ESP BMW 323i SEDAN 2000 E46 Service Manual

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.

169n
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.

So that you will have important specifi-
cations available when you stop to
refuel, we recommend that you supple-
ment this table with data that apply to
your vehicle.
Fuel
Engine oil The space between the two marks on
the dipstick corresponds to approx.
1.1 US quarts (1 liter). Designation
AKI: minimum
AKI: for rated performance
AKI: for enhanced perfor-
mance
Quality
Tire inflation pressure Summer Winter
Front Rear Front Rear
4 persons
5 persons or 4 plus luggageRefueling