See also:

OnStar®
If equipped, this vehicle has a comprehensive, in-vehicle system that can connect to a live Advisor for Emergency, Security, Navigation, Connection, and Diagnostic Services. See OnStar Overview on pag ...

Engine Coolant Heater
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 ...

Footnotes — Maintenance Schedule Additional Required Services — Severe
a) Or every two years, whichever comes first. b) Check all fuel and vapor lines and hoses for proper hook-up, routing, and condition. Check that the purge valve, if the vehicle has one, works properl ...