DT557: TAP2 UNDERSHOOT 1043hrs, 1323hrs,Analyse RS logs observed car 3558 Average of Brake Cylinder Pressure abnormal comparred to other cars Please check Brake system.Thank you ~~~~~ 3557: TAP2 UNDERSHOOT 1043hrs, 1323hrs, Signal Refer to RSD: 3558 Average of Brake Cylinder Pressure abnormal.  3558 found brake cylinder pressure abnormal,on high side. Replaced BCU & swapped ASP Transmitter from #3558 to #1558.    Brake function check - OK. Brake pressure within criteria. Wheel diameter set to 850mm. Limited movement/depot shunting, brake application checked - OK. #3558 BCU S/N : OLD : 1810076 NEW : 1809055  Farid/Haiqal 44278