Subaru 2004 Impreza - Manual (Page 299)

7-30
Starting and operating
ABS (Anti-lock Brake System)
The ABS system prevents the lock-up of wheels which
may occur during sudden braking or braking on slip-
pery road surfaces. This helps prevent the loss of
steering control and directional stability caused by
wheel lock-up.
When the ABS system is operating, you may hear a
chattering noise or feel a slight vibration in the brake
pedal. This is normal when the ABS operates.
The ABS system will not operate when the vehicle
speed is below approximately 6 mph (10 km/h).
Always use the utmost care in driving – over-
confidence because you are driving with an
ABS equipped vehicle could easily lead to a se-
rious accident.
" The ABS system does not always decrease
stopping distance. You should always main-
tain a safe following distance from other vehi-
cles.
"
When driving on badly surfaced roads, gravel
roads, icy roads, or over deep newly fallen
snow, stopping distances may be longer for a
vehicle with the ABS system than one without.
When driving under these conditions, there-
fore, reduce your speed and leave ample dis-
tance from other vehicles.
"
When you feel the ABS system operating,
you should maintain constant brake pedal pres-
sure. Do not pump the brake pedal since doing
so may defeat the operation of the ABS system.
! ABS system self-check
You may feel a slight shock in the brake pedal and
hear the operating sound of ABS from the engine com-
partment just after the vehicle is started. This is
caused by an automatic functional test of the ABS sys-
tem being carried out and does not indicate any abnor-
mal condition.