sensor BMW 325XI 2001 User Guide

146n
Washing your vehicle You can have your BMW washed in
an automatic car wash, even when it
is new. Car wash systems that do not
employ brushes are preferable.
Wipe away tough dirt and loosen and
remove dead insects before washing
the vehicle.
In order to avoid spots, do not wash the
vehicle when the hood is warm, or
during or immediately after exposure to
strong sunlight.
When using an automatic car wash, be
sure that:
>The car wash system is suited for the
dimensions of your vehicle.
>No damage will occur on vehicles
with attached body accessories (such
as spoilers or antennas). Consult the
car wash operator if necessary.
>The wheels and tires of your vehicle
cannot be damaged by the convey-
ance devices of the car wash system.
>The vehicle is cleaned with minimum
brush pressure, and that ample water
is available for washing and rinsing.Vehicles with rain sensor:
Clean the windshield regularly. Wax
from automatic car washes or insects
can cause malfunctions in the function
of the rain sensor.
Deactivate the rain sensor
(refer to page 70) when passing
through an automatic car wash. Failure
to do so could result in damage caused
by unintended wiper activation.<
Parts of the vehicle that are
inaccessible to the automatic washer Ð
such as door sills, door and hood
edges, etc. Ð should be cleaned by
hand.
In the winter months, it is especially
important to be sure that the vehicle is
washed on a regular basis. Large quan-
tities of dirt and road salt are difficult to
remove, and they also cause damage
to the vehicle.
If spray wands or high-pressure
washers are used, be sure to
maintain an adequate distance between
the spray source and the vehicle's
surface. Inadequate distance and
excessive pressure can damage or
weaken the finish, making it more
susceptible to subsequent attack. In
addition, moisture could penetrate to
vehicle components, leading to long-
term damage.<
When cleaning the headlamps,
please observe the following:
Do not clean by wiping with a dry cloth
(this causes scratches). Never use
abrasives or strong solvents. Remove
dirt and contamination (such as insects)
by soaking with BMW Car Shampoo
and then rinsing with plenty of water.
Always use a deicer spray to remove
accumulated ice and snow Ð never use
a scraper.<
After washing the vehicle, apply
the brakes briefly to dry them.
Braking efficiency might otherwise be
reduced by the moisture and the brake
rotors could also be corroded.<
Caring for your vehicle

149n
IndexDataTechnologyRepairsCar careControlsOverview
Caring for your vehicleWindow careYou can use window and glass cleaner
to clean inside window surfaces and
mirrors without smearing and streaking.
Never use polishing pastes or abrasive
(quartz) cleansers on mirror lenses.
Clean the wiper blades with soapy
water. The wiper blades should be
replaced twice a year Ð before and
after the cold season. This is especially
important for vehicles with a rain
sensor.
Use only wiper blades approved
by BMW.<
Caring for other vehicle
components and materials Light-alloy wheels should be treated
with alloy wheel cleaner, especially
during the winter months. However, do
not use aggressive products contain-
ing acids, strong alkalis or abrasives.
Do not use steam cleaners operating at
temperatures above 140 7 (+60 6).
Follow the manufacturer's instructions.
If your vehicle has chrome parts
* such
as the window frames and door handles,
clean these parts carefully with ample
clean water and a shampoo supplement
if desired, especially if they have an
accumulation of road salt. Use chrome
polish as an additional treatment.
Plastic components, vinyl upholstery,
headliners, lamp lenses, the clear cover
of the instrument panel and compo-
nents with a sprayed dull black surface
can be cleaned with water (add plastic
shampoo as required). Do not allow
moisture to soak through the seats or
headliner. Never use solvents such as
lacquer thinner, heavy-duty grease
remover, fuels, or similar substances.
Rubber components should be cleaned
with water only; a rubber treatment or
silicone spray may also be applied.Do not remove safety belts to clean
them. Clean them with mild soapy
water only. Do not use chemicals or dry
cleaners to clean safety belts, since this
could damage the belt fabric.
After cleaning, never allow the inertia
reel to retract the belts until they are
completely dry. Dirty safety belts
prevent the inertia reel mechanism from
retracting the strap properly, and thus
constitute a safety hazard.
Heavily soiled floor carpets and mats
*
can be cleaned with an interior cleaner.
The floor mats can be removed from
the vehicle for cleaning.
Use only a damp cloth to clean trim
panels made of real wood
* and other
parts constructed of real wood
*. Follow
up by drying with a soft cloth.
Use cleaning and car-care
products that you can obtain at
your BMW center.<

Overview
Controls and features
Operation, care
and maintenance
Owner service procedures
Technical data
Index Advanced technology
177n
IndexDataTechnologyRepairsCar careControlsOverview
Adaptive Transmission Control
(ATC)178
Airbags179
Automatic Stability Control plus
Traction (ASC+T)/Dynamic
Stability Control (DSC)180
Radio reception181
Four-wheel drive182
Safety belt tensioner183
Interior rearview mirror
with automatic dimming
feature184
Rain sensor185
Tire Pressure Control (RDC)186
Self-diagnostics187
Xenon lamps188
Technol-

179n
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 simultaneously. 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
and 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.
Airbags

180n
ASC+T/DSC
*
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 will also respond by
applying the brakes to the rear wheels.
In addition, DSC permanently monitors
the vehicle's current operating condition
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. As a result, dangerous skids can
be prevented even as they are just
beginning, but only within the laws of
physics.
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
accompanied by sounds specific to the
system.

184n
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
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.463us013
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.

185n
IndexDataTechnologyRepairsCar careControlsOverview
Rain sensor
*
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 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.390de133
When the system is set to the "Intermit-
tent" 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 contribution
to driving safety and comfort.

186n
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
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. 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
forwards any changes.
The RDC provides an important contri-
bution to driving safety.

Everything from A to ZFootwell lamps89
bulb replacement164
Four-wheel drive182
Front fog lamps89
bulb replacement161
Frost protection,
radiator142
Fuel28
Fuel consumption78
Fuel consumption
display75
Fuel filler door
releasing following an
electrical malfunction172
Fuel gauge75
Fuel injection192
Fuel quality28
Fuel reserve indicator
lamp75
Fuel specifications28
Fuel tank capacity195
Fuel tank gauge75
Functional status187
Fuses170 G
Gasoline28
Gasoline gauge75
Glove compartment104 Glove compartment lamp,
bulb replacement164
Gross vehicle weight194
H
Handbrake64
Handsfree system107
Hazard warning flashers26
Hazard warning triangle26
Head restraints48
Headlamp covers,
care146,159
Headlamp flasher69,89
Headlamp washer
system138,195
Headlamp washers71
Headlamps88
Heated seats103
Heating, rapid96
Heavy loads112
Height193
HiFi system Ð harman
kardon104
High beams23,69,89
bulb replacement159
High Performance Synthetic
Oils140
High-mount brake lamp163
Hood release134 Horn17
Hubcap166
Hydraulic Brake assistant,
refer to DBC
I
Ice warning77
Icy roads77
Identification, tires128
Ignition key32
Ignition lock62
Imprint4
Indicator lamps20
Inflated pressure28,125
Inflation pressure
monitoring86,186
INSPECTION75
Instrument cluster18
Instrument panel18
Interaxle tire rotation127
Interface socket108
for Onboard
Diagnostics154
Interference
cellular phone124
Interior lamps36,89
bulb replacement163
remote control36
Interior motion sensor42 Interior rearview mirror52
automatic dimming
feature53,184
Interlock62
Intermittent wipe69
J
Jack165
Jump-starting173 K
Key Memory53
Keys32
with remote control32 L
Lamps and bulbs158
LAMPS ON warning88
Lashing eyes112
LATCH attachment of the
child seat59
Leather care150
Length193
License plate lamp, bulb
replacement163
Light switch88
Light-alloy wheels130
Lighter108
Load-securing devices112

Everything from A to Z
203n
IndexDataTechnologyRepairsCar careControlsOverview
Louvers92,98
Low beam headlamps88
Low beams, bulb
replacement159
Lug bolts166
Lug wrench165
Luggage compartment41
capacity194
floor mat41
floor panel41
remote control37
Luggage compartment
lamps, bulb
replacement164
Luggage compartment
lid39
emergency release39
securing separately39
Luggage compartment
lighting39
Luggage rack113
Lumbar support49 M
M+S tires129
Maintenance75,145
Malfunction displays76
Manual transmission65
Manually controlled
recirculated-air101
Memory50 MFL (Multifunction steering
wheel)24
Microfilter95,171
Mirror memory50
Mirrors52
Mobile phone124
Modifications,
technical6,153
Motion sensor, interior42
Multifunction steering wheel
(MFL)24
N
Neckrest48 O
OBD interface socket154
Obstruction protection44
Odometer74
Oil
capacity195
consumption139
dipstick139
quality140
specifications140
viscosity140
Oil additives139
Oil change intervals, see the
Service and Warranty
Information Booklet
Oil filter change195 Oil level
check139
indicator lamp20
Oil pressure, indicator
lamp20
OILSERVICE75
Onboard tool kit158
Opening and closing Ð from
the inside38
Opening and closing Ð from
the outside34
Outside temperature
display77
Owner service
procedures206
P
Paint blemishes147
Paint, care147
Paintwork, minor
repairs148
Paintwork, waxing148
Park Distance Control
(PDC)79
Parking brake64
Parking help79
Parking lamps89
Parking, winter123
PDC (Park Distance
Control)79
Performance192
Phone, mobile124 Pocket flashlight104
Pollen95,102
Power seat49
Power steering123
Power windows44
safety switch45
Pressure monitoring,
tires86,186
Pressure, tires28,125
R
Radiator195
Radio Data System
(RDS)181
Radio reception124,181
Radio, refer to the separate
Owner's Manual
Rain sensor69,185
RDC (Tire Pressure
Control)86,186
RDS (Radio Data
System)181
Reading lamps90
Rear backrest, folding109
Rear lamps161
Rear window
defroster71,94,102
Rearview mirror52
Recirculated air mode94
Reclining seat47
Refueling27
Remote control35