If that doesn't work, there is a number of connectors under the windscreen (after you take off plastic bits and all). If you have a pinched wire, loose connector, it may be in there but start with the battery terminals first.
FYI - If you do unhook the battery to set them tight or to change out the bolt, you will get a SERVICE CHECK light on your display. Worry not. All it's telling you is that you need to set the date and time again. All your other settings remain!
Good luck!