TC reported TIMS indicated brake fault at Rear M1 car PWM fault with train decelerating intermittent ly.Brake status check performed - no fault found. TC repor ted TIMS indicated brake fault at Rear M1 car PWM fault with ~~~~~ 1649 TC reported TIMS indicated brake fault train decelerating intermittently. Brake status check performed - no fault found. CE: 3650 No Recurrence Of brake fault during monitoring ML3 1649 FC 309 Registered. BCP ER abnormal. Brake cyclic test - OK. Checked for brake application & release - OK. No brake fault registered. Opr 20 raised to check BCU connection and to replace BCU.    Chan SW 44918 1649 BCU Replaced. Brake cyclic test - OK. Old: 1446-069 New: 1509-158 Lee PT/Anand 44918 To follow up and rectify  1649 FC 309 registered. Replaced BCU & Tested operation - OK. Old: 1446/069 New: 1509/158 Lee PT/Anand 44918