Nothing to do with .sum files, they're checksum files made by the unit and you can delete any of them without harm.

Whay you do need for your unit is a different map. This version will run ok if you don't need to use Cyrillic script, but there is no JCV file issued for it compatible with xx series nuvis. The nuvi xx VCJ files are encrypted differently to the ones available in here which are only for nuvi xxx & xxxx series. If you want JCV, dl the Unicode version map and D3589100A.JCV from here: [Only registered and activated users can see links. ].