TC reported train doors at rear DT car was not proven closed. TC opened and closed train doors once to clear fault. ~~~~~ 3630 TC reported train doors was not proven closed. TC opened and closed train doors once to clear fault.  TIMs Shows 3630 A4 door not proven closed. Checked door guide & weather strip - OK. Door mechanism checked - OK. No FOD found. Performed door resistance check = 4.0 kgf. Cleaned J-rail as preventive measure. Door operation check - OK.     AU TK 44398