2013 Buick Verano Owner Manual - Page 240

9-56 . Driving and Operating Trailer Brakes Does the trailer have its own brakes? Be sure to read and follow the instructions for the trailer brakes so they are installed, adjusted, and maintained properly. Because the vehicle has antilock brakes, do not tap into the vehicle's brake system. If this is done, both brake systems will not work well, or at all. Will any holes be made in the body of the vehicle when the trailer hitch is installed? If so, seal the holes when the hitch is removed. If the holes are not sealed, dirt, water, and deadly carbon monoxide (CO) from the exhaust can get into the vehicle. See Engine Exhaust on page 9￿24. Conversions and Add-Ons Add-On Electrical Equipment Notice: Some electrical equipment can damage the vehicle or cause components to not work and would not be covered by the warranty. Always check with your dealer before adding electrical equipment. Add-on equipment can drain the vehicle's 12-volt battery, even if the vehicle is not operating. The vehicle has an airbag system. Before attempting to add anything electrical to the vehicle, see Servicing the Airbag-Equipped Vehicle on page 3￿28 and Adding Equipment to the Airbag-Equipped Vehicle on page 3￿29. 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. Leave enough slack so the rig can turn. Never allow safety chains to drag on the ground.