2010 Buick LaCrosse Owner's Manual - Page 280

8-60 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. Conversions and Add-Ons Add-On Electrical Equipment Notice: Do not add anything electrical to the vehicle unless you check with your dealer/ retailer first. Some electrical equipment can damage the vehicle and the damage would not be covered by the vehicle's warranty. Some add-on electrical equipment can keep other components from working as they should. Add-on equipment can drain the vehicle 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 2‑36 and Adding Equipment to the Airbag-Equipped Vehicle on page 2‑37.