2007 GMC Yukon Owner's Manual - Page 347

Using ABS Do not pump the brakes. Just hold the brake pedal down firmly and let anti-lock work for you. You may feel the brakes vibrate, or you may notice some noise, but this is normal. Braking in Emergencies With ABS, you can steer and brake at the same time. In many emergencies, steering can help you more than even the very best braking. Locking Rear Axle If your vehicle has this feature, your locking rear axle can give you additional traction on snow, mud, ice, sand or gravel. It works like a standard axle most of the time, but when one of the rear wheels has no traction and the other does, this feature will allow the wheel with traction to move the vehicle. As you brake, your computer keeps receiving updates on wheel speed and controls braking pressure accordingly. Remember: ABS does not change the time you need to get your foot up to the brake pedal or always decrease stopping distance. If you get too close to the vehicle in front of you, you will not have time to apply your brakes if that vehicle suddenly slows or stops. Always leave enough room up ahead to stop, even though you have ABS. 347