Onstar phone

roman traveler wrote:
OnStar uses the cellular system. How does it work when cell service is not available? I had it on all three of my vehicles, but with Bluetooth I dropped OnStar and just use my cell phone.

RT

OnStar uses a "high output amp" that is NOT available to you or I. I have heard 3W, but am not real sure. As long as there is "some" signal, even one you can't see, it will work.