2012 BMW M3 CONVERTIBLE brake

76
ControlsDriving
System limitations
Always remember that the range and abil-
ity of the system does have physical limi-
tations. It will not apply the brakes or decelerate
your vehicle when there is a slow-moving vehi-
cle, stopped vehicle, or stationary object ahead
of you, for example at a traffic light or when
approaching a parked vehicle. Also, the system
does not react to oncoming traffic, pedestrians
or other types of potentia l traffic such as a rider
on horseback. The system may also not detect
smaller moving objects such as motorcycles or
bicycles. Be especially alert when encountering
any of these situations as the system will nei-
ther automatically brake, nor provide a warning
to you. Also, be aware that every decrease in
the distance setting allows your vehicle to come
closer to a vehicle in front of you and requires a
heightened amount of alertness. <
Active Cruise Control is not and must not
be used as a collisio n avoidance/warning
system. <
If while your vehicle is actively following a vehi-
cle in front of you and the vehicle ahead speeds
up or the lane ahead becomes clear, then your
vehicle will accelerate to the speed you have
selected. Be aware that changing to a clear,
unobstructed lane will also result in your vehicle
accelerating.
Be certain to deactiva te the system when
you pull into an exit lane for a highway off-
ramp. < Also, vehicles travelin
g in a staggered manner
on a highway may cause a delay in the system's
reaction to a vehicle in front of you or may cause
the system to react to a vehicle actually in the
lane next to you. Always be ready to take action
or apply the brakes if necessary.
While Active Cruise Co ntrol is capable of
braking your vehicle automatically when
you approach a slower vehicle ahead, it is
important to be aware that the ability of the sys-
tem to apply the brakes is also limited, e.g.
when you reduce your desired speed sharply.
The system cannot stop your vehicle. It uses
only a portion of braking system capacity and
does not utilize the full ca pacity of the vehicle
braking system. Therefore, the system cannot
decrease your speed for large differences in
speed between your vehicle and the vehicle
ahead. Examples: when you approach a vehicle
traveling at a much lower speed than your own
speed such as approaching a toll booth or when
a much slower vehicle cuts in front of you at
close range. <
Active Cruise Control ca n only decelerate the
vehicle to approx. 20 mph or 30 km/h.
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Driving
Controls
Swerving vehicles
When a vehicle moves from an adjacent lane
into your lane, Active
Cruise Control will not
recognize this vehicle until it is fully in your lane
ahead of your vehicle.
When a vehicle ahead suddenly swerves
into your lane, the sy stem may not be able
to maintain the selected distance automatically.
This also applies to gr eat differences in speed
between you and vehicles ahead, e.g. when
quickly approaching a truck. There is a risk of
collision. Once the system has established that
a vehicle is indeed in fron t of you, it will indicate
that you must brake and/or maneuver the vehi-
cle yourself. Take action yourself; otherwise,
there is a risk of an accident. <
Behavior in curves
Because of the limited range of the system, it is
possible that in curves or on the peaks and val-
leys of hilly roads, a vehicle ahead may be rec-
ognized late, or not at all. Therefore, it is up to
the driver to select a speed that is prudent in
view of the curves and terrain of the roadway. In approaching a curve, it is possible that Active
Cruise Control would react briefly to a vehicle in
the adjacent lane. In a
ddition, the system can
sense if your vehicle is in a curve and may not
accelerate. If your vehicle decelerates in either
case, you can choose to overcome the deceler-
ation by briefly pressing the accelerator pedal.
Your responsibility
Your actions have priority at all times. When you
press the accelerator pedal while driving with
Active Cruise Control, the automatic braking
function will be tempor arily interrupted. Once
you release the accelerator pedal, the desired
speed or the selected distance to the vehicle
ahead is achieved again.
Do not leave your foot on the accelerator
pedal and make sure that no objects such
as floor mats are lying on the accelerator pedal.
Otherwise, the system may not be able to brake
the vehicle. <
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Controls overview
Controls
Possible displays
1
Button for selecting functions
2 Service requirements
3 Engine oil
4 Roadworthiness test 5
Front brake pads
6 Rear brake pads
7 Brake fluid
The sequence of displayed service items may
vary. The data for the ne xt service appointment
is shown first.
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ControlsTechnology for driving comfort and safety
Malfunction
The warning lamp lights up. PDC is
malfunctioning. Have the system
checked.
To avoid this problem, keep the sensors clean
and free of ice or snow in order to ensure that
they will continue to op erate effectively. When
using a high-pressure cleaner, do not spray the
sensors for extended periods of time and only
from a distance of at least 1 ft/30 cm.
Manual operation
The LED above the button also flashes.
System limitations
Even with PDC, final responsibility for
estimating the distance between the
vehicle and any obstructions always remains
with the driver. Even when sensors are pro-
vided, there is a blind sp ot in which objects can
no longer be detected. The system is also sub-
ject to the physical limits that apply to all forms
of ultrasonic measurement, such as those
encountered with traile r towbars and hitches,
thin or wedge-shaped objects, etc. Low objects
that have already been displayed, e.g. curbs,
can disappear again from the detection area of
the sensors before or af ter a continuous tone
sounds. Higher, protruding objects, e.g. ledges,
cannot be detected. Therefore, always drive
cautiously; otherwise, there is a risk of personal
injury or property damage.
Loud sound sources outside or inside the car
can drown out the PDC signal. Therefore,
always drive cautiously; otherwise, there is a
risk of personal injury or property damage. <
Driving stability control
systems
Your BMW has a number of systems that help
to maintain the vehicle's stability even in
adverse driving conditions.
ABS Antilock Brake System
ABS prevents locking of the wheels during
braking. Safe steering response is maintained
even during full braking. Active safety is thus
increased.
The ABS is operational every time you start the
engine. Braking safely, refer to page 134.
Electronic brake-force distribution
EBV
The system controls the brake pressure in the
rear wheels to ensure stable braking behavior.
Dynamic Brake Control DBC
When you apply the brakes rapidly, this system
automatically produces the maximum braking
force boost and thus helps to achieve the short-
est possible braking distance during full brak-
ing. This system exploits all of the benefits pro-
vided by ABS.
Do not reduce the pressu re on the brake for the
duration of the full braking application.
Dynamic Stability Control DSC
DSC prevents the driving wheels from losing
traction when you pull away from rest or accel-
erate. The system also recognizes unstable
driving conditions, for example if the rear of the
car is about to swerve or if momentum is acting
at an angle past the front wheels. In these
cases, DSC helps the vehicle maintain a safe
course within physical lim its by reducing engine
output and through braking actions at the indi-
vidual wheels.
The laws of physics cannot be repealed,
even with DSC. An appropriate driving
style always remains th e responsibility of the
driver. Therefore, do not reduce the additional
safety margin again by taki ng risks, as this could
result in an accident. <
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Technology for driving comfort and safety
Controls
Deactivating DSC
Press the button for at le
ast 3 seconds until the
indicator lamp for DSC OFF lights up and DSC
OFF is displayed in the instrument cluster.
Dynamic Traction Cont rol DTC and DSC have
been simultaneously de activated. Stabilizing
and drive-output promoting actions are no
longer executed.
In the same way as with a differential interlock,
even if DSC is deactivated, brake actions are
still performed to enhance drive output if the
drive wheels experience a significant loss of
traction.
To increase vehicle stability, activate DSC again
as soon as possible.
Activating DSC
Press the button again; th e indicator lamp in the
instrument cluster goes out.
For better control
If the indicator lamp flashes: the DSC
controls the driving and braking forces.
If the indicator lamp lights up: DSC and
DTC have failed.
The indicator lamp lights up and
DSC OFF is displayed in the instrument
cluster: DSC is deactivated.
Dynamic Traction Control DTC
DTC is a version of DSC in which the drive out-
put is optimized for part icular road conditions,
e.g. unplowed snow-covered roads. The sys-
tem assures the maximal drive output, but with
reduced driving stability. It is therefore neces-
sary to drive with appropriate caution.
You may find it useful to briefly activate DTC
under the following special circumstances:
> When driving uphill on snow-covered roads,
in slush or on unplowed, snow-covered
roads
> When rocking a stuck vehicle free or start-
ing off in deep snow or on loose ground
> When driving with snow chains
Activating DTC
Press the button; the indicator lamp for DSC
OFF lights up and TRACTION is displayed in
the instrument cluster.
For better control
If the indicator lamp flashes: DTC con-
trols the driving and braking forces.
If the indicator lamp lights up: DSC and
DTC have failed.
The indicator lamp lights up and
TRACTION is displayed in the instru-
ment cluster: DTC is activated.
Deactivating DTC
Press the button again; th e indicator lamp in the
instrument cluster goes out.
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ControlsTechnology for driving comfort and safety
xDrive
xDrive is your BMW's four-wheel-drive system.
The combined efforts of xDrive and DSC help to
further optimize traction and driving dynamics.
The xDrive four-wheel-drive system distributes
driving power variably to the front and rear axles
depending on the drivin g situation and road
conditions.
Hill Descent Control HDC
HDC is a downhill driving assistant that controls
your speed on steep downhill gradients and
makes it even easier to control your BMW's
handling under these conditions. The vehicle
then moves slightly faster than double walking
speed without the driver needing to intervene.
HDC can be activated as long as you are driving
under approx. 20 mph or 35 km/h. When driving
downhill at a speed of under approx. 20 mph or
35 km/h, the vehicle's speed is automatically
reduced to slightly more than double walking
speed and maintained.
Increasing or de creasing speed
By accelerating or braking you can change this
speed within a range from approx. 3 to 15 mph,
approx. 5 to 25 km/h.
You can specify a target speed within the same
range by using the lever of the cruise control.
1To increase speed
2 To decrease speed
Activating HDC
Press the button; the LED lights up.
When the vehicle is being braked automatically,
the LED flashes.
Deactivating HDC
Press the button again; the LED goes out.
HDC is automatically deactivated at speeds
greater than approx. 35 mph/60 km/h.
Using HDC
In cars with manual transmission:
Use HDC in lower gears and in reverse gear.
With automatic transmission:
You can use HDC in any drive position.
Displays in the instrument cluster
1Display for target speed
2 HDC display
Malfunction
The HDC display disappe ars during HDC oper-
ation, or does not appear:
HDC is temporarily unavailable due to exces-
sive brake temperature, or DSC has failed.
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Technology for driving comfort and safety
Controls
Drive-off assistant
The drive-off assistant enables you to drive off
smoothly on uphill gradients. It is not necessary
to use the parking brake for this.
1.
Hold the car in place by depressing the
brake.
2. Release the brake and drive off without
delay.
The drive-off assistant holds the car in
place for approx. 2 seconds after the
brake is released. Drive off without delay after
releasing the brake. Ot herwise, the drive-off
assistant will no longer hold the car in place
after approx. 2 seconds an d the car will start to
roll backwards. <
Flat Tire Monitor FTM
The concept
The system does not measure the actual infla-
tion pressure in the tires.
The system detects a pressure loss in a tire by
comparing the rotational speeds of the individ-
ual wheels while moving.
In the event of a pressure loss, the diameter and
therefore the rotational speed of the corre-
sponding wheel change. This is detected and
reported as a flat tire.
Functional requirement
The system must have be en initialized while the
tire inflation pressure was correct; otherwise,
reliable signaling of a flat tire is not ensured.
Each time a tire inflation pressure has been cor-
rected or a wheel or tire has been changed,
reinitialize the system.
System limitations
Sudden serious tire damage caused by
external influences ca nnot be indicated in
advance.<
A natural, steady pressure loss in all four tires is
not detected. Therefore, check the tire inflation
pressure regularly.
In the following situations, the system could be
delayed or malfunction:
> System has not been initialized
> Driving on snowy or slippery road surface
> Performance-oriented style of driving: slip
in the drive wheels, hi gh lateral acceleration
> Snow chains are attached
Initialization
The initialization process adopts the set infla-
tion tire pressures as reference values for the
detection of a flat tire. Initialization is started by
confirming the inflation pressures.
Do not initialize the system when driving with
snow chains.
For operating principle refer to page 82.
1. Start the engine imme diately before pulling
away, but do not drive off yet.
2. Briefly press the button 1 in the turn signal/
high beam lever up or down repeatedly until
the corresponding symbol and "RESET"
appear.
3. Press button 2 to confirm your choice of the
Flat Tire Monitor.
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ControlsTechnology for driving comfort and safety
Malfunction
The warning lamps light up. Active
steering is malfunctioning or is tem-
porarily deactivate d. At low speeds,
greater steering wheel movements
are required, whereas at higher speeds the
vehicle reacts more sensitively to steering
wheel movements. Th e stability-enhancing
feature may also be deactivated. Drive cau-
tiously and think well ahead.
Deactivation
Active steering is deacti vated to perform an ini-
tialization. A message indicates that the feature
is deactivated. Initializ ation may take several
minutes.
If the message does not disappear during the
current trip, have the system checked.
Defect
If there is a defect, a corresponding message
appears. Have the system checked.
Servotronic
The concept
The Servotronic varies the steering force
required to turn the whee ls relative to the vehi-
cle speed.
At low speeds, the steering force is strongly
assisted, i.e. less force is needed for steering.
As the vehicle speed increases, the steering
assisting power is reduced.
Malfunction
The warning lamp lights up. Ser-
votronic is malfunctioning or has
failed. Steering response will be dif-
ferent. You can continue your journey, but mod-
erate your speed and exercise due caution.
Have the system checked as soon as possible.
Brake Force Display
On the left: normal braking.
On the right: sharp braking.
Online Edition for Part no. 01 40 2 609 312 - \251 08/11 BMW AG