Problem : I have problem with a damaged BSI (com to dashboard) so I have changed it with a new(used) BSI unit (now I have immobilizer problem against ECU, won't start)
Question : What matched components do I need to replace for normal function of the car ?
I know that I needs matched BSI - ECU - KEY, but do I have to replace the PSA calculateur and ABS unit ?

I would be grateful for an answer

Kind reg.
Rune S. - Norway