2001 Chevrolet Lumina Owner's Manual - Page 155

And this warning light on the instrument panel will come on briefly when you start your vehicle. When you start your engine, or when you begin to drive away, your anti-lock brake system will check itself. You may hear a momentary motor or clicking noise while this test is going on, and you may even notice that your brake pedal moves or pulses a little. This is normal. If there's a problem with the anti-lock brake system, the anti-lock brake system warning light will stay on. See "Anti-Lock Brake System Warning Light" in the Index. 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. 4-8