Train Doors at Rear DT A2 and A4 side not proven closed. TC opened and closed train doors a few time s to clear fault. ~~~~~ #3627 Checked FC,A4 door CLE.A2 door no fault code.Function check A2 door ok.Operation is smooth,no F.O.D. at door guide rail.Checked A4 door found L.H.S.door mating strip rubber obstructing door operation.Further found sticky substance at door guide rail causing door high resistance.Trimmed rubber strip and cleaned off the sticky substance-ok.Serviced door rollers and J-rail-ok.Swapped #3627-A4 door DCP to B4 door for further monitoring.Doors function test ok. Done by Kumar/Jack/Sateesh/Koh. 17/05/20