Usually a flashing or intermittent ABS light can be attributed to a bad OVP. Do a search on the forums for more info, but briefly, some of the solder connections inside the unit break causing all sorts of problems on your vehicle.

The unit can be found behind your battery, it is an aluminum, small square box with a red or black cap. There is a fuse located underneath this cap that you can check but usually the unit fails without the fuse blowing. I just replaced mine last year when it started causing my SRS and ABS light to flash. Solved my problem.

Good luck