2009 Chevrolet Silverado 2500 HD Extended Cab Owner's Manual - Page 394

Safety Chains Always attach chains between the vehicle and the trailer. Cross the safety chains under the tongue of the trailer to help prevent the tongue from contacting the road if it becomes separated from the hitch. Instructions about safety chains may be provided by the hitch manufacturer or by the trailer manufacturer. If the trailer being towed weighs up to 5,000 lbs (2 271 kg) with a factory-installed step bumper, safety chains may be attached to the attaching points on the bumper. If the trailer being towed weighs up to the vehicle's trailer rating limit, safety chains may be attached to the attaching point on the hitch platform. Always leave just enough slack so the rig can turn. Never allow safety chains to drag on the ground. Tow/Haul Mode Pressing this button at the end of the shift lever turns on and off the tow/haul mode. This indicator light on the instrument panel cluster comes on when the tow/haul mode is on. Tow/Haul is a feature that assists when pulling a heavy trailer or a large or heavy load. See Tow/Haul Mode on page 2-34 for more information. 4-66