I experience the same intermittent working issues with my voice command button as well. Posted same under the 2013 section but, thought I would post it here as well. Had 2 such scenarios within the last month. Both times I got the voice command button working again by pushing and holding in the button while starting the vehicle and that seems to "reset" the button. Getting annoyed thought that this happens. I do not believe it is a mechanical issue with the button itself but definitely a SYNC issue.