GMC 2002 Savana - Manual (Page 197)

4-8
Let’s say the road is wet and you’re driving safely.
Suddenly, an animal jumps out in front of you.
You slam on the brakes and continue braking.
Here’s what happens with ABS:
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at
both rear wheels.
The anti - lock system can change the brake pressure faster
than any driver could. The computer is programmed to
make the most of available tire and road conditions.
This can help you steer around the obstacle while
braking hard.
As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.