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 in at least four hours before starting.

An internal thermostat in the plug-end of the cord may exist which will prevent engine coolant heater operation at temperatures above −18°C (0°F).

If the vehicle has a diesel engine, see the Duramax Diesel supplement for more information.

See also:

Driving with a Trailer
WARNING When towing a trailer, exhaust gases may collect at the rear of the vehicle and enter if the liftgate, trunk/hatch, or rear-most window is open. Engine exhaust contains Carbon Monoxide (CO) ...

Transferring Service
Push to request account transfer eligibility information. The Advisor can assist in canceling or removing account information. If OnStar receives information that vehicle ownership has changed, OnSta ...

Services Provided
• Emergency Fuel Delivery: Delivery of enough fuel for the vehicle to get to the nearest service station. • Lock-Out Service: Service to unlock the vehicle if you are locked out. A remote unlock ...