TC reported RM1 (1540) car BCU fault, but fault indicator only appears when berthed at platform, notwhen train was on the move. TC reported all braking and per formance is normal, no signs of jerkiness. ~~~~~ #1540 fault code308/330/331. #1540 during brake cycle test found ACU air leak from exhaust port from B1 to coast.Replace ACU brake cyclic test and check ACU no air leak.No reoccurance of fault during function test.To be further monitor on M/L. ACU-New s/n: 1008-005  Old s/n: 1037-049 Not: 2195156 raise. Done by Zulq/Asruddin. 31/08/20