Thread: MapUpdate uses SD card for essential files

Recently did an update on a unit with not enough internal storage. Have read this but could not find more info.

Originally Posted by Strephon Alkhalikoi

Garmin recently revised their map installer to take SD/MicroSD cards into account.

Spoiler: CLICK

Your device does not have enough space for Full Coverage of …. Please choose an option Insert an SD card into my device -or- View alternative install options.

If you choose to use an SD card you get the note

A note about this SD card. Essential files will be stored on the SD card. After installing the map update, you must leave the SD card in your device or it will not function properly.

MapUpdate then installs the additional files [JCV, ASR, sid, etc.] internal and the map file on SD. GMAPPROM.IMG GMAPPROM.unl GMAPPROM.gma are in the folder [SD]:\Garmin\ on SD card with a new file gmappupdate.gsd of 0kB. There is no content in the file but if you remove it the map does not function, conclusion: gmappupdate.gsd triggers the firmware to use the map on the SD card. Normally [SD]:\Garmin\gmapprom.img does not function, only gmapsupp.img. 2th conclusion: This construction makes it possible to split the map file from the additional files. We need more experience from other users with advanced models [probably only nuvi 2xxx and 3xxx] if this is useful for tweaking [basic models don’t use additional files or only 3D and JCV files and those will function if you put them all on the SD card] Tested on nuvi 2595 fw6.30 with mapupdater_v3.0.11. Don't know if other files are put on SD card if there is not enough space for all aditional files and if they function properly.