2654 BCU FAULT FOUND DURING TRAIN PREP.  ~~~~~ 2654 BCU FAULT FOUND DURING TRAIN PREP. FC 308/331/330.  2654 FC 308 (BCU fault), 331 (BCU BCP fault Bogie2), 330 (BCU BCP fault Bogie1) Downloaded ER and found BCP stuck. Swap #1654 ACU  to #2654 and replaced #1654 with new spare. Function check - ok. BCP pressure - ok. No residual pressure at coast. All brakes able to release physically. Limited movement and depot shunting - ok. No signs of air leak on ACU. Swap and replaced ACU s/n: #1654: 1528/126 (new) #2654: 1429/014 faulty: 1516/107 (Old)  Sarma/Anand/Shafie 45390