2001 BMW 330Ci CONVERTIBLE Owner's Manual

185n
IndexDataTechnologyRepairsCar careControlsOverview

186n

Overview
Controls and features
Operation, care
and maintenance
Owner service procedures
Technical data
Index Advanced technology
187n
IndexDataTechnologyRepairsCar careControlsOverview
Adaptive Transmission Control
(ATC)188
Airbags189
Automatic Stability Control plus
Traction (ASC+T)/Dynamic
Stability Control (DSC)189
Radio reception190
Safety belt tensioner190
Interior rearview mirror
with automatic dimming
feature191
Rain sensor191
Tire Pressure Control (RDC)192
Self-diagnostics192
Rollover protection system193
Xenon lamps193
Technol-

188n
On vehicles with automatic transmis-
sion, the Adaptive Transmission Control
(ATC) uses a number of factors to
calculate the most efficient gear. In this
process, it considers your individual
driving style as well as current driving
conditions.
ATC recognizes your personal driving
style from the positions and movements
of the accelerator pedal, deceleration
when braking, and lateral acceleration
through curves. Based on different shift
characteristics Ð from comfort-oriented
to performance-oriented Ð ATC will
select the appropriate gear.
46cus020
In order to include driving conditions in
its calculations, ATC registers curves
and both uphill and downhill grades.
For example, if you maintain speed
through a curve, the transmission does
not shift up. On uphill grades, it shifts
up only when the engine speed
increases in order to make more effi-
cient use of power reserves. On down-
hill grades, ATC shifts down when the
speed of the vehicle increases and the
driver must apply the brakes.
ATC
*

189n
IndexDataTechnologyRepairsCar careControlsOverview
Deceleration sensors continuously
monitor the acceleration forces acting
upon the vehicle. If, as the result of a
frontal collision, a deceleration is
reached at which the protection of the
safety belts alone is no longer
adequate, the gas generators of the
driver and passenger-front airbags are
ignited. However, the passenger-side
airbag is only triggered if an additional
sensor has recognized that the
passenger seat is occupied.
In the event of a side collision, the side
airbags in the front and/or rear
* are
triggered if necessary.
390de012
The airbags located under the marked
covers inflate and unfold in a matter of
a few milliseconds. In this process, they
tear through the designed separation
points of the upholstered covers or
press them out.
Because the inflation process must be
virtually instantaneous, it is accompa-
nied by a certain amount of ignition and
inflation noise, which will be drowned
out by the noise from the accident
itself. The gas required to inflate the
airbags is not dangerous, and the
associated smoke then dissipates.
The entire process is completed within
fractions of a second.Highly sensitive sensors monitor the
number of revolutions of the wheels.
When equipped with DSC, they also
monitor steering angle, lateral accelera-
tion, brake pressure and the movement
of the vehicle around its vertical axis.
If differences in the wheel speeds
occur, ASC+T counteracts the danger
of wheelspin by reducing engine
torque; if necessary, ASC+T will also
respond by applying the brakes to the
rear wheels.
In addition, DSC permanently monitors
the vehicle's current operating condi-
tion and compares it with an ideal
condition that is calculated from the
sensor's signals. If deviations from this
occur (understeering or oversteering,
for instance), DSC can stabilize the
vehicle in fractions of a second by
reducing engine output and with the
assistance of braking intervention at
individual wheels. Dangerous skids are
thus prevented before they can even
start, and all of this is possible, of
course, only within physically possible
limits. You may need some time to
become accustomed to the system's
intervention. However, it provides
optimum drive force and vehicle
stability. The braking intervention may
be accompanied by sounds specific to
the system.
Airbags ASC+T/DSC
*

190n
Radio reception Safety belt tensionerThe AM frequency bands (medium-
wave, long-wave and short-wave) make
it possible to receive stations from a
great distance, because the broadcast
signals travel not only along the ground
as surface waves, but also as atmo-
spheric waves that are reflected from
the ionosphere.
Frequency modulation (FM) offers
substantially better sound quality than
the other frequencies. However,
because FM transmissions rely on line-
of-sight broadcast waves, their effec-
tive reception range is limited. 360de084
The limitations inherent to radio recep-
tion in a moving vehicle have been
minimized by a number of innovative
system designs:
The "Radio Data System" (RDS) makes
sure that, for broadcast stations
sending on several frequencies, the
radio automatically tunes to the
frequency with the best reception
quality.
The Antenna Diversity system employs
several FM antennas integrated within
the rear window to provide three sepa-
rate sources for receiving broadcast
waves. An integral processor automati-
cally selects the antenna with the best
FM reception quality at any given time.
The selection of the antenna takes
place within milliseconds, and is
therefore not noticed by the radio
listener.The safety belt tensioner makes sure
that the belt tightens during a head-on
collision to ensure that occupants
remain firmly positioned in their seats.
A gas-pressure system retracts the
buckle assembly to tension the
shoulder and lap belts within fractions
of a second. This reduces the tendency
to slide under the lap belt.
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191n
IndexDataTechnologyRepairsCar careControlsOverview
Interior rearview mirror with automatic dimming feature
* Rain sensor
*
The interior rearview mirror with auto-
matic dimming feature reduces blinding
from following traffic by adapting the
intensity of the reflected images to
correspond to levels of light registered
by the unit's sensors. The mirror reverts
to its undimmed setting as soon as the
light source disappears. One lamp
sensor is mounted on the front of the
mirror housing. This sensor, which is
directed forward, measures light inten-
sity in the area ahead of the vehicle.
The second sensor is integrated within
the mirror's glass. The electronic
control system compares the light
intensity from front and rear. The differ-
ence provides the basic parameter
used to modulate an electrical current
and induce chemical changes in a
semisolid layer incorporated in the lens.46cus036
The semisolid reacts chemically to this
electrical current, thus providing
dimming of the mirror through an infi-
nitely-variable range (electrochromic
technology).
As a result, it is no longer necessary to
dim the mirror manually, and the driver
can concentrate completely on traffic
conditions.
Depending on the degree of wetness on
the windshield, the rain sensor controls
the operation of the windshield wipers.
Infrared light is carried along the surface
of the windshield in an optical conductor
in such a manner that it is reflected
completely when the windshield is dry.
The quantity of reflected light is
measured. If there is moisture on the
glass, the amount of light reflected is
reduced since the infrared light at the
surface of the windshield can escape.
The quantity of reflected light is thus a
means of gauging the degree of wetness
on the windshield. When the system is
set to the "Intermittent" wiper speed, the
wipers react immediately Ð if water is
splashed onto the windshield by vehicles
traveling ahead of you, for example. As a
result, the rain sensor provides a contri-
bution to driving safety and comfort.
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192n
Tire Pressure Control* Self-diagnostics This system regularly checks tire pres-
sure and monitors all four tires even
while driving, so you do not have to.
Behind the valve stem in every wheel,
there is an extended-life electronic chip
that contains a pressure sensor, a
transmitter and a battery. The pressure
is measured in extremely short time
intervals and then transmitted by a
radio signal. If an irregularity is
detected, the transmission rate is
increased.
Located near each wheel and
embedded in the vehicle body is an
antenna that receives signals from the
wheel. A central electronics system
evaluates the quadruple signals and
forwards any changes.
The RDC provides an important contri-
bution to driving safety.46cde078
All
of the important electrical and elec-
tronic systems in the vehicle are tested
regularly and automatically Ð the driver
does not have to perform any extra
operations or adjustments.
The indicator lamps come on brießy
after the ignition has been turned on, for
example.
While you are driving, the functional
status of the actuator motors (for the
windshield wipers, power windows,
seats, etc.) is constantly being analyzed
by electrical measurements in the relays.
In the same manner, the electrical
resistance of the airbag ignition genera-
tors and all of the remaining airbag
components is measured at all times. Any
fault in this system would be detected
immediately by a current ßuctuation that 46cde052
would necessarily accompany it.
The fault
would be indicated immediately by the
airbag warning lamp.
Even after you shut off the engine, the
overall functional status of your vehicle is
monitored. For example, all of the ßaps of
the heating and ventilation system travel
to the nearest limit position. This action
ensures that the system will be able to
provide defrosting, regardless of other
circumstances, e. g. if a malfunction in the
air conditioner/automatic climate control
system
* should occur during the night
while the vehicle is parked.
A calibration cycle runs every tenth time
the engine is shut off. During this cycle,
the actuator motors of all the heating and
ventilation ßaps travel to their limit stops
in both directions. The limit positions and
the return travel paths are checked in this
manner in order to ensure that appro-
priate adjustments for the operating
elements can be made at any time.
You will hear the sounds of the air ßaps as
the air conditioner/automatic climate
control* carries out its self-diagnostic
functions after the ignition has been shut
off. All of the other self-diagnostics func-
tions operate silently in the background.
Any possible faults detected during these
self-diagnostics can be read out and
corrected by your BMW center
during the
next regularly scheduled maintenance.