Thanks so much for this post. I had my iPhone programmed before but did a restore last night night and lost my Bluetooth setting for my GMC Yukon. I have been looking all day for the command and this was definitely it. I have a 2007 GMC Yukon with a 2010 Chevy Traverse VCIM, Onstar fully functional and Bluetooth back is back in business.
Thanks again!!!!
after you hold the button for 2 seconds, instead of saying "bluetooth", say "onstar" first. After you say "onstar" then try to say "pair" or "bluetooth", i forget which, but that should get you working.