2003 Hummer H2 Owner's Manual - Page 251

When wheel spin occurs as the vehicle is moving, the driver may notice a slight shaking or shuddering of the vehicle. This is the indication that a loss of traction is occurring on this terrain. The operator should: 1. Reduce throttle. 2. Assess the terrain properly and adjust vehicle speed and gear ranges accordingly, 4HI or 4HI Lock position for higher speed, 4LO Lock for more torque and lower speeds. 3. Apply slight pressure to the brake when the shaking or shuddering sensation is felt, keeping the vehicle moving at a constant and controlled speed. 4. Be prepared to modulate the brake and throttle through the adverse terrain. For mounds, washouts, loose up-hill slopes, ditches, etc. 4-23