Transmission Software Update Oct 2016 and April 2017
Our XT5 got an update to the transmission computer software in October 2016 that solved transmission error codes until January 2017. Since then we have been in constant contact with GM Customer Care, the Regional GM Rep, and our Dealership. Last week we were told that there is a new software fix for the transmission computer due to be released in April 2017.
If you are having transmission error codes, make sure they have updated you to the October version and will let you know when the April version is available.
I am not holding my breath, but I could be pleasantly surprised.