Try the Sony remote control forum. That is really for Sony's programmable and learning remotes, but chances are good that someone's expertise will shine and you will have an answer pronto. No pun intended.

Also, you seem to be asking about something that should just plain work. It might help if you went into more detail. Why are you specifying RC16? Is that a remote control model or a remote control code? (RC code)

What have you done that the original remote needs to be reprogrammed with the original codes...seems it would have them. Or that it needs to be UNprogrammed, which is basically RESET. Have you searched the Sony site for an instruction manual for the receiver or remote, in case you don't have them, to find out how to do a reset on the remote? I think if a remote USED to (you don't say it EVER did) control the volume but does not now, a reset would fix it.