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)Leaving the Vehicle with the Engine Running (Automatic Transmission)
Warning
It can be dangerous to leave the vehicle with the engine running.
It could overheat and catch fire.
It is dangerous to get out of the vehicle if the shift lever is
not fully in P (Park) with the parking brake firmly set. The vehicle can roll.
Do not leave the vehicle when the engine is ...
Brake Fluid
The brake/clutch master cylinder
reservoir is filled with DOT 4 brake fluid as indicated on the reservoir cap. See
Engine Compartment Overview on page 10-7 for the location of the reservoir.
There are only two reasons why the brake fluid level in the reservoir might go
down:
The brake fl ...
Connections
The required specific Onstar subscription plan includes the services that follow
to help customers stay connected.
For coverage maps, see www.onstar.com (U.S.) or www.onstar.ca (Canada).
WiFi Connectivity (If Equipped)
The vehicle has a WiFi hotspot that provides a high-speed, wireless Internet ...