I had a similiar trouble w/ my car. Out of nowhere the ABS light would come on, the dinger would start sounding, and the Overdrive button wouldnt work anymore. This would continue until i changed the 10amp fuse, it was annoying as hell.

This would happen every ten miles or so, until i put a BIGGER FUSE IN IT 15amp..I wated a week to see if it would catch on fire so i could collect insureance money, nothing happened so i put the 10 amp back in, and it hasnt happened since. That was about 6 months ago..My car has had several little things like that happen. In your case the first thing i would do is start looking for a bad connection...Check the ABS Unit itself in the hatch of the car, and see if there are any loose wires. No problem fixes itself like that, if you have a repair manual the codes and their meanings should be in there.