Garmin Nuvis can be handy GPS systems, but they are limited in memory. If you are unsuccessful in downloading updates, deleting any unused pictures or language files may help free up the needed space to complete the download.
Plug your Garmin Nuvi into your computer using a standard mini USB-to-USB cable.
Locate "My Computer" on your desktop and double-click on the icon. Locate the Garmin Drive and double-click it to open it.
Double-click on the Garmin Folder. This will open the following folders: Text, Help, Voice, JPEG and Vehicles. Double-click one of the folders.
Delete any unused files of languages, pictures or vehicles. Do not delete the language you use for your Garmin Nuvi.
Locate the Garmin Drive on your computer and double-click it again, opening the folders in the drive.
Repeat steps 3 to 4 in the other folders listed until you have deleted everything you can, and then try to run your update again. If you have freed up enough memory, the update should work now.
The updates must be downloaded into the internal memory of your Garmin Nuvi system, so adding them to your SD card will not effectively update your Nuvi.