C3, 2002, 1.4Petrolkfv - Bsi-Ecu-Key-Psa(Powersteering)-Abs

[runsun]

Hi !

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 ? http://citroenc3owners.com/images/smilies/icon_question.gif 

I would be grateful for an answer http://citroenc3owners.com/images/smilies/icon_cool.gif 

Kind reg. 
Rune S. - Norway