ABS & Break Light Flash, 3 Beeps

Hi! Just recently as I'm driving my ABS & Break lights will flash and there will be a beep 3 times.. I just took my car up to where I bought it, and they checked it over and there doesn't appear to be any problems. The breaks are working good, it drives well, the break fluid is good. What could the problem be, or what else could I check? Thanks!

Make: Volkswagen
Model: Passat
Year: 1999
Mileage: 76550
Engine Size: 1.8L Turbo