BMW serie 3 sedan 2000 Manual Do Utilizador
106
n
Antilock Brake System (ABS)
The concept
ABS enhances active safety by helping
to prevent the wheels from locking un-
der braking. This is because locked
wheels are dangerous. When the front
wheels slide, the driver loses steering
control over the vehicle. Traction loss at
the rear wheels can cause the rear end
to break into an uncontrolled skid.
to prevent the wheels from locking un-
der braking. This is because locked
wheels are dangerous. When the front
wheels slide, the driver loses steering
control over the vehicle. Traction loss at
the rear wheels can cause the rear end
to break into an uncontrolled skid.
ABS is designed to meet two essential
requirements during every brake appli-
cation:
requirements during every brake appli-
cation:
>
To help provide vehicle stability
>
To help maintain steering control and
maneuverability – on all types of road
surfaces (asphalt, concrete, mud, wet,
snow, ice).
maneuverability – on all types of road
surfaces (asphalt, concrete, mud, wet,
snow, ice).
The system can achieve the shortest
braking distances possible under most
conditions (on straight-aways and in
curves, on asphalt, ice, wet road sur-
faces, etc.).
braking distances possible under most
conditions (on straight-aways and in
curves, on asphalt, ice, wet road sur-
faces, etc.).
Braking with ABS
The system becomes operative once
the vehicle exceeds a speed of approx.
6 mph (10 km/h). Below approx. 3 mph
(6 km/h), it is once again deactivated.
This means that the wheels can lock in
the final phase of a panic stop – a factor
of no significance in actual use.
the vehicle exceeds a speed of approx.
6 mph (10 km/h). Below approx. 3 mph
(6 km/h), it is once again deactivated.
This means that the wheels can lock in
the final phase of a panic stop – a factor
of no significance in actual use.
If you are in a situation that requires full
braking, you will exploit the full benefits
of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering re-
sponsiveness, you can avoid possible
obstacles with a minimum of steering
effort, despite the full brake application.
braking, you will exploit the full benefits
of the ABS system if you apply maxi-
mum brake pressure ("panic stop").
Since the vehicle maintains steering re-
sponsiveness, you can avoid possible
obstacles with a minimum of steering
effort, despite the full brake application.
The ABS system closed-loop control
circuit cycles in fractions of a second.
A pulsation at the brake pedal indicates
to the driver that ABS is active, that is,
that the vehicle is within its maximum
braking range. In addition, a pulsation –
a result of the control function cycles –
indicates to the driver that vehicle
speed should be reduced to adapt to
road surface conditions when there is
reduced traction and grip between tires
and road surface (slippery road sur-
face).
circuit cycles in fractions of a second.
A pulsation at the brake pedal indicates
to the driver that ABS is active, that is,
that the vehicle is within its maximum
braking range. In addition, a pulsation –
a result of the control function cycles –
indicates to the driver that vehicle
speed should be reduced to adapt to
road surface conditions when there is
reduced traction and grip between tires
and road surface (slippery road sur-
face).
On road surfaces that have a loose sur-
face layer on a firm base with good
traction (on gravel or snow, for exam-
face layer on a firm base with good
traction (on gravel or snow, for exam-
ple), or when snow chains are mounted,
braking distances may be longer than
with locked wheels. However, ABS
continues to provide enhanced vehicle
stability and steering response under
these conditions.
braking distances may be longer than
with locked wheels. However, ABS
continues to provide enhanced vehicle
stability and steering response under
these conditions.
Information for your safety
Not even ABS can suspend the laws of
physics. ABS cannot prevent the con-
sequences of brake applications with
inadequate clearances for safety be-
tween vehicles, when exceeding the
speed limit in curves, or the risks in-
volved when aquaplaning occurs. Re-
sponsibility for these types of situations
remains in the hands (and at the feet) of
the driver. You should never allow the
added safety of ABS to lull you into a
false sense of security, or mislead you
into taking increased risks that could af-
fect your own safety and that of others.
physics. ABS cannot prevent the con-
sequences of brake applications with
inadequate clearances for safety be-
tween vehicles, when exceeding the
speed limit in curves, or the risks in-
volved when aquaplaning occurs. Re-
sponsibility for these types of situations
remains in the hands (and at the feet) of
the driver. You should never allow the
added safety of ABS to lull you into a
false sense of security, or mislead you
into taking increased risks that could af-
fect your own safety and that of others.
Do not make any modifications to
the ABS system.
the ABS system.
Service procedures on ABS are to be
performed by authorized technicians
only.
performed by authorized technicians
only.
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