Train doors at rear M2 car were not proven closed. TC opened and closed once to clear fault. ~~~~~ Train doors at rear M2 car were not prov     Found FOD at #3520-A3 door and #2520-A1 & B1 door have higher resistance due to accumulation of dust.Lubricated the J-rail and cleaned.Door function tested ok. Done by Ong Ting Wei. 06/01/20