1997 GMC Jimmy Owner's Manual - Page 215

Driving with a Trailer 1CAUTION: If you have a rear-most window open and you pull a trailer with yourvehicle, carbon nlonoxide (CO) could corne into yourvehicle. You can't see o r smell CO. It can cause unconsciousness or death. (See "Engine Exhaust" in the Index.) To maximize your safety when towinga trailer: Have your exhaust system inspected for leaks, and make necessary repairs before starting on your trip. Keep the rear-most windows closed. If exhaust does come into your vehicle through a window in the rear or another opening, drive with your front, main heating or cooling system on andwith the fan on any speed. This will bring fresh, outside air into your vehicle. Do not use MAX A X because it only recirculates the air inside your vehicle. (See " Comfort Controls" in the Index.) 4-50