TC reported TIMS show RM2 car BCU release fault. Train performance - OK ~~~~~ 2539 brake cyclic test, air leak check & checked for any hunting - All OK. Replaced ACU & function check brake operation - OK.  Ahmad/Afiq/Syukur/Suhairi 16/08/2021. #2539 ACU S/N : OLD : 1019/019 NEW : 1038/060