Train doors at rear DT car A4 door werenot proven closed. TC recycled train doors a few times - ok.Fault did not recur at subsequent stations. ~~~~~ 3627 Train A4 doors were not proven closed. TC recycled train doors a few times - ok. Fault did not recur at subsequent stations.  (L3)  3627 checked/found A4 door sensing s/w out of alignment. Adjusted the door sensing s/w. Security check & Push/pull test - OK. Door cyclic test - OK.     Lee PT/Shafie 44524