See also:

Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...

Battery
The battery supplies power to start the engine and operate any additional electrical accessories. • To avoid break-down or failure to start the vehicle, maintain a battery with full crankin ...

STEP ON BRAKE TO RELEASE PARK BRAKE
This message is displayed if you attempt to release the electric parking brake without the brake pedal applied. See Parking Brake for more information. ...