brake light

I have a 95 sebring with abs my brake light is on. I have good brakes, no leaks , the light came on when the pedal went to the floor once. It pumped right up and has been fine since then. I found the back brakes to be loose and I tightened them up and it brakes great now. It has abs but that does not work. That's fine with me. It dosent pull left or right. so I didn't blead the fronts ( the bleaders are broke off , new calipers or drill and tap).Is it my parpotion valve if so how do I reset it and where is it? Any sugestion?

Thanks

Himie