thanks for helping , that solution , i 've already tryed in the past unsuccessfully , the only way to restore bluetooth was to downgrade principal firmware ( not bluetooth firmware) to older version ( don't remember if it was to 4.6 , 4.7 or 4.8) ; so i am ok to try again now but (because of erasing all data on my device by mistake) i don't have the folder "remote sw" in my device , where sould be located the file to replace ( but in the root on the garmin device i see a file with the extension .GCD witch does not have the same name as the one that i must place on the device...) must i try ??

thanks for giving your opinion ( on my device there is not the folder "remote sw" , but in the garmin folder i see the file "GUPDATE.GCD" mus t i replace this one ??)