Saab 2007 9-3 Automobile User Manual


 
171Starting and driving
ABS brakes
The Antilock Braking System (ABS) modu-
lates the brake pressure to each wheel. The
pressure is automatically reduced just
before the wheel locks up and then
increases again to the point at which the
wheel is just about to lock. The wheel sen-
sors send information to the brake system’s
electronic control module for every 4 or so
inches (decimetre) that the car rolls. This
information is processed continuously to
ensure that the adjustment of the brake
pressure will be as exact as possible.
Adjustment takes place up to 12 times per
second.
The brake system provides Electronic
Brakeforce Distribution (EBD). This distri-
butes the brake pressure between the front
and rear wheels, in such a way as to achieve
optimum braking performance irrespective
of the car’s speed or load.
The ABS has a built-in diagnostics function
which will switch on the ABS warning light
if a fault is detected in the system (see
page 82).
The following message will appear on the
SID (and corresponding symbol on main
instrument unit) if a fault is detected:
WARNING
It is prudent to try your brakes from
time to time, especially when driving in
heavy rain, through water collected on
the road, in snow, on a wet road
surface or in salty slush. In such condi-
tions, the brakes may take longer than
normal to take effect. To rectify this,
touch the brake pedal periodically to
dry the brakes out.
The same applies after the car has
been washed or when the weather is
very humid.
Avoid parking the car with wet brakes.
Before parking, and if the traffic condi-
tions allow, brake quite heavily so that
the brake discs and pads warm up and
dry.
The brakes are power assisted and it
should be kept in mind that the servo
unit only provides the power assis-
tance when the engine is running.
The brake pressure required when the
engine is off, (e.g. when the car is
being towed) is roughly four times the
normal pedal force required. The
pedal also feels hard and unrespon-
sive.
Overheating can cause the brakes to
fade!
WARNING
The additional safety afforded by the
ABS system is not designed to allow
drivers to drive faster but to make
normal driving safer.
To stop as quickly as possible, without
loss of directional stability, whether
the road surface is dry, wet or slippery,
press the brake pedal down hard
without letting up (do not pump the
pedal), declutching simulta-
neously, and steer the car to safety.
Antilock brake malfunc.
Contact service.
93_U S_M 07.book Page 171 W ednesday, April 12, 2006 9:30 AM