On my S211 2006 the central display backlight disappeared yesterday, only to reappear on the next switch on. A few days ago the cluster clock time was out of sync with the COMAND time, which sync'd when I changed the time. Is this an emerging fault or is it telling me something else, the battery is sounding tired when starting with the cold and only short journeys. I would have expected the usual convenience functions disabled with a low battery? Any ideas?