TC reported train doors at RM2 car werenot proven closed.TC manually open and close doors once - OK . TC reported at FM1 car 'A1' door not proven closed again a t AMK2. TC open and closed doors to no avail. Pax disembarke ~~~~~ TC reported train doors at RM2 car were L3  Downloaded ER and fault trace on PTU006.From fault trace observed #1612 A1 door detected obstacle.Door unable to fully open but door encoder able to capture current for door to open. Checked door operator,DCP,door rollers and weather strip,ok.Checked door guide rail and J-rail no F.O.D.observed. Serviced door rollers and J-rail ok.Checked DCP connectors for oxidation and continuity check ok.Carried out door cyclic/function test ok. Checked by Joshua. 17/05/20