Carminat navcore 8.843 + maps 1025 problem

To clarify everything here's what I'd and why:

When I started making my SD card on tomtom version 8.843 as suggested by @cacou13 general-discussions-about-tomtom/carminat-tomtom-navcore-843-incompatible-map-patched-t21083.html
I patch everything with Fast Activate my carminat in the car says "you can't use this map in this device". Went back to pc and change in the ttgo.bif file by text editor the line current version to 8842 then use fast again after that I put the card back to carminat and was OK but device restarting every time when show map. Again I took the card back to PC and reverse the line ttgo.bif to 8843 and this carminat did not restart and I discovered that the map refresh was very slow. The problem like this is in 99% of time that the SD card is faulty even if pc not indicate that (reading of card is slow) I've change the card for new and is working perfect.

Thank you @holyhead and @cacou13 for show me the way how to do that and push me (only figuratively) to start think a little bit not just asking

Yes, I confirm the procedure of “Cacou13” work well.
Navcore 8.843 upgraded on car from Tomtomhome
rebuilded the new sd card with instruction of “Cacou”
inserted and activated new maps (on my case Italia_1025_9389)
added the voice, velox, and voilà.
Any other tricks are required.

Thank a lot Cacou!

works perfect !