Update Garmin Nuvi Maps for Free!

No you don’t have to have either Windows or Mac in order to update your Garmin Nuvi GPS (or Magellan, TomTom, and a few others). And no, you don’t have to pay for updated maps either, even if your GPS is older or unregistered with the company.

I did it, and I’m still as technophobic as I ever was. So if this li’l technophobic sidekick can manage it, it’s likely that any of my readers can. I do the FedEx Ground delivery driver thing, and I have an old hand-me-down Garmin Nuvi that I use on my route. Not for directions, but just as a “rolling map” to tell me where I am and streets are coming up as I travel.

The technique I’ll show you here uses OpenStreetMap, a free and open-source collaborative work. Maps are updated much more often than the official Garmin maps. They also show considerably more detail, judging by my Nuvi’s performance today. I’m just going to write about the Garmin GPS because that’s what I have and all I really know. But according to this wonderful web page, it also works for some other brands.

I navigated to my /home directory and created a new folder named “GarminNuvi.” It has a subfolder called Maps.

I connected my Garmin Nuvi to my computer via a USB port and it was automagically mounted, thanks to Thunar’s awesomeness (Thunar is the Xfce file manager in Linux). I then copied the map file, named gmapprom.img, to /home/robin/GarminNuvi/Map. You can do this in the terminal or just open your file manager as root (“sudo thunar” in a terminal window) and move the file from your Garmin to the “Map” subfolder. This is a safety thing! ALWAYS BACK UP the old map in case something goes wrong! Now you can DELETE gmapprom.img from the Garmin. I renamed this backup file gmapprom-old.img. If I needed to restore it, I’d give it back it’s original name.

Select and download the new maps from http://garmin.openstreetmap.nl/ It’s easy, just follow the prompts on the screen to select your map by continent, country, state, province, or customize your own. If you customize yours, you’ll need to enter your e-mail address and they’ll notify you when it’s compiled and ready to download. My old map is North America, nearly 3GB in size! Yikes! So I selected only my own state for the new map, because that’s really all I need and it’s just a few hundred MB in size. Easy peasy. And fast! The file you want for the Garmin Nuvi is named osm_generic_gmapsupp.zip.

Move that file to /Garmin/New and extract it there. 7-zip works, most default "archivers" work for decompressing zip files. After unzipping it, you'll have a file called gmapsupp.img. For the Garmin, you must rename that file to gmapprom.img. This is your new map! Copy it back to your Garmin, re-start it, and take it for a test drive.

Save a copy of your new gmapprom.img in the /Garmin/New folder as the next backup. When it's time, that can be moved to the Old subfolder. But until you're sure everything works okay, keep that old one around!