My abs light has been on for about 5 years now. My problem is one of the wheel speed sensors has gone bad. I just don't want to spend 150 bucks just to find out which one it is. That being said you might have just gummed up the sprocket on one of the back wheels. Take off the tire and look for a sprocket behind the brakes and clean it with brake cleaner then check the sensor connections. The only place I know that can read the abs codes is the dealer. Ford made each sensor a different length on my 2000 gt so buying one and plugging it in each spot till the light goes off wont work for me. Good luck.