2003 BMW 330i SEDAN brake

81
Under these special circumstances
traction is increased by deactivating the
control systems that enhance traction
under normal conditions.Deactivating the DSC and the
DTCPress the DSC button down for at least
3 seconds; the indicator lamp and the
yellow brake warning lamp will remain
on continuously.
The systems for enhancing stability and
traction are deactivated, and there is no
active braking intervention or torque
control.
To maintain vehicle stability,
always drive with the DSC acti-
vated whenever possible. cator lamp or the indicator lamps will go
out. DTC is deactivated.
The laws of physics cannot be
repealed, even with DSC. An
appropriate driving style always
remains the responsibility of the driver.
We therefore urge you to avoid using
the additional safety margin of the sys-
tem as an excuse for taking risks.
Whenever the DTC is activated, the
DSC is switched off and DTC performs
minor stabilizing intervention.
Do not make any modifications to the
DSC system. Allow only authorized
technicians to perform service proce-
dures on the DSC.<
Dynamic Stability Control (DSC)*
OverviewControlsMaintenanceRepairsDataIndex

82
Dynamic Stability Control (DSC) – BMW 325xi, 330xiThe conceptDSC maintains vehicle stability, even in
critical driving situations.
The DSC is operational every time you
start the engine.
DSC includes the Automatic Differential
Brake (ADB-X) and Cornering Brake
Control (CBC) functions.
Additional information on DSC is found
in the "Technology" brochure.Indicator lamp
The indicator lamp in the instru-
ment cluster goes out shortly
after the ignition has been
switched on; refer to page 20.
>The indicator lamp flashes: DSC is
actively controlling drive torque and
braking intervention
>The indicator lamp stays lit: DSC has
been switched off with the button;
ADB-X is operational. ADB-X control
intervention is not indicated.
If the indicator lamp fails to go out
when you press the DSC button,
this indicates a malfunction in the DSC
and ADB-X systems; the system is
deactivated, and the stability enhance-
ment functions are no longer avail-
able.<
The vehicle will remain completely
operational, however, without DSC. In
the event of a fault, please consult your
BMW center.
To deactivate DSCPress the DSC button; the indicator
lamp comes on and stays on.
DSC is now off, and ADB-X reverts to
its maximum torque-transfer mode.
In the following exceptional circum-
stances, it may be effective to deacti-
vate the DSC for a short period:
>When rocking the vehicle or starting
off in deep snow or on loose surfaces
>When driving with snow chains.
To maintain vehicle stability,
always drive with the DSC acti-
vated whenever possible.<

84
Hill Descent Control (HDC)*The conceptBy reducing the vehicle's speed on
steep downhill stretches, HDC main-
tains predictable vehicle handling
response to provide you with control of
your BMW during extreme descents.
The vehicle slows to a pace just slightly
faster than walking speed.
HDC is available for activation at vehi-
cle speeds below approx. 22 mph /
35 km/h. When driving down steep
hills, the vehicle reduces speed auto-
matically down to about double walking
speed – approx. 7.5 mph / 12 km/h –
and then maintains this speed at a con-
stant.
You can use the accelerator or brakes
to vary this speed within a range from
approx. 3 mph / 5 km/h to approx.
15 mph / 25 km/h.
In conjunction with the steering wheel
with multifunction buttons you can use
the +/– button to set the cruise control
to a target speed in the range from
approx. 3 mph / 5 km/h to approx.
15 mph / 25 km/h.
HDC is automatically deactivated once
vehicle speed again exceeds approx.
37 mph / 60 km/h.
To activate the systemPress the HDC button; the green indi-
cator lamp integrated within the button
comes on.
The indicator lamp flashes whenever
the system is actively intervening to
control your speed with automatic
brake applications.To deactivate the systemPress the button again, the indicator
lamp goes out.
HDC is automatically deactivated once
the vehicle accelerates to more than
37 mph / 60 km/h, as well as whenever
you switch off the ignition.
To use HDCVehicles with manual transmission:
You should always ensure that either
reverse or first gear is engaged before
using HDC, as the engine's braking
effect is most pronounced in these
gears, and only reduced engine braking
is available in higher gears.
Vehicles with automatic transmission:
HDC is available for use in all ranges.System malfunctionsAre signaled by the indicator lamp,
which responds to problems by going
out while HDC is in operation or by fail-
ing to come on when you activate the
system:
HDC has been temporarily deactivated
as a result of high brake temperatures.
If the DSC indicator lamp comes
on at the same time:
Malfunction in HDC and DSC
system. Refer the problem to your
BMW center.

86
If this occurs, reduce vehicle speed
immediately and stop the vehicle in a
safe location. Avoid hard brake applica-
tions. Do not oversteer. Replace the
defective tire, refer to page 141.
The space-saver spare tire is pro-
vided for temporary use only in the
case of a tire failure. It does not have
TPM electronics and is not monitored.
The spare tire that has the same dimen-
sions as the tires already mounted on
the vehicle is equipped with the neces-
sary TPM electronics and will also be
monitored once the tire has been
mounted and the system initialized.<
The TPM cannot alert you to
severe and sudden tire damage
caused by external factors.<
Have the tires changed by your
BMW center.
Your BMW center has the information
needed for working with TPM and is
equipped with the necessary special
tools. quency can interfere with TPM.
The yellow indicator lamp will come on
during the malfunction.
The indicator lamp also comes on
>in the event of a system fault
>if a wheel is mounted without the
appropriate electronics
>if, in addition to the spare tire, addi-
tional wheels with TPM electronics
are on board.
Please refer the problem to your BMW
center.
Flat Tire Monitor*The conceptAs you drive, the Flat Tire Monitor
keeps track of pressure levels in all four
tires in order to detect and warn of any
substantial pressure loss.
The system actually detects pressure
loss by monitoring differences in the
relative speeds of the four wheels. It
interprets variations outside specified
limits as severe pressure loss, and then
responds by generating a warning.
Tire Pressure Monitor (TPM)*

88
Flat tire
The red warning lamp in the
instrument cluster lights up to
warn of pressure loss and tire
failure. This visual alert is accompanied
by an acoustic warning signal. Reduce
your speed immediately, and steer and
brake gently as you bring the vehicle to
a stop.
To reset the warning lamp: after replac-
ing the damaged tire you will need to
reset the red warning lamp manually:
maintain pressure on the Flat Tire Moni-
tor button until the warning lamp goes
out. Then reinitialize the system.
The Flat Tire Monitor cannot pro-
vide you with advance warning of
sudden and severe tire damage caused
by external factors.
The system also does not detect the
gradual and minor loss of pressure that
all tires display over extended periods
of time.<
Check tire inflation pressures on a
regular basis, correcting them as
necessary; refer to page 25.
The system may respond to operation
on slippery or snow-covered road sur-
faces with false warnings or delays in
detecting actual pressure loss.
Performance-oriented driving – slip at
the drive wheels, high rates of lateral
acceleration – can also increase the
time that the Flat Tire Monitor requires
to detect a flat.<
System malfunctionsThe yellow indicator lamp in the instru-
ment cluster lights up and remains on
until the problem is corrected.
Please refer the problem to your BMW
center.
Flat Tire Monitor*

114Special operating instructions
Break-in proceduresTo ensure that your vehicle continues to
provide maximum economy throughout
an extended service life, we request
that you devote careful attention to the
following instructions.Engine and differentialThe first 1,250 miles/2,000 km:
Attempt to constantly vary both vehicle
and engine speeds during these initial
miles while remembering to avoid
engine speeds in excess of 4,500 rpm
and/or vehicle speeds of over
100 mph / 160 km/h:
Always obey all official speed limits.
Refrain from using full throttle and avoid
pressing the accelerator beyond the
kickdown point.
You can then proceed to increase both
engine and vehicle speeds once the ini-
tial 1,250 miles/2,000 km have elapsed.
Please remember to observe these
same break-in procedures if either the
engine or the differential should have to
be replaced later in the course of the
vehicle's service life.
TiresOwing to technical factors associated
with their manufacture, tires do not
achieve their full traction potential until
an initial break-in period has elapsed.
We thus ask you to drive with extra care
during the first 200 miles/300 km.
Always obey all official speed limits.
When the vehicle is operated on
wet or slushy roads, a wedge of
water may form between the tire and
the road surface. This phenomenon is
referred to as hydroplaning and can
lead to partial or complete loss of trac-
tion, vehicle control and braking effec-
tiveness. Reduce your speed on wet
roads. before the brake pads and rotors
achieve the optimal pad-surface and
wear patterns required for trouble-free
operation and an extended service life
later on.
To break in the separate parking brake
drums, apply the parking brake lightly
when coasting to a standstill – at a traf-
fic signal, for instance; use caution to
avoid posing a danger to other road
users.
You can prevent corrosion in the drums
by periodically repeating this proce-
dure.
The brake lamps do not come on
when the parking brake is set.
Vacuum for the brake system servo unit
on your BMW is available only when the
engine is running. When you move the
vehicle with the engine off – when tow-
ing, for example – substantially higher
levels of pedal force will be required to
brake the vehicle. before the clutch starts to operate at
optimum efficiency. Remember to
engage the clutch carefully during this
initial period.

115
Driving notes
Brakes: do not drive with your foot
resting on the brake pedal. Even
light but consistent pedal pressure can
lead to high temperatures, brake wear
and possibly even brake failure.
Hydroplaning: when driving on wet or
slushy roads, reduce vehicle speed. If
you do not, a wedge of water may form
between the tires and the road surface.
This phenomenon can lead to partial or
complete loss of contact between the
tires and road surface, as well as loss of
vehicle control and braking ability.
Driving through water: do not drive
through water on the road if it is deeper
than 1 ft/30 cm, and then only at walk-
ing speed. Otherwise, the vehicle's
engine, the electrical systems and the
transmission may be damaged.
Rear tray: never use it to store heavy or
hard objects, as otherwise occupants
could be injured during braking maneu-
vers.
Clothes hooks: when hanging clothing
from the hooks, be sure that they will
not obstruct the driver's vision. Do not
hang heavy objects on the hooks. If you
do so, they could cause personal injury
during braking or evasive maneuvers.<
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 the ABS system if you apply maxi-
mum pedal pressure – panic stop.
Since the vehicle maintains steering
responsiveness, 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 80.
The system responds to sudden, high-
intensity applications of force to the
brake pedal by automatically braking
the vehicle with maximum boost to
achieve the shortest possible braking
distances during "panic stops". This
system exploits all the benefits of ABS.Do not reduce the pressure exerted
against the brake pedal until the brak-
ing maneuver has been completed.
DBC is deactivated when you release
the brake pedal.
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.
OverviewControlsMaintenanceRepairsDataIndex

116
Brake systemBrake fluid levelIf the brake fluid level is too low and
brake pedal travel has become longer,
there may be a defect in one of the
brake system's hydraulic circuits.
Proceed to the nearest BMW cen-
ter. It may be necessary to apply
higher levels of pressure to the pedal
when stopping and braking distances
may also be longer. Please remember
to adapt your driving style accord-
ingly. 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; the pressure available
under the above conditions may not
provide adequate cleansing.
If the brake rotors are corroded, they
will tend to respond to braking with a
pulsating effect that even extended
brake applications will fail to cure.
When driving in heavy rain and on wet
roads it is a good idea to apply light
pressure to the brake pedal every few
miles. Monitor traffic conditions to
ensure that this maneuver does not
pose a hazard to you or to other road
users. The heat generated in this pro-
cess helps dry the pads and rotors to
ensure that your brake system will
respond with undiminished efficiency
when you need it.
When descending steep hills and
extended grades, downshift to a gear
that will allow you to continue safely
with only a minimal amount of braking.
By minimizing the loads placed on the
brake system, this strategy helps
ensure that optimal brake system
response will remain available at all
times. Use care to avoid exceeding the
approved engine-speed range, refer to
page 71.
Do not coast with the clutch
depressed or with the transmis-
sion or selector lever in Neutral. Do not
coast with the engine shut off. The
engine provides no braking effect when
the clutch is depressed and there is no
power-assist for braking or steering
when the engine is not running.
BMW 325xi, 330xi: always refer all
brake inspection and service work to
your BMW center, as failure to observe
the special procedures could result in
damage to components of the all-wheel
drive.
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. For your own safety: use only
brake pads that BMW has
released for your particular vehicle
model. BMW cannot evaluate non-
approved brake pads to determine if
they are suitable for use, and therefore
cannot ensure the operating safety of
the vehicle if they are installed.<