Using the “Re-dial” Command
1. Press and hold 
for two seconds.
2. After the tone, say “Re-dial.” Once connected, the person called will be heard through the audio speakers.
See also:
Security Light
The security light should come on briefly as the engine is started. If the system is working normally, the indicator light turns off. If it does not come on, have the vehicle serviced by your dealer ...
Vehicle Security
This vehicle has theft-deterrent features; however, they do not make it impossible
to steal. ...
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. ...