ECB activated at front DT car while departing YCK SB. Train unable to reset EB after operating ECBBS . TC confirmed no other fault indications. TC was instructedto reset ECB but cound not locate it. Operated DIRBS and DC  ~~~~~ Not a defect - CBTC applied EB due to 3546 B/side cab door not properly closed when TC was occupying cab.     Conducted function test, no abnormalities found. Re-adjusted 3546 B/side cab door latch to improve positive catch engagement (>6mm). Cleaned and lubricated the top door track and door guide for smooth cab operation. Done by Kumar/Jack/Sateesh/Koh. 05/03/20.