2004 BMW M3 CONVERTIBLE wheel

86
Dynamic Stability Control DSCThe conceptDSC maintains vehicle stability, even in
critical driving situations.
The system optimizes vehicle stability
during acceleration and when starting
from a full stop, as well as optimizing
traction. In addition, it recognizes
unstable vehicle conditions, such as
understeering or oversteering, and,
within physically feasible limits, helps
keeping the vehicle on a steady course
by reducing the engine speed and
brake applications to the individual
wheels.
The system starts up automatically
each time you start the engine.The laws of physics cannot be
repealed, even with DSC. The
results of driving irresponsibly rest with
the driver. We therefore urge you to
avoid using the additional safety margin
of the system as an excuse for taking
risks. Do not make any modifications to
the DSC system. Allow only authorized
technicians to perform service proce-
dures on the DSC.
At first, you may need some time to
become accustomed to this system's
intervention. However, it guarantees
optimum drive force and at the same
time, the best possible vehicle stabil-
ity.<
Indicator lamp
The indicator lamp in the instru-
ment cluster will go out shortly
after the ignition has been
switched on, refer to page 19.
>Indicator lamp flashes: the system is
active and is controlling the drive
torque based on driving conditions
>If the indicator lamp fails to go out
after the engine has been started, or
if it comes on during normal driving
and stays on: the system has been
deactivated via the button or is
defective.
Please consult your BMW center for
repairs.
You can continue to drive the vehicle
normally without DSC.

88
System limitations
The Flat Tire Monitor cannot pro-
vide you with advance warning of
sudden and severe tire damage caused
by external factors and does not detect
the balanced and very gradual pressure
loss that takes place in all four tires
over an extended period of time.<
On the other hand, the following situa-
tions can lead to a delayed detection of
pressure loss and even to the system
not functioning:
>Driving on snow-covered or slippery
roads
>Performance-oriented driving: slip at
the drive wheels, high levels of lateral
acceleration
>When driving with snow chains, false
warnings and undetected pressure
losses may occur.
Initializing the system
Each time you correct the pres-
sure in a tire, or change a wheel or
tire, reinitialize the system immediately
afterwards. This requires a bit of driv-
ing.<
1. Before driving off, start the engine
but do not start driving
2. Press the button as long as you need
to until the yellow indicator lamp in
the instrument cluster lights up for a
few seconds
3. Drive off.
It takes a few minutes before the Flat
Tire Monitor can detect a flat tire and
issue a warning.
When driving with snow chains,
do not initialize the system.<
Flat Tire Monitor

89
To activate/deactivate the systemThe system is automatically activated in
ignition key position 2 and conse-
quently is on whenever the vehicle is
operated.
To deactivate the system: tap the but-
ton; the indicator lamp will light up yel-
low.
To activate the system: tap the button
again; the indicator lamp goes out.
Deactivate the system when snow
chains are mounted, since false warn-
ings and undetected losses in pressure
are possible under these kinds of con-
ditions.
Flat tire
The indicator lamp in the instru-
ment cluster lights up red. In
addition, an acoustic signal is
sounded.
1. Carefully reduce speed and come to
a stop. Avoid sudden braking and
steering maneuvers
2. Determine which wheel is damaged
If this cannot be determined, con-
tact your BMW center.<
3. Fix the flat tire using the M Mobility
system, refer to page 140.
After replacing the damaged tire, initial-
ize the system.
System malfunction
The indicator lamp in the instru-
ment cluster lights up yellow.
The Flat Tire Monitor is malfunc-
tioning or out of order. Please contact
your BMW center.
Flat Tire Monitor
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114
Antilock Brake System (ABS)The conceptABS keeps the wheels from locking
during braking, thereby enhancing
active driving safety.Braking with ABSIf you are in a situation that requires full
braking, you will exploit the full benefits
of ABS system if you apply maximum
pedal pressure – panic stop. Since the
vehicle maintains steering responsive-
ness, you can avoid possible obstacles
with a minimum of steering effort,
despite the full brake application.
Pulsation at the brake pedal combined
with sounds from the hydraulic circuits
indicates to the driver that ABS is in its
active mode.Dynamic Brake Control (DBC)DBC is included in the DSC, refer to
page 86.
If you apply the brakes rapidly, this sys-
tem automatically generates maximum
braking force boost and thus helps to
achieve the shortest possible braking
distance in panic braking situations. All
of the benefits of the ABS are exploited
under these circumstances.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.
Cornering Brake Control (CBC)CBC is an advanced engineering devel-
opment of ABS. When braking during
cornering with high lateral accelera-
tion, or when braking during a lane
change, vehicle stability is improved
and the steering response is enhanced.
Brake systemBrake fluid levelLow brake fluid level in the reservoir
combined with longer than usual pedal
travel may indicate a defect in one of
the brake system's hydraulic circuits.
Proceed to the nearest autho-
rized BMW center. Higher brake
application pressure may be necessary
when stopping, and the vehicle may
exhibit a slight tendency to pull to one
side. Brake distances may even be
longer. Please remember to adapt your
driving style accordingly. with the vehicle parked or in storage,
and operating conditions in which brak-
ing is restricted to gentle, low-pressure
applications will all increase the ten-
dency for corrosion to form on the
rotors; this is often accompanied by a
simultaneous accumulation of contami-
nation on the brake pads. The pads
must exert a certain minimal level of
pressure against the rotors for the disc
brakes' inherent self-cleaning effect to
remain effective.

118Wheels and tires
Tire inflation pressureInformation for your safetyThe factory-approved tires are matched
to your vehicle and have been selected
to provide optimum safety and driving
comfort when used properly.
It is not merely the tire's service life, but
also driving comfort and – above all else
– driving safety that depend on the con-
dition of the tires and the maintenance
of the specified tire pressure.
Incorrect tire inflation pressure is
a frequent cause of tire damage. It
also significantly influences the road-
holding ability of your BMW. Check tire
inflation pressures on a regular basis,
refer to page 25, 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 conditionTire tread – tire damageInspect 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 1/8 in / 3 mm, even though
the legally specified minimum tread
depth is only 1/16 in / 1.6 mm.
Below 1/8 in / 3 mm tread depth, there
is a great risk of hydroplaning, even at
relatively moderate speeds and with
only small amounts of water on the
road. Tread wear indicators in the
tread-groove base – see arrow – are
distributed around the wheel circumfer-
ence and are labeled on the tire side-
wall with TWI – Tread Wear Indicator. At
a tread depth of 1/16 in / 1.6 mm, the
indicators signal that the legally permis-
sible wear limit has been reached.

119
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 internal tire damage.
This can result in a sudden loss of tire
inflation pressure.
Unusual vibrations encountered during
normal vehicle operation can indicate
tire failure or some other vehicle defect.
This type of problem can be caused by
contact with curbs, etc. This is also true
for irregularities in the vehicle's han-
dling characteristics, such as a pro-
nounced tendency to pull to the left or
right. Should this occur, respond by
immediately reducing your speed. Pro-
ceed carefully to the nearest BMW cen-
ter or professional tire center, or have
the vehicle towed in to have it, its
wheels or 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 replacementTo maintain good handling characteris-
tics, only use a full set of tires of the
same brand and tread configuration.
Comply with the specified tire inflation
pressures, and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.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. 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 – 1
1/2 – 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.TractionThe 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
asphalt 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,
hydroplaning, or peak traction charac-
teristics. 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.
Tire condition
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120
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
Motor 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, under-inflation, or
excessive loading, either separately or
in combination, can cause heat buildup
and possible tire failure. applicable on the tire sidewall between
tread shoulder and maximum section
width. For example:
Treadwear 200 Traction AA
Temperature A
Tire ageThe date on which the tire was manu-
factured is indicated by the code on the
sidewall:
DOT ... 3603 indicates that the tire was
manufactured in week 36 of the year
2003.
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.Following wheel/tire changesComply with the specified tire inflation
pressures, and be sure to have the
wheel and tire assembly balanced
every time you change a tire or wheel.
Following wheel and/or tire changes
you will need to reinitialize both the
sequential M gearbox with Drivelogic
and the Flat Tire Monitor, refer to
pages 74, 88.
Tire replacement

121
Wheel and tire combinationsThe right choice
BMW recommends using only
wheels and tires that have been
approved by BMW for your particular
vehicle model, as otherwise body con-
tact and serious accidents can result
despite the use of the same nominal
size, e.g. due to manufacturing toler-
ances. If non-approved wheels and
tires are used, BMW cannot evaluate
their suitability, and therefore cannot be
held liable for driving safety.<
BMW tests certain tire brands for each
tire size, classifies them as road-safe
and approves them. Consult your BMW
center for more information. Observe
any country-specific regulations, e.g.
on making a corresponding entry in the
vehicle documents.
The correct wheel and tire combi-
nation affects different systems
such as ABS, DSC, Flat Tire Monitor.
The function of these systems is
impaired if improper wheel and tire
combinations are used.
Therefore, only use tires of the same
brand and same tread configuration on
the vehicle and, for example following a
tire failure, restore the approved wheel
and tire combination as soon as possi-
ble.<
The use of rims and lug bolts that
do not meet the specifications of
the original factory-installed equipment
will affect the safe operation of your
vehicle and may cause an accident and
personal injury.
Never mix tires of different design, such
as steel-belted radials with radial bias-
belted or bias-ply tires, etc. Mixing tire
types will adversely affect roadholding
and can lead to loss of vehicle con-
trol.<
StorageAlways store tires in a cool, dry place.
Store them away from light whenever
possible. Protect the tires against con-
tact with oil, grease and fuel.
Do not exceed the maximum tire infla-
tion pressures specified on the tire
sidewall.
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