2540 Train prep reported intermittent br ~~~~~ Check and found #2540 EM to B3 slow release.FC-308/314/330/331.Swap CP transmitter to other car fault remain.Swap ACU to other car fault transfer.ACU replace and function test ok.No fault recure. #2540-ACU: New s/n: 1244-107 Old s/n: 1301-122 Not: 2318312 raise to RSW. Done by Koh. 29/09/21