2010 GMC Canyon Extended Cab Owner's Manual - Page 276

Maintenance When Trailer Towing The vehicle needs service more often when pulling a trailer. See Scheduled Maintenance on page 7-3 or the Index for more information. Things that are especially important in trailer operation are automatic transmission fluid, engine oil, axle lubricant, belts, cooling system and brake system. It is a good idea to inspect these before and during the trip. Check periodically to see that all hitch nuts and bolts are tight. Trailer Recommendations Subtract the hitch loads from the Cargo Weight Rating (CWR). CWR is the maximum weight of the load the vehicle can carry. It does not include the weight of the people inside, but you can figure about 150 lbs. (68 kg) for each passenger. The total cargo load must not be more than the vehicles CWR. Weigh the vehicle with the trailer attached, so the GVWR or GAWR are not exceeded. If using a weight-distributing hitch, weigh the vehicle without the spring bars in place. The best performance is obtained by correctly spreading out the weight of the load and choosing the correct hitch and trailer brakes. For more information see Towing a Trailer on page 5-48. Trailer Wiring Harness The vehicle may be equipped with a four-pin trailer towing harness. This harness has a four-pin trailer connector that is attached to a bracket on the hitch platform. The four-wire harness contains the following trailer circuits: Yellow: Left Stop/Turn Signal Green: Right Stop/Turn Signal Brown: Taillamps/Park lamps White: Ground 5-60