Train encountered BCU fault at Rear M2 car. Train gradually came to a stop at track circuit W554. ST BS operated to proceed to next station. Disembarked pax at R DH2. ~~~~~ 1640 encountered BCU fault. Train gradually came to a stop at track circuit W554. STBS operated to proceed to next station. Disembarked pax at RDH2. L3 L3 1640 ER D/L & found FC 314. 1640 ACU faulty - replaced. Brake pressure test - OK. Limited movement - OK. 1640 ACU S/N : OLD : 1538-153 NEW : 1528-135  Selvan/Lee PT/Anand 43892