Deutsch
EnglishAdvanced technology for your BMW 7 Series 2001-2007
187n
Airbags 188
Adaptive Transmission Control
(ATC) 188
Overview
Automatic Stability Control plus
Traction (ASC+T)/Dynamic
Stability Control (DSC) 189
Radio reception 190
BMW active seat 190
Safety belt tensioner 191
DSP sound system 191
Rearview mirror with automatic
dimmer 192
Controls and features
Operation, care
and maintenance
Rain sensor 192
Tire Pressure Control (RDC) 193
Xenon lamps 194
Owner service procedures
Advanced technology
Technical Data
Index
Technology
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
188nAirbags
ATC
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.
ATC
Because the inflation process must be
virtually instantaneous, it is necessarily
accompanied by a certain amount of ig-
nition and inflation noise. The gas re-
quired to inflate the airbags is not dan-
gerous, and the smoke caused by it
rapidly dissipates.
Deceleration sensors continuously
On vehicles with automatic transmis-
sion Adaptive Transmission Control
(ATC) uses a number of factors to cal-
culate the maximally efficient gear. In
this process it monitors your personal
driving style, the situation in which you
are driving, the condition of the road
and the traffic conditions.
monitor the physical forces acting upon
the vehicle. In a severe frontal collision,
the gas generators of the driver's airbag
and the front passenger airbag are ig-
nited. However, the passenger-side air-
bag is only triggered if an additional
sensor has recognized that the passen-
ger seat is occupied.
The entire process is completed within
fractions of a second.
ATC recognizes your personal driving
style from the positions and movements
of the gas pedal, declaration when
braking and lateral acceleration through
curves. Four shift characteristics – from
comfort-oriented to performance-ori-
ented – are available for selection by
ATC.
In the event of a severe side impact, the
head protection and side airbags in the
front and/or rear* are triggered.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
ATC
ASC+T/DSC
189n
In order to take driving conditions into
account, ATC registers corners and
both uphill and downhill gradients. For
By recognizing traffic conditions, ATC
can retain maximum driving comfort.
For instance, the system recognizes
Precision sensors monitor the wheel
speeds. The DSC also monitors steer-
ing angle, lateral acceleration, brake
pressure and the movement of the vehi-
cle around its vertical axis.
example, if you maintain speed through stop-and-go traffic and then proceeds
a curve, the transmission does not up-
shift.
only in second gear until it encounters
higher starting loads.
If differences in wheel speeds occur,
On uphill gradients, it shifts only when
the engine speed increases in order to
make more efficient use of power re-
serves. On downhill gradients, ATC
shifts down when the speed of the vehi-
cles increases, causing the driver to
step on the brakes.
Of course, the selector lever can still be the system recognizes the danger of
used to select specific gear ratios. Per- wheelspin and reduces the engine's
formance-oriented driving is enabled by drive torque. If necessary, the system
shifting from drive position "D" to "S,"
"3" or "2." Positions "3" and "2" each
limit upshifts to the next gear. Posi-
tion "2" is best for driving on steep
mountain slopes with a heavy load.
also responds with additional braking
intervention at all four wheels.
In addition, DSC permanently monitors
the vehicle's current operating condi-
tion and compares it with an ideal con-
dition that is calculated from the sensor
signals. If discrepancies from this ideal
condition (understeering or oversteer-
ing, for example) occur, DSC stabilizes
the vehicle in fractions of a second by
reducing engine power output and with
the assistance of braking intervention at
individual wheels. Dangerous skids are
thus prevented from the very beginning.
With respect to road conditions, ATC
monitors the friction between the tires
and the road. The system responds to
slippery road surfaces (snow and ice)
by activating the winter program.
Second gear is used when moving
away from a standstill, upshifts occur
sooner. On descents, downshifting
does not occur in spite of the applica-
tion of brakes. This enables you to
"feel" the road as you drive and pro-
duces greater dynamic stability. If the
friction between the tires and the road
is adequate, the normal system is again
activated. The system also leaves the
winter program when you shift from
drive position "D" to "S," "3" or "2," or if
the ASC+T/DSC* is deactivated.
You may need some time to become
accustomed to this system intervention.
However, it helps provide optimum pro-
pulsive force and driving stability.
The braking intervention may be ac-
companied by a certain degree of
noise.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
190nRadio reception
BMW active seat*
Although numerous factors combine to
impose inherent limitations on the re-
ception quality available from mobile
radios, specially designed systems can
be employed to minimize their effects:
With radio stations which broadcast
over multiple frequencies, the "Radio
Data System" (RDS) ensures that the
frequency with the best reception qual-
ity will automatically be selected.
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.
Because the ongoing antenna selection
process is completed within millisec-
onds, it remains inaudible to the radio
listener.
The active seat is an advanced devel-
opment in BMW seats. These seats are
engineered with orthopedic consider-
ations so that you will be less fatigued
during longer trips and sitting for long
periods without moving. The seat is no
longer a passive link between the road,
the running gear, and the driver. In-
stead, by means of an active modifica-
tion to the seat's surface, the seat
causes weight transfers which are
slight and imperceptible. The basic
seating position is not changed by this.
In the seat's upholstery, beneath the
surface of the seat, there is a cushion of
fluid on the left and right. The fluid is
slowly circulated back and forth be-
tween the cushions by means of a
pump.
Radio waves —mediumwave, long-
wave and shortwave —offer a wide
range of reception, because the broad-
cast signals travel not only along the
ground as surface waves, but also as
waves bounced back to earth from the
ionosphere.
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.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
BMW active seat*
Safety belt tensioner
DSP sound system*
191n
This causes a movement of the spinal
column which is barely detectable, to-
gether with an improvement in the flow
of blood to the intervertebral disks and
the muscle structure in the area of the
spinal column.
The passengers can experience less
muscle cramping, back pain in the lum-
bar region or symptoms of fatigue. As a
result, the active seat represents a sig-
nificant contribution to driving comfort
and driving safety.
The safety belt tensioner responds to The DSP Professional premium sound
severe collisions by tightening the belts system features a special amplifier
to ensure that occupants remain firmly
positioned in their seats. A gas-pres-
combined with Digital Sound Process-
ing (DSP) and integrated speakers to
sure system retracts the buckle assem- surround you with crisp, true-to-life
bly to tension the shoulder and lap belts sound reproduction.
within fractions of a second. This re-
duces the tendency to slide under the
lap belt.
The speaker system's subwoofers,
woofers, midrange speakers and tweet-
ers furnish you with an impressively full-
bodied listening experience. The indi-
vidual components are oriented so as
to produce the aural sensation that you
would experience facing the stage in a
concert hall. The system also automati-
cally adjusts the bass and treble set-
tings to compensate for changes in vol-
ume and vehicle speed.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
192nRearview mirror with automatic dimmer
Rain sensor*
The semisolid reacts chemically to this
electrical current, thus providing infi-
nitely-variable dimming of the mirror
(electrochromic technology).
As a result, it is no longer necessary to
dim the mirror manually, and the driver
can maintain full concentration on traf-
fic.
The interior rearview mirror with auto-
matic dimming feature reduces glare
from following traffic by adapting the in-
tensity of the reflected images to corre-
spond 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 of these
sensors is mounted on the front of the
mirror housing and is designed to mon-
itor light levels in the area forward of
the vehicle. The second sensor is inte-
grated within the mirror's glass. The
electronic control system operates by
comparing the respective levels of lumi-
nous intensity in front of and behind the
car. The difference provides the basic
parameter used to modulate an electri-
cal current and induce chemical
The rain sensor controls windshield
wiper operation, depending on how wet
the windshield is.
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.
changes in a semisolid layer incorpo-
rated in the lens.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
Rain sensor*
Tire Pressure Control (RDC)*
193n
When the system is set to the "Intermit-
tent" wiper speed, the wipers react im-
mediately – 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 driv-
ing safety and comfort.
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
forwards any changes.
The RDC provides an important contri-
bution to driving safety.
The Tire Pressure Control system as-
sumes the task of regular tire pressure
checks for you. Tire pressures are mon-
itored at all four wheels, even when the
vehicle is moving.
Behind the valve stem in every wheel,
there is an electronic chip which 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 de-
tected, the transmission rate is in-
creased.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
194nXenon lamps*
Xenon lamps provide significantly-im-
proved visibility, especially during ad-
verse weather conditions and driving
situations (driving at night in heavy rain
or through road repair areas where
there are no lane markers, for instance).
Vehicles with xenon lamps are
equipped with automatic-dynamic
headlamp range control. As a result, the
highway is always optimally lighted, re-
gardless of load conditions, and drivers
in oncoming traffic are not blinded.
The xenon lamps light up the side and
front areas of the vehicle with signifi-
cantly more brightness and uniformity
than the traditional halogen lamp.
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.
In a xenon lamp, an electric arc re-
places the filament in order to generate
intense illumination. A gas mixture in a
quartz glass tube with metal vapor is ig-
nited 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.
Maximum brightness is attained in ap-
prox. 15 seconds.
Online Edition for Part No. 01 41 0 004 597 - © 08/99 BMW Group
