See also:

Receiving a Call
When an incoming call is received, the audio system mutes and a ring tone is heard in the vehicle. ► Press . ► Press to ignore a call. ...

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. ...

Remote Keyless Entry (RKE) System Operation
The transmitter functions will work up to 20m(65 ft) away from the vehicle. Keep in mind that other conditions, such as those previously stated, can impact the performance of the transmitter. ...