Engine Coolant Heater

The engine coolant heater, if available, can help in cold weather conditions at or below −18°C (0°F) for easier starting and better fuel economy during engine warm-up. Plug in the coolant heater at least four hours before starting the vehicle. An internal thermostat in the plug-end of the cord will prevent engine coolant heater operation at temperatures above −18°C (0°F).

See also:

Fuel
For diesel engine vehicles, see “Fuel for Diesel Engines” in the Duramax Diesel Supplement. For Vehicles with gasoline engines, please read this. ...

Underbody Maintenance
Use plain water to flush dirt and debris from the vehicle's underbody. Your dealer or an underbody car washing system can do this. If not removed, rust and corrosion can develop. ...

Anti-theft Alarm System Messages
SERVICE THEFT DETERRENT SYSTEM This message displays when there is a problem with the theft-deterrent system. The vehicle may or may not restart so you may want to take the vehicle to your dealer bef ...