TC reported BCU emergency and BCP faultat rear M1. TC put MS to emergency to clear fault. TC report ed BCU emergency and BCP fault at rear M1. TC put MS to emer gencyto clear fault. ~~~~~ 1684 TC reported BCU emergency and BCP fault. TC put MS to emergency to clear fault. TC reported BCU emergency and BCP fault at rear M1. CE: 1684 having intermittent BCU fault. When in station Fault indication illuminated. Once departed station fault self cleared. Train performance ok, braking ok. Fc 330, 331  1684 ER D/L & found no FC but BCP no reading. Swapped #1684 BCU to #2684. Replaced new BCU on #2684. Security/function check - OK.  Abdillah/Junaidi/Fudail 44985 BCU S/N : (Before swapped) #1684 - 1449096 #2684 - 1544297 #2684 - 1544304 (NEW)