driving and operating193
Detection zones
The system sensors cover a zone of
approx. 3.5 metres parallel on both
vehicle sides and approx. 3 metres
rearwards on side blind zone alert
(A) and approx. 70 metres rearwards
on lane change alert (B) on parallel
lanes. The zones start at each
exterior mirror. The height of the zone
is approx. between 0.5 metres and
2 metres off the ground.
Deactivation
Activation or deactivation of the lane
change alert can be set in the vehicle personalisation menu in the Colour-
Info-Display.
Select the relevant setting in Settings,
I Vehicle in the Colour-Info-Display.
Colour-Info-Display 3 113.
Vehicle personalisation 3 117.
The system is deactivated if the
vehicle is towing a trailer.
Deactivation is indicated by a
message in the Driver Information
Centre (DIC).
Notice
After use, the system requires a calibration. For optimal
performance, drive as soon as
possible on a straight highway road
with roadside objects, e.g. guardrails
and barriers for some distance.
Fault Occasional missed alerts can occur
under normal circumstances and will
increase in wet conditions or in sharp
curves. Otherwise the system maylight up due to guardrails, signs, trees,
shrubs or other immobile objects.
This is normal operation and the
system does not need to be serviced.
Lane change alert may not operate
when the left or right corners of the
rear bumper are covered with mud,
dirt, snow, ice, slush, or in heavy
rainstorms. Cleaning instructions
3 257.
In the event of a fault in the system or if the system does not work due to
temporary conditions, a message is
displayed in the Driver Information
Centre (DIC). Seek the assistance of
a workshop.
Rear view camera
The rear view camera assists the
driver when reversing, by displaying a view of the area behind the vehicle.
The view of the camera is displayed
in the Colour-Info-Display.