Hi there, I know you haven't been on the forum in a while but I'm having issues with an iDatalink Maestro SW in my car and you seem to have the same factory setup as me (2006 Bose with telephone/bluetooth module). Did you end up bypassing the bluetooth module? According to the guide I got when I flashed my Maestro SW I'm supposed to leave the bluetooth module harness unplugged, but I'm suspecting it supplies the 5V reference to the steering wheel controls. I have the correct resistances across signal a and b to ground when the buttons are pressed but no voltage with the key on.