WARNING: This page is about a different car, the 1990 Buick Riviera and 1990 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
If this code is set as "history" and you are not experiencing braking problems, look for a short to ground in circuit No. 933. Shorted conditions would have to be present for at least 50 seconds.
Fig 1: Code B482: Circuit Diagram Anti-Lock Pressure Problem