CENTRAL LOCKING FOB?

I HAVE RECENTLY HAD CAM BELT CHANGED AS OLD ONE SNAPPED (BUGGER), SO BATTERY OFF AND THAT BUT MY REMOTE KEY FOB NEEDS RE-SYCNING, TRYED KEY IN IGNITION AND TURNED TOO 2 POSTION AND PUSHED LOCK AND UNLOCK BUTTONS BUT NOTHING, LED INDICATOR ILLUMINATES EVERY SO OFTEN WHEN BUTTONS ARE PUSHED, I HAVE REPLACED BATTERIES WITH SEVERAL DIFFERENT TYPES AND CHECKED FUSES BUT NO APPARENT PROBLEMS, PLEASE HELP.