Technical Key fob issue

[pauly boi 1989]

Hi all, firstly the story of my problem, car failed to start due to engine ecu failure, replaced ecu and bcm from another car and now its running perfect again, with changing this i now have no central locking from the fob (it works when inserting the key) hand new key programmed but still nothing, today replaced the bcm back to the old one and the old key fob works but obviously i cant start the car as they are not coded to each other, i do have multiscan but i cant see anything that will let me select remote locking on the bcm is there something im missing, part numbers are the same on bcm and same age vehicle. Thanks in advance