2001 GMC Safari Owner's Manual - Page 186

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. Here's how anti-lock works. Let's say the road is wet. 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. As you brake, your computer keeps receiving updates on wheel speed and controls braking pressure accordingly. 4-8