...I want to copy my immo info and write it to a spare ECU .
what ecu? what car?
vw/audi "Immo info" is typically stored in more places than just the ecu, and according to which immo system you have, it may only be stored in the cluster.
The type of ecu will dictate the available methods of reading and writing.
I highly suggest reading through the cluster-&-immobilizer stickies, as well as getting more familiar with the inner workings of the eeproms of your ECU. 95040, 24c02, am29f[X]00BB, and others are well covered here on this forum.
-Cyril
