2003 GMC Yukon Owner's Manual - Page 289

If you keep pace with the traffic and allow realistic following distances, you will eliminate a lot of unnecessary braking. That means better braking and longer brake life. If your engine ever stops while you are driving, brake normally but do not pump your brakes. If you do, the pedal may get harder to push down. If your engine stops, you will still have some power brake assist. But you will use it when you brake. Once the power assist is used up, it may take longer to stop and the brake pedal will be harder to push. If there is a problem with the anti-lock brake system, this warning light will stay on. See Anti-Lock Brake System Warning Light on page 3-44. Anti-lock Brake System Your vehicle has anti-lock brakes. 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. Along with ABS, your vehicle has a Dynamic Rear Proportioning (DRP) system. If there is a DRP problem, both the brake and ABS warning lights will come on accompanied by a 10-second chime. The lights and chime will come on each time the ignition is turned on until the problem is repaired. See your dealer for service. 4-7