2003 GMC Yukon Owner's Manual - Page 116

To Use the Engine Coolant Heater 1. Turn off the engine. 2. Open the hood and unwrap the electrical cord. The cord is located on the driver's side of the engine compartment, near the power steering fluid reservoir. If you have a diesel engine, refer to diesel supplement for location. 3. Plug it into a normal, grounded 110-volt AC outlet. 4. Before starting the engine, be sure to unplug and store the cord as it was before to keep it away from moving engine parts. If you don't, it could be damaged. How long should you keep the coolant heater plugged in? The answer depends on the outside temperature, the kind of oil you have, and some other things. Instead of trying to list everything here, we ask that you contact your dealer in the area where you'll be parking your vehicle. The dealer can give you the best advice for that particular area. {CAUTION: Plugging the cord into an ungrounded outlet could cause an electrical shock. Also, the wrong kind of extension cord could overheat and cause a fire. You could be seriously injured. Plug the cord into a properly grounded three-prong 110-volt AC outlet. If the cord will not reach, use a heavy-duty three-prong extension cord rated for at least 15 amps. Automatic Transmission Operation There are several different positions for your shift lever. Your vehicle is equipped with an automatic transmission and features an electronic shift position indicator within the instrument panel cluster. This display must be powered anytime the shift lever is capable of being moved out of PARK (P). PARK (P): This position locks your rear wheels. It's the best position to use when you start your engine because your vehicle can't move easily. 2-22