2001 BMW 540I SEDAN Owners Manual

Index
Data
Technology
Repairs
Car care
Controls
Overview
145nDisc brakes
Driving notes
When driving in wet conditions and in
heavy rain, it is effective to apply light
pressure to the brake pedal every few
miles (kilometers). Watch traffic condi-
tions to ensure that this maneuver does
not endanger other road users. The
heat which is generated by the brake
applications helps to dry the brake
pads and rotors.
Maximum braking force is obtained
while the wheels continue to rotate,
peaking when the wheels remain on the
verge of locking without actually doing
so. ABS maintains this state automati-
cally. If the ABS fails, you should revert
to the staggered braking technique
described below (refer to page 147).
Extended or steep mountain descents
should be driven in the gear in which
only minimal periodic brake applica-
tions is required. This avoids excessive
strain on the brakes and possible im-
pairment of the braking effect.
The braking effect of the engine can be
further increased by downshifting, into
first gear, if necessary. In the manual
mode of the automatic transmission,
you can also downshift into first gear.
Refer to page 76. Should engine braking prove inade-
quate, you should still avoid extended,
continuous braking. Instead of main-
taining low to moderate pressure over
an extended period of time, you should
decelerate by applying more substantial
pressure to the brake pedal (watch for
following traffic!), then releasing the
pedal, then repeating the application.
This staggered braking technique
allows the brakes to cool in the intervals
between active braking phases,
preventing overheating and ensuring
that full braking capacity remains avail-
able at all times.
Do not coast with the clutch de-
pressed or with the transmission
or selector lever in Neutral. Do not
coast with the engine shut off. The
engine provides no braking effect when
the clutch is depressed or the transmis-
sion is in neutral, and there is no
power-assist for braking or steering
when the engine is not running.
Never allow floor mats, carpets or any
other objects to protrude into the area
around the accelerator, clutch and
brake pedals and obstruct their move-
ment. <
Dynamic Brake Control (DBC)*
If you apply the brakes rapidly, this
system automatically produces the
maximum braking force boost and thus
helps to achieve the shortest possible
braking distance during "panic stops."
All of the benefits of the ABS system
are exploited under these circum-
stances.
Do not reduce the pressure on the
brake pedal for the duration of the
brake application. When the brake
pedal is released, the DBC is deacti-
vated.
In the event of a malfunction, the yellow
warning lamp comes on. Conventional
braking efficiency is available without
limitations.
Have the system checked and repaired
at your BMW center as soon as possi-
ble.
For "Information for your safety"
covering the ABS system, refer to
page 144. This information also gener-
ally applies for DBC. <

146nBrake system Winter operation
Brake fluid level
The warning lamp for the brake
hydraulic system comes on, or
the "CHECK BRAKE FLUID"
message appears in the Check
Control.
The brake fluid level is too low in the
reservoir (refer to page 168).
If the brake fluid level is too low and
brake pedal travel has become notice-
ably longer, there may be a defect in
one of the brake system's hydraulic
circuits.
Proceed to the nearest BMW
center. Higher brake application
pressure may be necessary under these
conditions, and brake pedal travel may
be significantly longer. Please remem-
ber to adapt your driving style accord-
ingly. <
The warning lamp comes on together
with the "CHECK BRAKE PADS" mes-
sage in the Check Control.
Brake pads
The warning lamp for the brake
pads comes on, or the "CHECK
BRAKE LININGS" message
appears in the Check Control:
The brake pads have reached their
minimum pad thickness. Proceed to the
nearest BMW center as soon as possi-
ble to have the pads replaced.
For your own safety: use only
brake pads that BMW has
approved for your specific vehicle
model. BMW cannot evaluate non-
approved brake pads to determine if
they are suited for use, and therefore
cannot ensure the operating safety of
the vehicle if they are installed. <
The onset of winter is often accompa-
nied by rapid changes in weather.
Adaptations in driving style should be
accompanied by preparations on the
vehicle itself to ensure that your vehicle
operation through the winter remains
safe and trouble-free.
Coolant
Ensure that the coolant mixture con-
tains the year-round ratio of 50: 50 of
water and antifreeze/corrosion inhibitor.
This mixture provides protection
against freezing down to approx. -34 7
(-37 6). Replace the coolant every four
years.
Locks
BMW door lock deicer can be used to
free the locks if they are frozen. This
deicer also contains lubricant.
After using deicer, treatment with BMW
lock barrel grease is recommended.

Index
Data
Technology
Repairs
Car care
Controls
Overview
147nWinter operation
Rubber seals and components
In order to prevent the weather-strip-
ping from freezing, apply BMW rubber
treatment or silicone spray to the seals
on the doors, hood and luggage com-
partment lid/tailgate.
A full range of car-care products is
available from your BMW center. <
Snow chains
BMW snow chains* can be mounted on
both summer and winter tires. Mount
them in pairs on the rear wheels only
and comply with the manufacturer's
safety precautions. Do not exceed a
maximum speed of 30 mph (50 km/h).
For maximum traction, we recommend
that you manually deactivate the
ASC+T/DSC
* when driving with snow
chains mounted. Refer to page 102.
Starting off
We recommend that you use the
manual control switch to deactivate
ASC+T/ DSC
* when starting off in deep
snow or when rocking the car to free it
(refer to page 102).
Driving on low-traction road
surfaces
Use smooth, gentle pressure to control
the accelerator pedal. Avoid excessive
engine speeds and shift to the next
higher gear at an early point. Adapt
your speed and driving style when ap-
proaching grades or slopes. Maintain
an adequate distance between yourself
and the vehicle ahead.
Brakes
Winter road conditions substantially
reduce the amount of traction available
between the tires and the road surface.
The resulting increases in braking dis-
tance are considerable and should be
kept in mind at all times.
ABS is intended to prevent the wheels
from locking during brake applications,
thus helping to maintain vehicle stability
and steering response. If the ABS does not respond in a critical
braking situation and the wheels lock:
reduce the pressure on the brake pedal
until the wheels just start to roll again
while still maintaining enough force to
continue braking.
Following that, increase pedal pressure
again. Reduce the pressure as the
wheels lock, then reapply pressure.
Repeat this procedure.
This type of staggered braking will
reduce the braking distance, and the
vehicle still remains responsive to
steering.
You can then attempt to steer around
hazards after you have reduced pres-
sure on the brake pedal.
Do not shift down on slick road
surfaces. Doing so could cause
the rear wheels to lose traction and
skid, which could result in the loss of
vehicle control. <
Depress the clutch during hard
braking on road surfaces which
provide only poor or uneven traction. <

148nWinter operation Power steering Level control system*
Skid control
Release the accelerator pedal and
depress the clutch pedal. Countersteer
carefully and attempt to regain control
of the vehicle.
Parking
Engage 1st or reverse gear. If your
vehicle is equipped with an automatic
transmission, place the selector lever in
"Park." On vehicles with manual trans-
mission, also apply the parking brake
when parking on inclined surfaces. In
order to prevent the parking brake pads
from locking due to frost or corrosion,
dry them by gently applying the parking
brake as the vehicle is coming to a
stop. Make sure that following traffic is
not endangered.
The brake lamps do not come on
when the parking brake is
applied. <
If there is a change in steering behavior,
for instance greater steering effort or if
steering becomes lighter as speed
increases in vehicles equipped with
Servotronic
*:
Contact your BMW center for an
inspection.
If the power steering fails,
increased effort will be required
to steer the vehicle. <
The warning lamp for the level
control system comes on, or the
message "LEVEL CONTROL
INACTIVE" appears in the Check
Control
*: there is a malfunction in the
level control system.
Stop and inspect the vehicle. If it is
riding significantly lower in the rear than
in the front, or if it is sitting at an incline
(left rear compared to right rear),
consult the nearest authorized BMW
center. Drive with appropriate caution
in the meantime. The vehicle has
reduced ground clearance or driving
comfort is noticeably reduced.
Even if the attitude of the vehicle is
normal, you should consult the nearest
BMW center if the warning lamp indi-
cates a system fault.

Index
Data
Technology
Repairs
Car care
Controls
Overview
149nCellular phone*Radio reception
Mobile communications systems (cellu-
lar phone, radio, etc.) are permitted
with an output of up to 10 watts only.
Even these systems may trigger mal-
functions in the operation of your vehi-
cle if they are not specifically designed
for use with the vehicle. BMW can nei-
ther test nor assume responsibility for
every individual product being offered
on the market. We recommend that you
consult your BMW center before pur-
chasing any device of this kind.
To ensure that your BMW continues to
provide reliable and trouble-free opera-
tion, do not use a cellular phone or
other radio device with an antenna
located inside the passenger compart-
ment. The antenna should always be
mounted on the outside of the vehicle.
Before loading the vehicle on a
car-carrier train or driving it
through a car wash, remove the
antenna. < The reception and sound quality
obtained from mobile radios varies
according to a variety of factors, includ-
ing the broadcast range of the transmit-
ter and the directional orientation of the
antenna. Interference factors such as
high-tension power lines, buildings and
natural obstructions can all lead to
unavoidable reception interference,
regardless of how well the vehicle
sound system is operating.
Climatic factors such as intense solar
radiation, fog, rain and snow can also
interfere with reception.
Cellular phones without official BMW
approval can also generate interfer-
ence. This phenomenon assumes the
form of a low-pitched hum emanating
from the speaker system.
Please refer to the Owner's Manual
provided with your audio system for
detailed information on its use.

150n
Information for your safety
The factory-approved radial tires are
matched to the car and have been
selected to provide optimum safety and
driving comfort on your vehicle.
It is not merely the tire's service life, but
also driving comfort and – above all else
– driving safety which depend on the
condition of the tires and the mainte-
nance of the specified tire pressure.
Incorrect inflation pressure is a frequent
cause of tire damage. It also signifi-
cantly influences the roadholding ability
of your BMW.
Check tire inflation pressures –
including the spare tire – regularly
(refer to page 29), at least every two
weeks and before beginning a longer
trip. If this is not done, incorrect tire
pressures can cause driving instability
and tire damage, ultimately resulting in
accidents. <
Tire tread – tire damage
Inspect your tires frequently for tread
wear, signs of damage and for foreign
objects lodged in the tread. Check the
tread depth.
Tread depth should not be allowed to
go below 0.12 in (3 mm), even though
the legally specified minimum tread
depth is only 0.063 in (1.6 mm). At a
tread depth of 0.063 in (1.6 mm), tread
depth indicators (arrow) in the tread-
groove base indicate that the legally
permissible wear limit has been
reached. Below 0.12 in (3 mm) tread
depth, there is an increased risk of
aquaplaning, even at relatively moder-
ate speeds and with only small amounts
of water on the road.
390de331
Do not drive on a deflated (flat)
tire. A flat tire greatly impairs
steering and braking response, and can
lead to complete loss of control over
the vehicle.
Avoid overloading the vehicle so that
the permitted load on the tires is not
exceeded. Overloading can lead to
overheating and increases the rate at
which damage develops inside the
tires. The ultimate result can assume
the form of a sudden air loss.
Unusual vibrations encountered during
normal vehicle operation can indicate
tire failure or some other vehicle defect,
as can variations in normal vehicle
response, such as a pronounced ten-
dency to pull to the left or right. Should
this occur, respond by immediately
reducing your speed and carefully
proceeding to the nearest BMW center
or professional tire center, or having the
vehicle towed in to have it and its tires
inspected.
Tire damage (up to and including blow-
outs) can endanger the lives of both the
vehicle occupants and other road
users. <
Tire inflation pressure Tire condition

Index
Data
Technology
Repairs
Car care
Controls
Overview
151nTire replacement
To maintain good handling and vehicle
response, use only tires of a single
tread configuration from a single manu-
facturer. BMW tests and approves
wheel/tire combinations. Refer to
page 153.
DOT Quality Grades
Treadwear
Traction AA A B C
Temperature A B C
All passenger car tires must con-
form to Federal Safety Require-
ments in addition to these grades. <
Treadwear
The treadwear grade is a comparative
rating based on the wear rate of the tire
when tested under controlled condi-
tions on a specified government test
course.
For example, a tire graded 150 would
wear one and one-half (1g) times as
well on the government course as a tire
graded 100. The relative performance
of tires depends upon the actual condi-
tions of their use, however, and may
depart significantly from the norm due
to variations in driving habits, service
practices and differences in road char-
acteristics and climate.
Traction
The traction grades, from highest to
lowest, are AA, A, B and C.
Those grades represent the tire's ability
to stop on wet pavement as measured
under controlled conditions on speci-
fied government test surfaces of as-
phalt and concrete. A tire marked C
may have poor traction performance.
The traction grade assigned to
this tire is based on straight-
ahead braking traction tests, and does
not include acceleration, cornering, hy-
droplaning, or peak traction character-
istics. <
Temperature
The temperature grades are A (the
highest), B and C, representing the
tire's resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Sustained high temperature can cause
the material of the tire to degenerate
and reduce tire life, and excessive tem-
perature can lead to sudden tire failure.
The grade C corresponds to a level of
performance which all passenger car
tires must meet under the Federal Mo-
tor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels
of performance on the laboratory test
wheel than the minimum required by
law.
The temperature grade for this tire
is established for a tire that is
properly inflated and not overloaded.
Excessive speed, underinflation, or ex-
cessive loading, either separately or in
combination, can cause heat buildup
and possible tire failure. <

152nTire replacement Tire rotation
Uniform Tire Quality Grading
Quality grades can be found where ap-
plicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA
Temperature A
Do not use retreaded tires, since
driving safety may be impaired.
This is due to the possible variations in
casing structures and, in some cases,
to their extreme age, which can lead to
a decrease in their durability. <
Tire age
The date on which the tire was manu-
factured is indicated by the code on the
sidewall:
DOT ... 2600 indicates that the tire was
manufactured in Week 26 of 2000.
BMW recommends the replacement of
all tires when the tires are no more than
6 years old, even if a tire life of 10 years
is possible.
Spare tires over 6 years old should be
used only in case of emergency. Such a
tire should be replaced by a new tire
immediately, and should not be
mounted together with new tires.
Between the axles
The tread wear patterns at the front end
differ from those at the rear – the actual
patterns will vary according to individ-
ual driving conditions. In the interests of
safety and maintaining optimal handling
characteristics, interaxle tire rotation is
not recommended.
If a proposed interaxle rotation of tires
is based on economic considerations,
one should consider whether the costs
for the rotation are likely to be recap-
tured by any increase in the service life
of the tires which might be realized. In
principle, interaxle tire rotation should
be performed at short intervals, with a
maximum of 3,000 miles (5,000 km).
Consult your BMW center for more
information.