TIMS showed BCU fault intermittent at rear M2 car at 2 bogeys. No other fault indication. ~~~~~ #2539 BCU fault. FC-329, 328, 330, 304. Exhaust port leak. Replaced ACU and function test ok. ACU-New s/n: 1038-065.  Old s/n: 1019-017. Not: 2166501 raised to RSW. Done by Kalees/Gopal. 04/06/20.