1998 GMC Safari Owner's Manual - Page 191

Anti-Lock Brakes (ABS) Your vehicle has anti-lock brakes (ABS). ABS is an advanced electronic braking system that will help prevent a braking skid. When you start your engine and 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. Thisis normal. If there's a problem with the this anti-lock brake system, warning light will stayon. See "Anti-Lock Brake System Warning Light" in the Index. ANTI LOCK \ Here's how anti-lock works. Let's say the roadwet. is You're driving safely. Suddenly animal jumps out in an front of you. You slam on the brakes. Here's what happens with ABS. A computer senses that wheels are slowing down. If one of the wheels is about stop rolling,the computer will to separately work the brakes each front wheel and at at both rear wheels. 4-7