2005 BMW 745i brake light

Driving
76 The vehicle brake lamps will automatically
illuminate to signal a following driver to take
action. In addition, it may be necessary for
the vehicle to downshift to maintain the dis-
tance setting selected. If the vehicle ahead
speeds up or when the lane ahead
becomes clear, your vehicle will accelerate
to the speed you have selected by increas-
ing the throttle setting and shifting gears as
needed.
Active cruise control is not and must
not be used as a collision avoidance/
warning system.<
Since this active cruise control sys-
tem is a new technology and operates
differently from conventional cruise control
systems which you may be accustomed,
you are strongly urged to read all of the
pages relating to this system before use.
Pay special attention to the information
contained in the Things to know about
active cruise control section in this manual
beginning on page78.<
Info Display screen contents
1Stored desired speed display
2Detected vehicle display. Lights up
when vehicle driving ahead is detected
3Selected distance to vehicle driving
ahead
4Digital speed display.
Appears briefly when you select your
desired speed, refer to page 77
The system is activated.
The display appears as soon as
you activate the system and no
vehicle is detected driving
ahead. Vehicle detected.
The display lights up when a
vehicle is detected driving
ahead.
The system requests you to
intervene by braking or with an
evasive maneuver. The display
flashes and a chime sounds.
The active cruise control cannot
automatically restore the distance to the
vehicle driving ahead. You will find more
detailed information on page 80.
Automatic intervention by ABS
or DSC, or you actuate the
parking brake while driving. The
active cruise control now only
intervenes by braking.
Operating active cruise control
1Activate system,
store and increase desired speed
2Activate system,
store and decrease desired speed
3Deactivate system
4With system deactivated:
Briefly press the button to recall the
stored speed and distance
4With system activated:
Increase desired speed by 1 mph/
1 km/h with each press of the button
5Select distance to vehicle driving
ahead. You can choose from four avail-
able distance settings. You will find
more detailed information on page 78

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Adjust your desired speed to the traf-
fic conditions and remain ready to
brake at all times. Great differences in
speed to the vehicles driving ahead, e.g.
when quickly approaching a truck or when
another vehicle swerves into your lane,
cannot be compensated for by the sys-
tem.<
Activate system
From approx. 20 mph/30 km/h you can
activate the system by pressing the lever
forward or pulling it back:
The current driving speed is stored as a
desired speed and briefly displayed in the
speedometer, refer to arrow.
If the display ACC --- mph/km/h
appears briefly in the speedometer,
it might be that conditions necessary for
operation are not currently being met.
To call up Check Control messages, refer
to page84.<
1 Desired speed store and increase
Press the lever forward:
The system applies and stores your current
speed as a desired speed. The speedome-
ter indicates this speed.
Subsequently pressing forward increases
the desired speed to the next 5-mile place/
10 km/h.
Each time the lever is pressed forward
again, the desired speed is increased by
another 5 mph/10 km/h until a maximum of
110 mph/180 km/h is reached. The speed
then displayed is stored and reached on a
clear road.
2 Desired speed store and decrease
Pull back the lever:
The current driving speed is rounded off to
the next 5-mile place/10 km/h, displayed
and stored.
Each time the lever is pulled back again,
the desired speed is decreased by another
5 mph/10 km/h until the minimum speed of
20 mph/30 km/h is reached. The speed
then displayed is stored and reached on a
clear road.
3 Deactivate system
Press the lever up or down while the sys-
tem is active. The displays in the speedom-
eter disappear. You can use the system
again as required.
In addition, the system is deactivated auto-
matically:
>When you apply pressure to the brake
pedal
>When you select the automatic trans-
mission's neutral range N
>When you deactivate the DSC Dynamic
Stability Control
>When you actuate the parking brake
during driving
>When the system reduces the speed to
below 20 mph/30 km/h due to a traffic
situation.
The system deactivates automatically
when the speed is set to below
20 mph/30 km/h. A gong sounds and a
message appears in the Check Control.
The active intervention of the driver is
required, otherwise there is an accident
danger.<
Background lighting
You can switch off the background lighting
of the speedometer and tachometer
>when you have deactivated the system
>when the prewarning field in the
tachometer has gone out, refer to
page81
>when the destination guidance system
of the navigation system is deactivated.

Controls
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Mobility
in city driving; heavy traffic such as during
rush hour; on curvy, winding roads, slip-
pery roads or roads with sharp curves such
as highway off-ramps; during inclement
weather such as snow, strong rain or fog;
or when entering interchanges, service/
parking areas or toll booths. It is also
important to regulate your vehicle's speed
and distance setting within applicable legal
limits. Always be ready to take action or
apply the brakes if necessary, especially
when the system is actively following a
vehicle in front of you.<
Always remember that the range and
ability of the system does have physi-
cal limitations. It will not apply the brakes or
decelerate your vehicle when there is a
slow-moving vehicle, stopped vehicle or
stationary object ahead of you, as for
example, at a traffic light or a parked vehi-
cle. Also, the system does not react to
oncoming traffic, pedestrians or other type
of potential traffic such as a rider on horse-
back. It is also possible that the system
may not detect smaller moving objects
such as motorcycles or bicycles. Be espe-
cially alert when encountering any of these
situations as the system will neither auto-
matically 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 alert-
ness.<
If while your vehicle is actively following a
vehicle 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, unob-
st r uc ted lan e w il l als o r esu lt in y ou r v eh icle
accelerating.
Be certain to deactivate the system
when you pull into an exit lane for a
highway off-ramp.<
Also, vehicles traveling in a staggered man-
ner 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 vehi-
cle actually in the lane next to you. Always be ready to take action or apply the brakes
if necessary.
Active cruise control can only decelerate
the vehicle to approx. 20 mph/30 km/h. If
the system reduces vehicle speed below
20 mph/30 km/h or if DSC/ABS is engaged
while driving, the system will automatically
deactivate.
Remember, the system cannot stop
your vehicle. In addition, the system is
deactivated whenever the driver applies
the vehicle brakes, shifts the transmission
from drive/D to neutral/N, or deactivates
DSC. After any deactivation, the system will
no longer automatically activate the vehicle
brakes, which means the driver must inter-
vene and resume manual braking. You
should then reactivate the system only
when you are fully aware of the prior speed
and distance settings.<
Active cruise control may brake when you
reduce the stored desired speed; however,
the driver must constantly monitor traffic
and intervene if necessary.
When you switch off the engine or ignition,
active cruise control is fully switched off,
too, and any settings you have selected are
canceled.
Behavior in curves
Because of the limited range of the system,
it is possible that in curves or on the peaks
and valleys of hilly roads, a vehicle ahead
may be recognized late, or not at all. There-
fore, it is up to the driver to select a speed
that is prudent in view of the curves and
terrain of the roadway.

Technology for comfort, convenience and safety
92
PDC with visual warning
You also enjoy the option of having the sys-
tem show distances to objects on the Con-
trol Display. The Control Display will also
indicate the presence of objects in green
before they are close enough to generate a
signal tone.
Select "PDC pic." from the "Settings" menu
and confirm your selection. This activates
the PDC display.
The display then appears on the Control
Display whenever the PDC is automatically
or manually activated.
The previous display automatically reap-
pears after the system is deactivated.
confirm to return to the previous dis-
play.
System limits
Even with PDC, final responsibility for
estimating the distance between the
vehicle and any obstructions always
remains with the driver. Even when sensors
are involved, there is a blind spot in which
objects cannot be detected. The system is
also subject to the physical limits that apply
to all forms of ultrasonic measurement,
such as those encountered with tow bars
and trailer couplings, as well as thin and wedge-shaped objects, etc. Low objects
already displayed, e.g. a curb, can also dis-
appear from the detection area of the sen-
sors again before a continuous tone
sounds.
Loud noises from outside and inside the
vehicle may prevent you from hearing the
PDC's signal tone.<
Keep the sensors clean and free of ice
or snow in order to ensure that they
will continue to operate effectively.
Do not apply high pressure spray to the
sensors for a prolonged period of time.
Keep the spray at least 4 in/10 cm away
from the sensors.<
Driving stability control
systems
Your BMW is equipped with an extended
array of systems designed to enhance and
maintain vehicle stability under extreme
conditions. The following section describes
these functions based on DSC and ABS.
ABS Antilock Brake System
ABS enhances active safety by preventing
the wheels from locking under braking.
ABS incorporates CBC and EBV.
Malfunction
The warning lamp lights up yellow
and ABS is switched off. Conven-
tional braking efficiency remains
available without limitations. Have the sys-
tem checked as soon as possible.
CBC Cornering Brake Control
CBC is a supplement to ABS. It provides
further enhancements in vehicle stability
and steering response during lane changes
and cornering at high rates of lateral accel-
eration.

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EBV Electronic brake-force
distribution
EBV controls the brake system's applica-
tion pressure at the rear wheels to ensure
stable deceleration.
DSC Dynamic Stability Control
The system optimizes vehicle stability dur-
ing acceleration and when starting from a
full stop, as well as optimizing traction.
The system recognizes any tendency for
the vehicle to assume an unstable attitude
such as oversteer or understeer; it then
counteracts this tendency with a combina-
tion of graduated reductions in engine
torque and selective braking intervention at
individual wheels. DSC provides optimized
stability within the limits defined by the
laws of physics.
The DSC is operational every time you start
the engine. DSC contains the functions
DTC Dynamic Traction Control and DBC
Dynamic Brake Control.
Indicator lamp
The indicator lamp goes out shortly
after the engine starts.
The indicator lamp flashes:
DSC controls the drive and braking forces.
The indicator lamp stays lit:
DSC has been switched off using the Con-
trol Center.
Activating DTC Dynamic Traction
Control
In particular driving situations, in deep
snow, for example, DTC ensures the maxi-
mum forward momentum. The gain in for-
ward momentum in these situations
involves a reduction in vehicle stability.
DTC is active up to 45 mph/70 km/h.You may find it useful to briefly activate
DTC under the following special circum-
stances:
>When rocking the vehicle and starting
off in deep snow or on loose road sur-
faces
>When ascending snow-covered hills,
and when driving in deep or on hard-
packed snow
>When driving with snow chains.
Select "Settings". Select "DTC" and con-
firm your selection. DTC is now activated.
The DTC indicator lamp in the Info Display
lights up permanently.
When DTC is active, DSC provides
only limited system response up to a
speed of approximately 45 mph/70 km/h.
Intervention for stability enhancement is
reduced.<
Deactivating DTC again
Select "Settings". Select "DTC" and con-
firm your selection. DTC is now deacti-
vated. The DTC indicator lamp in the Info
Display goes out. DSC is once again avail-
able without restriction.

Technology for comfort, convenience and safety
94
Switching off DSC
Select "Settings". Select "DSC" and con-
firm your selection. DSC is deactivated.
The indicator lamp in the Info Display
remains on continuously.
Deactivating DSC automatically deacti-
vates DTC as well. The systems for
enhancing stability and traction are deacti-
vated, and there is no active braking inter-
vention or torque control.
A status report appears in the Check Con-
trol. Please take note of the additional infor-
mation on the Control Display.
To maintain optimized stability, drive
with the system on whenever possi-
ble.<
Reactivating DSC
Select "Settings". Select "DSC" and con-
firm your selection. DSC is now activated.
The indicator lamp in the Info Display goes
out.
The laws of physics cannot be
repealed, even with DSC. An appro-
priate driving style always remains the
responsibility of the driver. Avoid using the
additional safety margin provided by the
system as an excuse for taking unneces-
sary risks.
When DTC is active, DSC provides only
limited system response up to a speed of
approximately 45 mph/70 km/h. Interven-
tion for stability enhancement is reduced.
Do not make any modifications to the DSC
system. Never allow anyone other than
authorized professional technicians to
carry out service or repairs on the DSC sys-
tem.<
DBC Dynamic Brake Control
When you apply the brakes rapidly, this
system automatically produces the maxi-
mum braking force boost and thus helps to
achieve the shortest possible braking dis-
tance during panic stops. This system
exploits all of the benefits provided by ABS.
Do not reduce the pressure on the brake
pedal for the duration of the brake applica-
tion. When the brake pedal is released, the
DBC is deactivated.
Malfunction in vehicle stability
control systems
The brake system warning lamp
lights up in red, appearing together
with the indicator lamps for ABS
and DSC. A status report appears in
the Check Control. Please take note
of the additional information on the
Control Display. Driving stability
control and ABS have failed. Con-
ventional braking efficiency remains avail-
able without limitations.
While you may continue, you should
remember to proceed cautiously and drive
defensively while avoiding full brake appli-
cations. Have the system checked as soon
as possible.
Display of the previously described
malfunction on Canadian models.
The DSC warning lamp lights up.
DSC and DTC have failed. Their sta-
bilizing interventions are no longer
available. The vehicle will remain com-
pletely operational, however, without DSC.
Have the system checked as soon as pos-
sible.
The brake system warning lamp
lights up yellow and a message
appears in the Check Control.
Please take note of the additional informa-
tion on the Control Display. DBC has failed.

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Vehicles with run-flat tires:
1.Cautiously reduce the vehicle speed to
below 50 mph/80 km/h. Avoid sudden
braking and steering maneuvers. Do not
exceed a vehicle speed of 50 mph/80
km/h
Due to the reinforcement on the
side walls of the run-flat tires,
inflation pressure loss can not usually
be recognized from the outside, refer to
Run-flat tires on page206.<
2.To continue driving, comply with the
instructions for driving with damaged
tires on page206.
Malfunction
The indicator lamp lights up yellow,
accompanied by a status message
in the Check Control. The Flat Tire
Monitor has malfunctioned or failed. Have
the system checked as soon as possible.
Self-leveling suspension*
Malfunction
A Check Control message appear-
ing together with this symbol indi-
cates a malfunction in the self-level-
ing suspension. Please take note of the
additional information on the Control Dis-
play.
Stop and inspect the vehicle. If the rear of
the vehicle is visibly lower than the front,
possibly accompanied by a tilt noticeable
when you compare the left rear with the
right rear, please respond by immediately
proceeding to the nearest BMW center.
Drive with appropriate caution in the mean-
time. The vehicle has reduced ground
clearance and driving comfort may be
noticeably reduced. Even if the attitude of
the vehicle is normal, you should consult
the nearest BMW center if the warning
lamp indicates a system fault.
Brake Force Display
The Brake Force Display indicates the
intensity with which you are applying your
brakes to drivers of following vehicles.
The display consists of two stages:
>Normal braking:
The brake lamps in the tail lamp assem-
blies and the high-mount brake lamp on
the rear tray light up during braking
>Heavy braking and braking with ABS:
The rear lamps also light up with the
same intensity as the standard brake
lamp units to enhance the warning
effect of the brake lamps.

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Hydroplaning
When driving on wet or slushy roads,
reduce road speed. If you do not, a
wedge of water can form between tires and
road surface. This phenomenon is referred
to as hydroplaning, and is characterized by
a partial or complete loss of contact
between tires and road surface, ultimately
undermining your ability to steer and brake
the vehicle.<
Driving through water
Only drive through water with a maxi-
mum depth of 1 ft/30 cm, and then
only at walking speed at the most. Other-
wise, the vehicle's engine, the electrical
systems and the transmission may be dam-
aged.<
Safe braking
Your BMW is equipped with ABS as stan-
dard equipment. The best way to brake is
to apply maximum pressure to the brake
pedal during emergency: full brake applica-
tion. Since the vehicle maintains steering
responsiveness, you can nevertheless
avoid possible obstacles with a minimum
of steering effort.
Pulsation at the brake pedal combines with
sounds from the hydraulic circuits to indi-
cate to the driver that ABS is in its active
mode.
Driving in wet conditions
While driving in wet conditions and in heavy
rain, it is a good idea to apply light pressure
to the brake pedal every few miles. Monitor
traffic conditions to ensure that this maneu-
ver does not endanger other road users.
The heat generated in this process helps
dry the pads and rotors to ensure that full
braking efficiency will then be available
when you need it.
Hills
To prevent overheating and reduced
efficiency of the brake system, drive
long or steep downhill gradients in the gear
in which the least braking is required. Otherwise, even light but consistent pedal
pressure can lead to high temperatures,
brake wear and possibly even brake fail-
ure.<
You can further enhance the engine's brak-
ing effect by selecting a lower gear in the
automatic transmission's manual mode,
downshifting as far as first gear on
extremely steep stretches, refer to
page70. This strategy helps you avoid
placing excessive loads on the brake sys-
tem.
Never allow the vehicle to coast with
the transmission in Neutral – or with
the engine switched off – as there is no
engine braking when the transmission is in
Neutral, and no power-assist for brakes
and steering when the engine is not run-
ning.
Never allow floor mats, carpets or any other
objects to protrude into the area around the
accelerator and brake pedals and obstruct
their movement.<
Corrosion on brake rotors
When the vehicle is driven only occasion-
ally, during extended periods when the
vehicle is not used at all, and in operating
conditions where brake applications are
less frequent, there is an increased ten-
dency for corrosion to form on rotors, while
contaminants accumulate on the brake
pads. This occurs because the minimal
pressure which must be exerted by the
pads during brake applications to clean the
rotors is not reached.
Should corrosion form on the brake rotors,
the brakes will tend to respond with a pul-
sating effect that even extended applica-
tion will fail to cure.
Mobile communications devices in
vehicle
BMW does not recommend using
mobile communications devices, e.g.
portable phones, in the interior of the vehi-
cle without a direct connection to an out-
side antenna. Otherwise the vehicle elec-
tronics and mobile communications device
can affect each other. In addition, it is not