Can these security systems be transfered from bike to bike?
 

The alarm/siren module could be transferred, just unplug it. I changed mine.

But I think the key fob and immobiliser system would be a lot more difficult.

Why would you want to?

Thank you for your response.

I would like to take the HD security system of the bike I am selling and install it into the bike I am keeping.

Not all TSSM are the same as there year and model relevant. If there from different year or model you need to check part numbers.