abs code co265 co222 co281

hey man i got the tool but idk what the co281 code is and what it does ive repleace everything but the abs box its self i got it and someone repleaced the rear line and ive blade and blade and cycled the abs and some times u go to stop and it does not wont to stop what? do i do and it if is the abs box how do i bleed???? i have the matco md1052 tks bobby