TIMS showed BCU intermittent fault at front M2 car. Since AMK2. Train performance - ok. ~~~~~ TIMS showed BCU intermittent fault at fr     #2534 Check and found ACU exhaust air leak while applying brake.Replaced ACU and function test & brake cycle test ok.ACU swapped from car #1552 due to fault was intermitten.To be further monitor from M/L service. ACU- Old s/n: 1042-070 New s/n: 1020/003 Done by Yusof/Rizman/Zul/Haikel. 16/01/22