See also:

Engine 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 hea ...

Compass
Compass Operation There is a compass display in the upper right corner of the mirror. Compass Calibration Press and hold to activate the compass calibration mode. CAL displays in the compass ...

Add-on Electrical Equipment
The OnStar system is integrated into the electrical architecture of the vehicle. Do not add any electrical equipment. See Add-On Electrical Equipment. Added electrical equipment may interfer ...