TIMS showed 'A3' train doors at the front DT car were not proven closed. TC opened and closed train doors and HHPSDs once - ok. Staff (KTB) checked and confirme d that front DT car, 'A3' door was slow in closing and assis ~~~~~ #3643-A3 door fault code 063 & 066. Check A3 door mating strip distance 62mm, adjusted to 63.5mm. Door leaves when pulling to close door 5.8 to 6kg after cleaning guide rail and J-rail. Check guide rail no foreign object. Check door locking device function ok. Check and adjusted the locking s/w. Carried out door cyclic test ok. 20mm gauge tested ok. Door timing static test 3.4 sec open/close. Done by Din/Koh/Zulq/Joshua.  24/08/20.