1552 - BCU FAULT (TRAIN PREP) ~~~~~ 1552 BCU FAULT (TRAIN PREP).  1552 ER D/L, FC 308/330/331. ER showed braking abnormalities on #1552. Swapped #1552 ACU with #2551 & replaced new spare ACU on #2551. Brake cyclic check - OK. Brake pressure within criteria & no residual pressure at COAST.    No air leak found & no brake fault reoccurred. Limited movement/depot shunting - OK.  Sarma/Sugu/Lee PT/Shafie/Alan 45077 ACU S/N : #1552 : 1037/052 #2551 : 1301/122 (Faulty) #2551 : 1310-143 (New)