To my understanding, the Bose amp supplies a good bit of information to the XLR and I believe that includes the ACC. I just posted a thread today about upgrading my audio system and adding a new amp with the factory amp still in place and noted that all steering wheel controls work, even ACC.Hi,
This info is a start and takes me further than I have been in the past few years with this issue.
All of my steering wheel controls work, and we have tested them. With that I don't think that I need anything from the factory radio or head unit. Its the power or communication to the ACC control module mounted inside the rear console. I might PM Gratch because he seems to be a little more in sync with what I describe, I have no idea how the power or connection is set up to the ACC module through the factory amp.
Thanks for the quick replies.