TireMan99

I had an inconsistent pedal (it would be soft then normal then feel like it was sticking) in my 2010 gmc 1500 4.8. Put it up on a lift checked for leaks or any lost brake fluid and there was none. Did some quick research came to the conclusion that it might be a master cylinder, so I bought a new M/C. Got it into the shop and figured I could at least try bleeding the brakes before installing new M/C. Ended up breaking a bleeder on the wheel cylinder and decided to do all new rear drums and shoes. Had been planning on doing this for a while and this just sealed the deal as i also had a leaking wheel seal and wanted to get that taken care of. After doing this the service brake light illuminated on my dash with no other codes or lights. Could it be a ABS module and if so how would I go about testing the module. Any and all advice is helpful still haven’t installed new M/C I am not as sure that’s the cause of my problems anymore.