ABS light goes on and off

my ABS light on my 94 gsr comes on and off but mostly stays on. i had this problum before and changed my break pads and the light went off. after about 2 months its back on and i also hear a little squeek sound but its not that loud and only somtimes. do any of you know whats up with the light or are my break pads worn out

did you change all the brake pads or just the front or rear?