After doing further research, I discovered that the entire unit must be completely disconnected. All the information that the unit receives comes from sensors throughout the vehicle. It is all fed to the OnStar "box" just like information from a lot of sensors in the OBDII engine management system is sent to the main ECU, then the ECU processes the information and sends signals back to control the FI, ignition timing, etc. It's the box that transmits all this information to the spy network. Soon they will probably start giving you speeding tickets based on OnStar information. This information could also be provided to insurance companies. I can remember a time when photo radar and red light cameras would have been unthinkable. Now they are everywhere.
To make sure the entire system is dead, the bluetooth part would have to be disconnected as well. Everything capable of transmitting a signal of any kind. This will not bother me at all. No only do I not use a cell phone while driving, I have a low tech pay as you go phone, and yes, it is turned off a great deal of the time. I am 55, and grew up in a time without cell phones. To me they are like a ball and chain around my neck. I carry mine mostly for emergencies, and check for messages a couple of times a day. Definitely not the type to have my life controlled by a phone.