It's an '01 Ram 2500, four wheel discs. While driving yesterday the ABS light came on, didn't overly concern me. But a few minutes later the regular BRAKE light came on as well. I did a visual & didn't find anything wrong, the braking effort thus far doesn't seem to have degraded any. I tried disconnecting the battery to see if maybe it had just been an electrical glitch & they might re-set but that didn't change anything. Could the master cylinder be bad & only either the front or rears are working? Being disc, maybe they just seem to be grabbing as normal? My jackstands are currently in use so I can't raise it up yet to see whether all four are grabbing. So I thought I'd come here to see what anyone can tell me. I'm currently unemployed so I can't afford to take it to a shop for a diagnosis. Thanks.