BMW 325xi Wagon (2001 year). Instruction - part 13
168nTowing the vehicle
Tow fitting
Rear:
Towing with a commercial tow
The screw-in tow fitting is stored in the
Using a screwdriver, press out the cover
truck
onboard tool kit; be sure that it remains
panel on the top part of the recess.
> Do not tow with sling-type equip-
in the vehicle at all times. This fitting
ment.
is designed for installation in the tow
Screw the tow fitting in until it
> Use wheel lift or flat bed equipment.
sockets located at the front and rear of
bottoms firmly. If this is not done,
the threads could be damaged.
> Please comply with applicable state
the vehicle. It is intended for towing on
Do not tow the vehicle by any compo-
towing laws.
paved road surfaces only. This fitting
should not be used to pull a vehicle out
nents of the running gear, or lash them
down in any way. If you do, the compo-
Never allow passengers to ride in
of deep snow, mud, sand, etc.
nents could be damaged, leading to
a towed vehicle for any reason.
Always observe all applicable towing
possible accidents.<
Never attach tie-down hooks, chains,
laws and regulations.
straps, or tow hooks to tie rods, control
arms, or any other part of the vehicle
Access to tow socket
suspension, as severe damage to these
Front:
components will occur, leading to
Using a screwdriver, press out the cover
possible accidents.c
panel on the top part of the recess.
Towing the vehicle
169n
BMW 325xi: tow the vehicle with
one raised axle
1 Place the gearshift lever or selector
lever in "Neutral."
2 Switch off the engine.
3 Towing speed:
Maximum 30 mph (50 km/h).
4 Towing distance:
Maximum 95 miles (150 km).
Remove the rear driveshaft for
longer towing distances with the
front axle lifted; remove the front drive-
shaft for towing over longer distances
with the rear axle lifted. Failure to
comply with this will result in damage to
the transfer box.<
170n
171n
Advanced technology:
Overview
Airbags
172
Adaptive Transmission Control
(ATC)
173
Automatic Stability Control plus
Traction ASC+T/Dynamic
Controls and features
Stability Control DSC
173
Radio reception
174
Four-wheel drive
175
Safety belt tensioner
175
Operation, care
Interior rearview mirror with
automatic dimmer
176
and maintenance
Rain sensor
177
Tire Pressure Control (RDC)
178
Self-diagnostics
179
Owner service procedures
Xenon lamps 180
Advanced technology
Technical data
Index
Technol-
172n
Airbags
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
Deceleration sensors continuously
with it dissipates.
monitor the acceleration forces acting
The entire process is completed within
upon the vehicle. If, as the result of
fractions of a second.
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 Head
Protection and side airbags in the front
or rear* are triggered if necessary.
ATC*
ASC+T/DSC*
173n
In order to include driving conditions in
Highly sensitive sensors monitor the
its calculations, ATC registers curves
number of revolutions of the wheels,
and both uphill and downhill gradients.
steering angle, lateral acceleration,
For example, if you maintain speed
brake pressure and the movement of
through a curve, the transmission does
the vehicle around its vertical axis.
not shift up. On uphill gradients, it shifts
If differences in the wheel speeds
up only when the engine speed
occur, ASC+T recognizes the danger of
increases in order to make more effi-
wheelspin and reduces torque. If
cient use of power reserves. On down-
necessary, the system also responds
hill gradients, ATC shifts down when
with additional brake applications at the
the speed of the vehicle increases and
rear wheels.
the driver must apply the brakes.
In addition, DSC permanently monitors
On vehicles with an automatic trans-
the vehicle's current operating condition
mission, the Adaptive Transmission
and compares it with an ideal condition
Control (ATC) uses a number of factors
that is calculated from the sensor's
to calculate the gear which provides
signals. If deviations from this occur
maximum efficiency. In this process, it
(understeering or oversteering, for
considers your individual driving style
instance), DSC can stabilize the vehicle
as well as current driving conditions.
in fractions of a second by reducing
ATC recognizes your personal driving
engine output and with the assistance of
style from the positions and movements
braking intervention at individual
of the accelerator pedal, deceleration
wheels. As a result, dangerous skids can
when braking, and lateral acceleration
be prevented even as they are just
through curves. Based on different shift
beginning.
characteristics - from comfort-oriented
You may need some time to become
to performance-oriented - ATC will
accustomed to this system's interven-
select the appropriate gear.
tion. However, it provides optimum drive
force and vehicle stability.
The braking intervention may be
accompanied by sounds specific to the
system.
174nRadio reception
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 trans-
mitting 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 AM frequency bands (medium-
the rear window to provide three sepa-
wave, long-wave and short-wave) make
rate sources for receiving broadcast
it possible to receive stations from a
waves. An integral processor automati-
great distance, because the broadcast
cally selects the antenna with the best
signals travel not only along the ground
FM reception quality at any given time.
as surface waves, but also as atmo-
The selection of the antenna takes place
spheric waves that are reflected from
within milliseconds, and is therefore not
the ionosphere.
noticed by the radio listener.
Frequency-modulation (FM) provides
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.
Four-wheel drive
Safety belt tensioner
175n
system intervention. Engine output is
also reduced if necessary.
When the DSC is deactivated, the
ADB-X traction intervention is set for
the maximum drive force. However, the
engine intervention and the stability
controls are no longer available. For
this reason, DSC should only be deacti-
vated in the exceptional circumstances
described on page 81.
The BMW 325xi is not an off-road
vehicle. Instead, permanent four-wheel
The transmission of power to the four
drive provides a high degree of vehicle
The safety belt tensioner responds to
drive wheels is provided permanently
stability and tractive ability under all
severe frontal collisions by tightening
through a transfer box. The distribution
road conditions, and will aid you in crit-
the belts to ensure that occupants
of torque between the front and rear
ical driving situations, e. g. driving in
remain firmly positioned in their seats.
axles is 38 % to 62%.
extreme winter conditions or on loose
A gas-pressure system retracts the
Traditional differential locks at the front
road surfaces.
buckle assembly to tension the
and rear axles and in the transfer box
shoulder and lap belts within fractions
are not required. Their function is
of a second. This reduces the tendency
assumed by automatic braking inter-
to slide under the lap belt.
vention at all four wheels. These trac-
tion interventions are governed by
Automatic Differential Brake (ADB-X), a
sub-function of DSC.
If a wheel tends to slip, it is braked
automatically by ADB-X until it once
again gains traction, and drive force
can be transmitted to that wheel. In
addition, the drive force is distributed to
the remaining wheels during this
176nInterior rearview mirror with automatic dimmer*
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.
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 light
sensor is mounted on the front of the
mirror housing. This sensor, the one
that is directed forward, measures light
intensity in the area ahead of the
vehicle. The second sensor is inte-
grated 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 incorporated in the lens.
Rain sensor*
177n
When the system is set to the "Intermit-
tent" wiper speed, the wipers react
immediately - if water is splashed onto
the windshield by vehicles traveling
ahead of you, for example. As a result,
the rain sensor contributes to driving
safety and comfort.
Depending on how wet the windshield
is, the rain sensor controls the opera-
tion 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 wind-
shield 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.
178nTire Pressure Control (RDC)*
There is an antenna located right near
every wheel in the vehicle body. This
antenna picks up signals from its
respective wheel. A central electronics
system evaluates the quadruple signals
which it receives and forwards any
changes.
The RDC provides an important contri-
bution to driving safety.
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 electronic chip which is
designed for severe-duty applications
and long service life. It contains a pres-
sure 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.
Self-diagnostics
179n
In the same manner, the electrical
You will hear the sounds of the air flaps
resistance of the airbag ignition genera-
as the air conditioning system/auto-
tors and all of the remaining airbag
matic climate control carry out their
components is measured at all times.
self-diagnostic functions after the igni-
Any fault in this system would be
tion has been turned off. All of the other
detected immediately by a current fluc-
self-diagnostics functions operate
tuation that would necessarily accom-
silently in the background.
pany it. The fault would be indicated
Any possible defects detected during
immediately by the airbag warning
these self-diagnostics can be read out
lamp.
by your BMW center and quickly
Even after you shut off the engine, the
corrected during the vehicle's next
overall functional status of your vehicle
regularly scheduled maintenance.
All of the important electrical and elec-
is monitored. For example, all of the
tronic systems in the vehicle are tested
flaps of the heating and ventilation
regularly and automatically; the driver
system travel to the nearest limit posi-
does not have to perform any extra
tion. This action ensures that the
operations or adjustments.
system will be able to provide
defrosting, regardless of other circum-
The indicator lamps also come on
stances, e. g. if a malfunction in the air
briefly after the ignition has been turned
conditioner/climate control system
on.
should occur during the night while the
While you are driving, the functional
vehicle is parked.
status of the actuator motors (for the
A calibration cycle runs every tenth time
windshield wipers, power windows,
the engine is shut off. During this cycle,
seats, sliding/tilt sunroof, etc.) is
the actuator motors move all air condi-
constantly analyzed by current
tioner/automatic climate control flaps to
measurements in their relays.
their limit stops in both directions. The
limit positions and the return travel
paths are checked in this manner in
order to ensure that appropriate adjust-
ments for the operating elements can
be made at any time.
180nXenon lamps*
Xenon lamps provide significantly
improved visibility, especially during
adverse weather and poor driving
conditions e. g. driving at night in heavy
rain or through road repair areas where
there are no lane markers.
Vehicles with xenon lamps are equipped
with an automatic headlamp range
control. Thus the highway is always
optimally lighted and drivers in
oncoming traffic are not blinded.
Xenon lamps make a significant contri-
The xenon lamp provides forward illu-
bution to highway safety since other
mination with significantly more bright-
highway users, bicyclists and motorcy-
ness and uniformity than the traditional
clists in the right lane, and pedestrians
halogen lamp.
are more easily detected.
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.
Maximum brightness is attained in
approx. 15 seconds.
Index
Data
Technology Repairs
Car care
Controls
Overview