Key Fob 1 not responding

Hi all.
Had my P38 just over a week now and so far, so good.
Remote Fob 2 works fine, remote fob 1 had buttons missing and wasn't working, so fitted new button cover, battery cover, and fitted new batteries.
Now when I press a button the led flashes, great it works !!!
Have tried to synch it to the car but no deal. It is a late 1999 Thor engine type and the handbook says to synch the key just put it in the ignition. Have tried that but so far no good.
Is there some special thing I am not doing or is the remote fob f****d ??????
Your help would be greatly appreciated

Did you try turning the key in the ignition to position 2 then back to position 0 then try starting the car??

I recently disconnected the battery in my '99 DSE and I put the key in the ignition, turned to pos 2 then 0 then started vehicle fine....but to lock the car, I had to lock the doors with the key, then unlock with the key, then lock with button then unlock with button....

Not sure why I had to do the unlock thing as the book didn't mention it, but it wouldn't lock/unlock until I tried the key in the door....

It may help..!!!

Thanks SaintV8,

Did as you suggested, turn ign to 2, waited 30 secs, turned off. Car started and now locks and unlocks the doors.
Many thanks for your help.

Pleasure....glad it worked.