BMW 323i 2000 Owners Manual

Overview
Controls and features
Operation, care
and maintenance
Owner service procedures
Technical data
Index Advanced technology
161n
IndexDataTechnologyRepairsCar careControlsOverview
Adaptive Transmission Control
(ATC)162
Airbags163
Dynamic Stability Control
(DSC)163
Radio reception164
Safety belt tensioner164
Interior rearview mirror
with automatic dimming
feature165
Rain sensor166
Tire Pressure Control (RDC)167
Self-diagnostics168
Xenon lamps169
Technol-

162n
On vehicles with an automatic trans-
mission, the ATC (Adaptive Transmis-
sion Control) uses a number of factors
to calculate the gear which provides the
maximum efficiency. 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 se-
lect the appropriate gear.
460us173
In order to include driving conditions in
its calculations, ATC registers curves
and both uphill and downhill gradients.
For example, if you maintain speed
through a curve, the transmission does
not shift up. On uphill gradients, it shifts
up only when the engine speed in-
creases in order to make more efficient
use of power reserves. On downhill
gradients, ATC shifts down when the
speed of the vehicle increases and the
driver must apply the brakes.
ATC
*

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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 ade-
quate, 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 Head
Protection and side airbags in the front
or rear
* are triggered if necessary.
390de319
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 necessarily
accompanied by a certain amount of
ignition and inflation noise. The gas
required to inflate the airbags is not
dangerous, and the smoke associated
with it 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,
the system counteracts the danger of
wheelspin by reducing engine torque.
If necessary, the system also responds
with additional application of the brakes
at the rear wheels.
If the system detects an instability in the
vehicle's condition, the braking action
can also be directed to the front wheels
by the DSC in order to help stabilize the
vehicle.
You may need some time to become
accustomed to this system's interven-
tion. However, it provides optimum
drive force and driving stability.
The braking intervention may be ac-
companied by sounds specific to the
system.
Airbags DSC

164n
Radio reception Safety belt tensionerAM radio provides reception across a
considerable distance because the
broadcast signals not only travel along
the ground as surface waves, but they
are also reflected from the ionosphere
as atmospheric waves.
Frequency-modulation (FM) provides
substantially better sound quality than
AM. However, because FM transmis-
sions rely on line-of-sight broadcast
waves, their effective reception range is
limited. 360de084
The limitations inherent to radio recep-
tion in a moving vehicle have been min-
imized by a number of innovative sys-
tem designs:
The "Radio Data System" (RDS) makes
sure that, for broadcast stations send-
ing on several frequencies, the radio
automatically tunes to the frequency
with the best reception quality.
The Diversity Antenna 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 there-
fore not noticed by the radio listener.The safety belt tensioner responds to
severe collisions by tightening the belts
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 re-
duces the tendency to slide under the
lap belt.
390de330

165n
IndexDataTechnologyRepairsCar careControlsOverview
Interior rearview mirror with automatic dimming feature
*
The interior rearview mirror with auto-
matic dimming feature reduces blinding
from following traffic by adapting the
intensity of the reflected images to cor-
respond 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 sen-
sor is mounted on the front of the mirror
housing. This sensor, which is directed
forward, measures light intensity 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 difference provides the
basic parameter used to modulate an
electrical current and induce chemical
changes in a semisolid layer incorpo-
rated in the lens.390de113
The semisolid reacts chemically to this
electrical current, thus providing dim-
ming of the mirror through an infinitely-
variable range (electrochromic technol-
ogy).
As a result, it is no longer necessary to
dim the mirror manually, and the driver
can concentrate completely on traffic
conditions.

166n
Rain sensor
*
Depending on the degree of wetness
on the windshield, the rain sensor con-
trols the operation of the windshield
wipers.
Infrared light is carried along the sur-
face of the windshield in an optical con-
ductor in such a manner that it is re-
flected 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 quan-
tity of reflected light is thus a means of
gauging the degree of wetness on the
windshield.390de133
When the system is set to the "Intermit-
tent" wiper speed, the wipers react im-
mediately Ð if water is splashed onto
the windshield by vehicles traveling
ahead of you, for example. As a result,
the rain sensor provides a contribution
to driving safety and comfort.

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IndexDataTechnologyRepairsCar careControlsOverview
Tire Pressure Control (RDC)
*
This system regularly checks tire pres-
sure and monitors all four tires even
while driving, so you don't have to.
Behind the valve stem in every wheel,
there is an electronic chip that is de-
signed for severe-duty applications and
long service life. It 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. 460de169
Near every wheel is an antenna in the
body that receives the signal from the
wheel. A central electronics system
evaluates the quadruple signals and for-
wards any changes.
The RDC provides an important contri-
bution to driving safety.

168n
Self-diagnostics 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 also come on
briefly after the ignition has been turned
on.
While you are driving, the functional
status of the actuator motors (for the
windshield wipers, power windows,
seats, sunroof, etc.) is constantly ana-
lyzed by current measurements in their
relays.460de177
In the same manner, the electrical re-
sistance 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 de-
tected immediately by a current fluctua-
tion that would necessarily accompany
it. The fault would be indicated immedi-
ately 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
flaps of the heating and ventilation sys-
tem travel to the nearest limit position.
This action ensures that the system will
be able to provide defrosting, regard-
less of other circumstances (if a mal-
function in the heating or ventilation
system should occur during the night
while the vehicle is parked, for in-
stance).
A calibration cycle runs every tenth time
the engine is shut off. During this cycle,
the actuator motors of all the heating
and ventilation flaps travel to their limit
stops in both directions. The limit posi-
tions and the return travel paths are
checked in this manner in order to en-
sure that appropriate adjustments for
the operating elements can be made at
any time.You will hear the sounds of the air flaps
as the heater/ventilation system carries
out its self-diagnostic functions after the
ignition is shut off. All of the other self-
diagnostics functions operate silently in
the background.
Any faults detected during these self-
diagnostics can be read out by your
BMW center during the next regularly-
scheduled maintenance and corrected
with a minimum of time.

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IndexDataTechnologyRepairsCar careControlsOverview
Xenon lamps
*
The xenon lamp provides forward illu-
mination with significantly more bright-
ness and uniformity than the traditional
halogen lamp.
In a xenon lamp, an electric arc replaces
the filament in order to generate intense
illumination. A gas mixture in a quartz
glass tube with metal vapor is ignited by
a high electric voltage. The arc that is
generated is then sustained by a lower
voltage. When the lamp is turned on,
there is a brief warm-up period. Maxi-
mum brightness is attained in approx.
15 seconds.390de134
Xenon lamps provide significantly-
improved visibility, especially during
adverse weather conditions and driving
situations, (driving at night in heavy rain
or through road repair areas where
there are no lane markers, for instance).
Xenon lamps make a significant contri-
bution to highway safety since other
highway users, bicyclists and motorcy-
clists in the right lane, and pedestrians
are more easily detected.

170n