2684 - BCU Fault. To check & rectify. (Train Prep) ~~~~~ 2684 - BCU Fault.  (Train Prep)  2684 FC 301 (BCU Com. fault), 307 (BCU Com. Error 6), 308 (BCU Fault). ER downloaded, found BCU faulty. Swapped and replaced BCU from #2683 to #2684. #2683 BCU replaced. Wheel diameter setting done. Brake cyclic check - ok. Brake pressure - ok. All brakes able to release physically at coast. No    residual pressure at coast. Limited movement and depot shunting - ok. After swapped and replace BCU s/n: #2684: 18-47-08 #2683: 15-21-201 (New) Faulty: 15-41-284  Sarma/Alan/Lee PT 45456