2003 GMC Sierra 1500 Pickup Owner's Manual - Page 293

NORMAL: The indicator light will be off when the system is in this setting. Use for normal city and highway driving. Provides a smooth, soft ride when the vehicle is unloaded. FIRM (Unloaded): Press the switch to activate this setting, the indicator light will illuminate. Use this setting when road conditions or personal preference demand more control. Provides more "feel" or response to the road conditions. FIRM (Loaded): Press the switch to activate this setting, the indicator light will illuminate. Use this setting to minimize trailer inputs to the vehicle or when the vehicle is fully loaded. This setting is also appropriate for off-road driving. You can select a setting at any time based on road and trailering conditions to provide the best ride and handling. Select a new setting whenever driving conditions change. Steering Power Steering If you lose power steering assist because the engine stops or the system is not functioning, you can steer but it will take much more effort. Steering Tips Driving on Curves It's important to take curves at a reasonable speed. A lot of the "driver lost control'' accidents mentioned on the news happen on curves. Here's why: 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. 4-12 Experienced driver or beginner, each of us is subject to f the same laws o physics when driving on curves. The traction of the tires against the road surface makes it possible for the vehicle to change its path when you turn the front wheels. If there's no traction, inertia will keep the vehicle going in the same direction. If you've ever tried to steer a vehicle on wet ice, you'll understand this. The traction you can get in a curve depends on the condition of your tires and the road surface, the angle at which the curve is banked, and your speed. While you're in a curve, speed is the one factor you can control.