1998 GMC Suburban Owner's Manual - Page 199

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. This is normal. E\NTI - LOCK 1 If there's a problem with the anti-lock brake system. this warning light will stay on. See "Anti-Lock Brake System Warning Light" in 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 o n the brakes. Here's what happens with ABS. A computer senses that wheels are slowing down. If one of the wheels is about t o stop rolling, the computer will separately work the brakes at each front wheel and a t both rear wheels. 4-7