2006 Hummer H2 Owner's Manual - Page 265

You must wait for the light in the button to stop flashing and remain illuminated before the rear axle is locked. Notice: If you try to lock the rear axle while your vehicle is stuck and the tires are spinning, you could damage your vehicle's drivetrain. The repairs would not be covered by your warranty. Always lock the rear axle before attempting situations and/or navigating terrain which could possibly cause the vehicle to become stuck. The locking rear axle will be disengaged when the vehicle's speed is greater than 20 mph (32 km/h), if the vehicle's battery is low and/or the transfer case is shifted out of Four-Wheel-Low-Lock mode. Notice: If you lock the rear axle while driving on pavement, you could damage your vehicle's drivetrain. The repairs would not be covered by your warranty. Do not use the locking rear axle on pavement. If you need four-wheel drive when traveling on pavement, use only 4HI. Steering Tips It is important to take curves at a reasonable speed. A lot of the "driver lost control" accidents mentioned on the news happen on curves. Here is why: Experienced driver or beginner, each of us is subject to the same laws of 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 is no traction, inertia will keep the vehicle going in the same direction. If you have ever tried to steer a vehicle on wet ice, you will 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 are in a curve, speed is the one factor you can control. Suppose you are steering through a sharp curve. Then you suddenly accelerate. Both control systems - steering and acceleration - have to do their work where the tires meet the road. Adding the sudden acceleration can demand too much of those places. You can lose control. See Traction Control System (TCS) on page 4-9. What should you do if this ever happens? Ease up on the accelerator pedal, steer the vehicle the way you want it to go, and slow down. 4-11 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.