I have looked all over to find this answer and the dealership does not know as well. My radio after about 10 minutes or so (time will vary) screen will go blank, audio will spike and I am unable to turn it off. It looks like something is trying load or re-load-perhaps nav. system. After 15 to 30 minutes the radio will be fully functioning again. This does not happen everyday and some days are worse than others. I found a person who documented the exact problem on youtube (
) and there were several people who have the same problem with no solution.
2006 Yukon XL Denali