2012 GMC Canyon Owner's Manual - Page 226

9-54 Driving and Operating WARNING (Continued) . Driving with a Trailer { WARNING When towing a trailer, exhaust gases may collect at the rear of the vehicle and enter if the liftgate, trunk/hatch, or rear-most window is open. Engine exhaust contains Carbon Monoxide (CO) which cannot be seen or smelled. It can cause unconsciousness and even death. To maximize safety when towing a trailer: . Fully open the air outlets on or under the instrument panel. Adjust the Climate Control system to a setting that brings in only outside air and set the fan speed to the highest setting. See Climate Control System in the Index. . Before starting, check all trailer hitch parts and attachments, safety chains, electrical connectors, lamps, tires and mirror adjustments. If the trailer has electric brakes, start the vehicle and trailer moving and then apply the trailer brake controller by hand to be sure the brakes are working. This checks the electrical connection at the same time. During the trip, check occasionally to be sure that the load is secure, and that the lamps and any trailer brakes are still working. While towing a trailer or when exposed to long periods of sunshine, the floor of the truck bed may become very warm. Avoid putting items in the truck bed that might be affected by high ambient temperatures. For more information about Carbon Monoxide, see Engine Exhaust on page 9‑30. Towing a trailer requires a certain amount of experience. Get to know the rig before setting out for the open road. Get acquainted with the feel of handling and braking with the added weight of the trailer. And always keep in mind that the vehicle you are driving is now longer and not as responsive as the vehicle is by itself. Have the exhaust system inspected for leaks and make necessary repairs before starting a trip. Never drive with the liftgate, trunk/hatch, or rear-most window open. (Continued) .