The engine heater can provide easier starting and better fuel economy during engine warm-up in cold weather conditions at or below -18°C (0°F). Vehicles with an engine heater should be plugged in at least four hours before starting.

It is shipped from the factory with a tie holding it in place. Use care in removing the tie so that the cord is not damaged.
Check the heater cord for damage. If it is damaged, do not use it. See your dealer for a replacement. Inspect the cord for damage yearly.
Warning
Improper use of the heater cord or an extension cord can damage the cord and may result in overheating and fire.
Failure to use the recommended extension cord in good operating condition, or using a damaged heater or extension cord, could make it overheat and cause a fire, property damage, electric shock, and injury.
Keep the cord away from any moving parts.
If you do not it could be damaged.
The length of time the heater should remain plugged in depends on several factors. Ask a dealer in the area where you will be parking the vehicle for the best advice on this.
Starting the Engine
Retained Accessory Power (RAP)When It Is Time for New Tires
Factors such as maintenance, temperatures, driving speeds, vehicle loading, and
road conditions affect the wear rate of the tires.
Treadwear indicators are one way to tell when it is time for new tires.
Treadwear indicators appear when the tires have only 1.6mm (1/16 in) or less
of tread r ...
Navigation
OnStar navigation requires a specific OnStar subscription plan.
Press to receive directions or
have them sent to the vehicle navigation screen, if equipped.
Destinations can also be forwarded to the vehicle from MapQuest.com.
Turn-by-Turn Navigation
Press to connect to a live
Advisor.
...
Cooling System
The cooling system allows the engine to maintain the correct working temperature.
Engine Coolant Surge Tank and Pressure Cap
Engine Cooling Fan (Out of View)
Warning
An electric engine cooling fan under the hood can start up
even when the engine is not running and can cause injur ...