TIMS showed intermittent BCU fault at car 1540. Train braking and performance is normal. Subsequentl y he reported car 2540 encountered intermittent BCU fault wh ile the fault at car 1540 self-cleared. ~~~~~ #1540 & #2540 Shown BCU fault (FC: 308,331,330). Further check found #1540 slow release during B1 to coast (750v cut off) BCU & ACU change out done. #2540 fault unable to duplicate. ER downloaded in PTU-002. BCU change out done and wheel diameter setting done. Brake test ok. BCP within criteria. From Tims found BCU brake demand PWM fault (FC:309), 6 cars happen at the same time. Notification: 2194651 raised to Signal to follow up. ACU-Old s/n: 1038-060.  New s/n: 1037-049.    Not: 2194655 raised to RSW. #1540-BCU-Old s/n: 1809055  New s/n: 1813110. #2540-BCU-Old s/n: 1824244  New s/n: 1816160. Done by Sanip/Koh. 30/08/20.