So I have an abs light and a brake light on but when I press the break it feels stiff and only the front brakes are working but if I unplug the abs module I have front and rear brakes again but I lose the speedometer and it won't shift so I need help figuring out what it could be I'm thinking possibly abs module if I had access to a scan tool I would check

 

What year is your truck? I am guess 4 wheel ABS? Most of the big chain parts stores will have a scanner that can read ABS codes. Whether they will or not, seems to be kinda random.

 

You also can ground one of the pins on the OBD plug and count the flashes.