by keithwbloom » May 21st, 2012, 6:53 pm
I appreciate your willingness to help, it is in fact very welcome. It is not the pin outs of the OnStar that I am most concerned about, the functionality of the analog OnStar systems does not vary greatly from marque to marque because they are mostly the same, widget-wise. It is the adaptation to the controller signals that I am most concerned about in the SAABs equipped with the optical loop bus. From my understanding, the optical loop bus is sort of like a token ring network, and the continuity of the ring is important (hence the descriptive "loop" in its moniker).
In scenarios where I have read about the OnStar system being deleted from 2003-2006 9-3s (because it went dark), I have learned that there needs to be a loop "repeater/relay" installed in its place to preserve the network connectivity for everything else on the bus. In each account I reviewed, I heard no telling of any other harness connection to the OnStar that led me to believe there were hardwired connections from the OnStar module to the head unit or button controller, both of which my adaptation in VW/Audi and Acura installations use to piggyback on or hijack completely. If the new 9-3s have used a series of purpose built transponders on the optical loop to send and receive signals and/or data from the systems peripherals (mic, buttons, head unit input) then unfortunately the adaptation is a non-starter. I just don't have any means or resources at my disposal to tinker my way through a solution that could work in such an environment.
If my reasoning is not accurate, and you have some insight to the actual landscape that would be of help, I am more than happy to work with you to try to find a solution based on BlueSTAR for the new 9-3 and other SAABs with similar network technology.
I would like to close with the observation that the previous generation 9-3 that does not have the optical loop bus is more compatible on paper with the present adaptation of the BlueSTAR for non-GM vehicles.