Train stopped with BCU/BCP fault, bogey1 and bogey 2 at car 2611 after departing BGB B. STBS operat ed. Pax disembarked at CCK B. ~~~~~ L3 2611 D/L ER & found signs of BCU fault. Replaced BCU but fault still persisted. (reinstalled the old BCU & set wheel diameter at 833mm). Brake pressure remains at 3 bars at COAST/B1/B2/B3 positions. Replaced ACU & function check - OK. Limited movement/depot shunting - OK. #2611 ACU S/N : OLD : 1549/214. NEW : 1434/022. #2611 BCU S/N : OLD : 1517/177. NEW : 18303132.  Sarma/Wong/Anand/Rasul/Kiran. 09/05/2021.