Okay, so I have a 2001 Blazer and it came with the OnStar system. I activated the OnStar system and signed up for their basic service about 2 years ago. About 6 months ago or so, I got a letter from OnStar saying that the ANALOG OnStar system in my car was obsolete and would cease to function in like a year or something. Apparently, they've upgraded to a DIGITAL service and no longer support the older systems. A few months later, I called them and cancelled my service.
Anyway, so now I have an OnStar system that does nothing. I was trying to think of other uses for it. Since it has some sort of microphone/speaker system that goes through the radio, I was trying to figure out if there was a way I could use the existing wiring and somehow hook it up to my cell phone's audio jack. Basically, the OnStar button itself wouldtake the place ofthe buttonon a standard cell phone hands free kit, the OnStar microphone would be the phone's mic, and the audio, the radio. I think it's just a matter of rewiring a standard cell phone hands free kit. Most cell phones nowadays can use voice commands like "Call Mom" so in theory, it should work.
Has anyone ever tried this or know how the phone systems in other vehicles are hooked up and if they work this way? Just curious because I think it would be fun to try and do.
The only thing I have to lose is a useless OnStar system. :P

 

I just tried looking this up and found that you can actually use the chip as a GPS!
http://www.i-hacked.com/content/view/15/45/