94 Prizm ABS light always on

I have a 94 Prizm I recently purchased that has 147,000 miles on it. When you start it ABS ACTIVE lights up in blue for a few seconds and then goes off, but the ABS light stays on all the time. The previous owner told me the light was on when he purchased it with 80,000 miles on it. He also said he slid into the back of a vehicle at one point so he knows the wheels lock up. Do I just need to have it put on a computer at the Chevrolet dealer or is this a common issue with these cars? Any ideas?