Anybody know if the OnStar has a separate and distinct GPS module OR is the GPS built into the OnStar electronics box? I wish to tap into the GPS data and feed a laptop.

 

There have been hacks to do this just to prove it could be done, however there are many inexpensive USB/GPS receiver-antenna combos available that do exactly what you are looking for. Just Google USB GPS.

 

Each one of my other vehicles is set up with separate GPS units as you mention. A mount and GPS on the dash or windshield and an external antenna run to the outside of the vehicle, plus full time power for the GPS. Since the HHR already has the external antenna and GPS electronics for the OnStar I thought it would be a cleaner installation without the dash work for mounting and power & antenna cords into the dash. I do need the external antenna in the area I live - too tall of trees.

This of course is all for fun and is not used for navigation.

So if you could direct me to those hacks – it would be appreciated. If I can't hack into the on board GPS I will be doing a permanent antenna install on the roof of the vehicle. I don't yet have any wiring diagrams for the vehicle. I understand the OnStar unit is located behind the right rear seat in front of the wheel well.

 

I did a search for "onstar GPS hacks" and there is a ton of info out there. The problem is it looks like it's all pre-2006 onstar units. They mention Motorolla and Sony chips. The important part is figureing out what unit you have and what board is in it.

This link seems like the most helpfull in that department.
http://www.i-hacked.com/content/view/15/45/

Let us kow how you make out!

 

Oh No.

It looks like I have a lot more research to do. It seems all the information out there is based upon the old analog OnStar units and not the new digital units. Plus I am still under the initial free year of service and all the mods involve the use of an inactive/unsubscribed OnStar unit.

The OnStar unit operates using a proprietary data string from the Motorola embedded GPS that to my knowledge no common PC mapping programs can handle. So I will have to wait. The Motorola data string can be changed to a NMEA format, but then the GPS would not work for the OnStar.

 

You can easily buy a USB GPS instead of doing all those things. USB GPS are very cheap.

 

Yeah, and the software is not too badly priced! USB receiver included!! They have the USB receivers on the same page as well if that's all you want.
http://www.compuvisor.com/microsoft-...FQFvGgodC3PunQ