2004 BMW 330I SEDAN brake

87
Dynamic Stability Control (DSC)The conceptDSC maintains vehicle stability, even in
critical driving situations.
The DSC is operational every time you
start the engine.
DSC incorporates the Dynamic Traction
Control (DTC) and Cornering Brake
Control (CBC) functions.
For information on vehicles with all-
wheel drive, refer to page 89 ff.Indicator lamps
The indicator lamp in the instru-
ment cluster goes out shortly
after the ignition has been
switched on; refer to page 19.
>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;
DTC and DBC are operational. DTC
control intervention is not indicated.
The indicator lamp and the
brake warning lamp continu-
ously light up in yellow:
The DSC, DTC and DBC have
been switched off manually or
there is a system malfunction.
The vehicle will remain completely
operational, however, without DSC. In
the event of a fault, please consult your
BMW center.
Indicator and warning lamps for
Canadian models.
Deactivating the DSC/activating
the DTCPress the DSC button briefly; the indi-
cator lamp comes on and stays on.
DSC is deactivated; DTC is operational.
In the following rare situations, it may
prove useful to activate the DTC for a
brief period:
>When rocking the vehicle or starting
off in deep snow or on loose surfaces
>When driving on snow-covered
grades, in deep snow, or on a snow-
covered surface that has been
packed down from being driven on
>When driving with snow chains.
OverviewControlsMaintenanceRepairsDataIndex

88
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repealed, even with DSC.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)

89
Dynamic Stability Control (DSC) – 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.Indicator lamps
The indicator lamp in the instru-
ment cluster goes out shortly
after the ignition has been
switched on; refer to page 19.
>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.<
OverviewControlsMaintenanceRepairsDataIndex

91
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 multifunction
steering wheel, you can use the +/–
button to set the cruise control to a tar-
get 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.
OverviewControlsMaintenanceRepairsDataIndex

93
When driving with snow chains or
a space-saver spare tire, do not
initialize the system.<
Flat tire
The indicator lamp in the instru-
ment cluster lights up red. This
visual alert is accompanied by
an acoustic warning signal.
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. Replace the damaged wheel, refer to
Changing a wheel on page 147.
After replacing the damaged tire, initial-
ize the system.
Vehicles with Run Flat tires:
1. Carefully reduce your speed to under
50 mph / 80 km/h. Avoid strong
braking and steering maneuvers. Do
not exceed a speed of 50 mph /
80 km/h.
Because the sides of Run Flat
tires are reinforced, a drop in infla-
tion pressure usually cannot be
detected from the outside, refer to Run
Flat tires, page 150.<
2. To continue driving, follow the
instructions under Driving with a
damaged tire on page 151.
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 refer the
problem to your BMW center.
Brake force displayThe brake force display indicates to the
driver of the vehicle behind you how
hard you are braking your vehicle.
The display has two levels:
>Normal braking: the brake lamps
among the rear lamps and the center
brake lamp light up
>Hard braking or use of ABS: the tail
lamps light up with the same bright-
ness as the brake lamps and thereby
intensify the visual effect of the brake
lamps.
Flat Tire Monitor*
OverviewControlsMaintenanceRepairsDataIndex

120Special operating instructions
Break-in proceduresTo ensure that your vehicle provides
maximum economy throughout a long
service life, we request that you
observe the following suggestions.Engine and differentialUp to 1,250 miles/2,000 km:
Constantly vary both vehicle and engine
speeds, remembering not to exceed
4,500 rpm or vehicle speeds of over
100 mph / 160 km/h:
Obey your local and state maximum
speed limits.
Do not use full throttle, and avoid
pressing the accelerator beyond the
kickdown point during these initial
miles.
You can then proceed to increase
engine or 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.
TiresDue to technical factors associated
with their manufacture, tires do not
achieve their full traction potential until
an initial break-in period has elapsed.
Thus drive with extra care during the
initial 200 miles/300 km.
Obey your local and state maximum
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, as well as loss of vehicle control
and braking effectiveness. 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 long 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.
To avoid corrosion, repeat this proce-
dure from time to time.
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.

121
General driving notes
Brakes: do not rest your foot on
the brake pedal while driving.
Even light but consistent pedal pres-
sure can lead to high temperatures,
brake wear and possibly even brake
failure.
Hydroplaning: when driving on wet or
slushy roads, reduce road speed. If you
do not, a wedge of water can form
between tires and 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 parcel tray: never use it to store
heavy or hard objects; otherwise, occu-
pants could be injured if the vehicle is
braked hard.
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 87.
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 sys-
tem 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
design of the ABS. When braking while
cornering at high speed or braking dur-
ing high lateral acceleration, or when
braking during a lane change, vehicle
stability is improved and steering
response is enhanced.
OverviewControlsMaintenanceRepairsDataIndex

122
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 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. sionally, during extended periods when
the vehicle is not used at all, and in
operating conditions where brake appli-
cations are less frequent, there is an
increased tendency for corrosion of the
rotors and accumulation of contamina-
tion on the brake pads. This occurs
because the minimal pressure that must
be exerted by the pads to clean the
rotors by brake applications is not
reached.
Corrosion on brake rotors is signaled by
a running or pulsation during braking;
even extended subsequent braking will
not cure this phenomenon.
It is a good idea to periodically dry the
brakes with a gentle application when
driving in rain and on wet roads. Watch
traffic conditions to ensure that this
maneuver does not endanger other
road users. The heat generated in this
process 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.
This helps avoid placing excessive
loads on the brake system. Use care to
avoid exceeding the approved engine-
speed range, refer to page 80.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.
325xi, 330xi: always refer all brake
inspection and service work to your
BMW center, as failure to observe the
special procedures could result in dam-
age 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.<
Brake pads
For your own safety: use only
brake pads which BMW has
approved for your specific 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.<