Driving and operating173Brakes
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 3 111.
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 3 112.
Adaptive brake light
During full braking, all three brake
lights flash for the duration of ABS
control.Fault9 Warning
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.
174Driving and operatingParking brake
Manual parking brake9 Warning
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 3 111.
Electric parking brake
Applying when vehicle is stationary
9 Warning
Pull switch m for approx.
one second, the electric parking
brake operates automatically with
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
illuminates 3 112.
The electric parking brake can always
be activated, even if the ignition is off.
Do not operate electric parking brake
system too often with engine not
running, as this will discharge the
vehicle battery.
Before leaving the vehicle, check the electric parking brake status. Control
indicator m 3 112.
Releasing
Switch on ignition. Keep brake pedal
depressed and then press switch m.
Drive away function
Vehicles with manual transmission:
Depressing the clutch pedal and then
slightly releasing the clutch pedal and
slightly depressing the accelerator
pedal releases the electric parking
182Driving and operatingBy pressing 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.
Adaptive cruise control Adaptive cruise control is an
enhancement to traditional cruise
control with the additional feature of
maintaining a certain distance behind
the vehicle ahead.
Adaptive cruise control automatically
decelerates the vehicle when
approaching a slower moving vehicle. It then adjusts the vehicle speed to
follow the vehicle ahead at the
selected following distance. The
vehicle speed increases or decreases to 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.
30 mph and brakes automatically to
follow a slower vehicle driving ahead
down to a minimum speed of
18 mph.
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 after
switching on ignition. Activation in first gear is not possible.
Adaptive cruise control is mainly
advised to be used on long straight
roads, e.g. 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 3 116, m 3 116.
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 C to switch on adaptive cruise
control. The control indicator m
illuminates white.
Driving and operating187entering 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 in
the driving path or not. Adaptive
cruise control may not be able to
brake the vehicle in time to avoid a
collision with a much slower vehicle or after a lane change. This is
particularly true if driving fast or if the
visibility is reduced due to weather
conditions.
While entering or exiting a motorway,
adaptive cruise control may lose the
vehicle ahead and accelerate up to
the set speed. For this reason,
decrease the set speed before the
exit or before the entry.
Vehicle path changes
If another vehicle enters your driving
path, adaptive cruise control will first
consider the vehicle when it is
completely in your path. Be ready to
take action and depress the brake
pedal, if you need to brake more
quickly.
Hill and trailer considerations
System performance on hills and
when towing a trailer depends on
vehicle speed, vehicle load, traffic
conditions and the road gradient. It
may not detect a vehicle in your path
while driving on hills. On steep hills,
you may have to use the accelerator
pedal to maintain your vehicle speed.
When going downhill, especially
when towing a trailer, you may have
to brake to maintain or reduce your
speed.
Note that applying the brake
deactivates the system. It is not
recommended to use adaptive cruise
control on steep hills especially when towing a trailer.
Driving and operating193The 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
3 129.
The system includes: ● brake preparation system
● emergency automatic braking
● forward looking brake assist9Warning
This system is not intended to
replace the driver responsibility of driving the vehicle and looking
ahead. Its function is limited to
supplemental use only. The driver shall 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 brake preparation
system and emergency automatic
braking, the forward looking brake
assist function makes the brake assist more sensitive. In this way,
depressing the brake pedal slightly
results immediately in a strong
braking. This function helps the driver
brake quicker and stronger before the imminent collision.9 Warning
Active emergency braking is not
designed to apply strong
autonomous braking or to avoid automatically a collision. It is
designed to reduce the vehicle
speed before collision. It may not
react on stopped vehicles,
pedestrians or animals. After a
sudden lane change, the system
needs a certain time to detect the
next preceding vehicle.
The complete attention of the
driver is always required while
driving. The driver shall always be ready to take action and apply the brakes and steer to avoid
collisions. The system is designed
to work with all occupants wearing their seat belts.
System limitations
The active emergency braking has
limited or no function during rain,
snow or heavy dirt, as the radar
sensor can be covered by a water
202Driving and operating
Side blind spot alert is active from
speeds of 6 mph up to 87 mph.
Driving faster than 87 mph
deactivates the system, indicated by
low lighting warning symbols B in
both exterior mirrors. Reducing the speed again will extinguish the
warning symbols. If a vehicle is then
detected in the blind zone, the
warning symbols B will illuminate as
normal on the relevant side.
When the vehicle is started, both exterior mirror displays will briefly
come on to indicate that the system is operating.
The system can be activated or
deactivated in the menu Settings in
the Info-Display, vehicle
personalisation 3 129.
Deactivation is indicated by a
message in the Driver Information
Centre.
Detection zones The system sensor covers a zone of
approx. three metres on both sides of
the vehicle. This zone starts at each
exterior mirror and extends rearwards by approx. three metres. The height
of the zone is approx. between
0.5 metres and two metres off the
ground.
The system is deactivated if the
vehicle is towing a trailer.
Side blind spot alert is designed to ignore stationary objects such as
guardrails, posts, curbs, walls and
beams. Parked vehicles or oncoming
vehicles are not detected.Fault
Occasional missed alerts can occur
under normal circumstances and will
increase in wet conditions.
Side blind spot alert does 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
3 265.
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. Seek the assistance of a
workshop in case of a permanent
fault.
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.
204Driving and operatingThe function can be deactivated in the
Settings menu in the Info-Display.
Vehicle personalisation 3 129.
Warning symbols
Warning symbols are indicated as
triangles 9 on the picture which
shows obstacles detected by the rear sensors of the advanced parking
assist.
Display settings
Navi 650 /Navi 950 : Brightness can be
set with the up/down buttons of the
multifunction knob.
CD 600 : Brightness can be set by first
pressing and then turning the
multifunction knob.
Deactivation The camera is deactivated when a
certain forward speed is exceeded or
if reverse gear is not engaged for
approx. ten seconds.
Activation or deactivation of the rear
view camera can be changed in the Settings menu in the Info-Display.
Vehicle personalisation 3 129.
Fault
Fault messages are displayed with a
9 on the top line of the Info-Display.
The rear view camera may not
operate properly when:
● The surrounding area is dark.
● The sun or the beam of headlights is shining directly into
the camera lens.
● Ice, snow, mud, or anything else covers the camera lens. Clean
the lens, rinse it with water, and
wipe it with a soft cloth.● The tailgate is not closed correctly.
● The vehicle had a rear-end accident.
● There are extreme temperature changes.
Traffic sign assistant
Functionality
The traffic sign assistant system
detects designated traffic signs via a
front camera and displays them in the Driver Information Centre.
Driving and operating205Traffic signs which will be detected
are:Limit and no passing signs ● speed limit
● no passing
● end of speed limit
● end of no passingRoad signs
beginning and end of:
● motorways
● A-roads
● play streetsAdd-on signs ● additional hints to traffic signs
● restriction of trailer towing
● wet warning
● ice warning
● direction arrows
Speed limit signs are displayed in the
Driver Information Centre until the
next speed limit sign or end of speed
limit is detected or up to a defined sign
timeout.
Combinations of multiple signs in the
display are possible.
An exclamation mark in a frame
indicates that there is an additional
sign detected which is not recognised
by the system.
The system is active up to a speed of 124 mph depending on the lighting
conditions. At night the system is
active up to a speed of 99 mph.
As soon as vehicle speed becomes
slower than 34 mph the display will be
reset and the content of the traffic sign
page will be cleared, e.g. when
entering a city zone. The next
recognized speed indication will be
displayed.
Display indication