XM Antenna on 09-10 Model

[DressedInBlack]

Can the XM antenna be used as a GPS antenna? I eventually will be buying an in-dash navigation head unit and I am hopeful that the existing antenna can be used for the GPS feature. Does anyone know if this is possible?

[ajb812]

This is something I've been researching myself for quite a while as I am looking to eventually add a in dash navigation unit as well. I doubt the factory XM antenna can be used for GPS, but it can be used for the aftermarket radio / XM tuner if you wish to retain the XM. As for the GPS, the factory roof antenna is for XM and OnStar (which is a GPS antenna and cellular antenna). If you don't have / don't want OnStar, what I've been looking into is using the GPS from the OnStar for the navigation unit. The vcim module is under the driver's seat, and the GPS connector is the blue one. You can just disconnect everything to the onstar vcim which I would recommend in this case (otherwise the vcim can't get a gps signal and kills the battery while trying - myself and some others here have disconnected it all with no problems). Then you would just need a cable to run from the driver's seat to the dash. I found a place that makes all sorts of custom cables ( http://www.cdint.com/catalog/category/Cables - I haven't used them yet so I can't comment on their products / service). The onstar cable connections are "Fakra" connectors which are just a SMB connection with a fancy plastic connector. The factory wires have female (plug) connectors, so the cable needed would be a male (jack) to the navigation connector (this would be dependent on the type of connector on the aftermarket unit). I am looking at the Pioneer AVIC - Z120BT and I think it's either an SMB or MCX connector for that unit - I haven't contacted pioneer yet to ask them.Sorry for the long answer - I've been doing a lot of research on this and just wanted to share what I've found. I'm fairly confident this would work (I've read of others who have had success using the OnStar GPS antenna in other GM vehicles for an aftermarket navigation unit), but I haven't tried it yet so I am not positive. Since there is already the factory XM / GPS / Cellular antenna on the car, the last thing I want to do is add more antennas for the aftermarket XM / GPS when what I need is already there. I will definitely be trying this though, and will update when I know more ...

[DressedInBlack]

thanks for the wealth of info! i figured there might be a way to use it; i sure hope it works. i too do not want to add another antenna while having a dead one on the roof. i won't be using the XM nor the OnStar so hopefully it can be used for something.im in no hurry to get the new head unit because im kinda broke, so hopefully somebody will come up with a surefire method in the meantime. for your sake, i hope yours is that method!