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:

What to Use
To determine what kind of fluid to use, refer to Recommended Fluids and Lubricants on page 11‑12. Always use the proper fluid. Notice: Use of the incorrect fluid may damage the vehicle and th ...

Automatic Transmission Shift Lock Control Function Check
WARNING When you are doing this inspection, the vehicle could move suddenly. If the vehicle moves, you or others could be injured. 1. Before starting this check, be sure there is enough room around ...

Auxiliary Battery
The auxiliary battery provision can be used to supply electrical power to additional equipment that may be added, such as a slide-in camper. If the vehicle has this provision, this relay will be loca ...