ABS codes can only be read by the dealer. It'll cost you 80 bucks minimum just to get the codes.
Possible issues and their costs:
1. Wheel speed sensor (part of the hub) $125 (assuming you know which one).
2. PMV (pressure modulator valve) located under the airbox. $500 new, $250 used.
3. EBCM (electronic brake control module) located on the firewall under the carpet to the right of your gas pedal. $750 new, $300 used.
Those are your major components. I suggest disconnecting all 4 WSS'* and cleaning the contacts, then reassemble them with dielectric grease for starters. Then decide if it'* worth the diagnosis and repair for you.