Hacking your Garmin

I wouldn’t call standalone GPS units “disposable”… but nowadays you can buy entry-level Garmin car units for as little as $89.99, and refurbished units can be had for as little as $59.95. This makes paying $49.99 for a map upgrade seem like a losing proposition. $50 didn’t seem like much back when a GPS cost $700. But now that you can buy a whole new (refurbished) unit for only $10 more than a map upgrade… why bother?

If you’re still rocking a Garmin GPS unit, you might not know that updating the maps for free is amazingly easy. I would never, ever recommend that you put an illegally hacked map on your GPS. But if you were the kind of person who isn’t opposed to that, all you need is some spare time, a computer, a Bittorrent client, a USB mini B cable and, most likely, a small (2 to 8GB) SD card. And although I would never, ever do this to my own GPS, I could, theoretically, report that Method 2, Part A on the linked page works like a charm on Nuvi 260W units. (see updates below)

Theoretically, of course.

Yeah, I have GPS on my smartphone. And it works well, too. But if I use my phone as a GPS driving aid, I can actually watch the battery drain. And I don’t have a windshield mount for my phone, either. So I’ll keep using the Garmin for the foreseeable future.

UPDATE (01/25/2016): I thought standalone GPS systems were all but dead, but looking at my site logs today I found that 20+ people visit this page every day. I decided to take a look at this article, and found that the haklabs page I linked to in an earlier version of this post is gone. So I thought I’d elaborate a bit for people who still need instructions.

The first thing you need to do is connect your GPS to your computer via USB cable and go to Garmin’s site. I actually recommend using Internet Explorer for this, because you’re going to need to install an ActiveX plug-in (Garmin’s site supports Chrome and Firefox, too, but you’ll need to restart those before continuing).

Create an account on Garmin’s site if you haven’t already. Then login to the site, attach your GPS to the USB cable and click the “Update” link. You will be prompted to install an ActiveX plug-in, which will search for your GPS and report its software and map version info to Garmin’s site.

See update below

UPDATE (09/07/2016): Thanks to jimcofer.com reader Joe, who pointed out that Garmin has retired their web browser plug-ins and has a new app you can use to update your unit: Garmin Express. So if you want to update your Garmin’s OS before updating the map – and you really should – click the link, download and install Garmin Express, connect the GPS to your computer via USB and start Express. Thanks, Joe! 🙂

UPDATE (02/24/2017): I just wanted to mention that the Garmin Express app comes with an auto-start feature. Unless you’re managing a fleet of cars and update Garmins constantly, there’s no reason to have Garmin Express start when your computer boots up. In modern version of Windows, you can disable this from starting by opening Task Manager (CTRL+SHIFT+ESC), clicking the Startup tab, and right-clicking on “Garmin Express Tray” and choosing “Disable”. For older versions of Windows, click Start > Run then type MSCONFIG and press ENTER.

Anyway, if there an update for your Garmin’s OS, go ahead and install it. Always install the software updates; they’re free and add new features and fix bugs. Also, if you have an old (very old) Garmin you’ve never updated, an update might enable support for SDHC cards, which is the format most SD cards use these days.

Next, you’ll need to go to a certain PIRATE website, located in a BAY of some sort, and search for “Garmin North America” (or “Garmin Europe”). You will get many results: look for the one with the most recent map; this is currently 2017.10 (Garmin names maps by year and version, so “2015.20” would be the second version released in 2015). Download the file as one normally would.

Once the file is downloaded, you have to decide what to do with it.

If you have an older Garmin, you likely won’t have enough storage space available to store it internally. If this is the case, insert the SD card into a card reader on your computer, format it as FAT32 (if necessary) and create a folder called “Garmin” in the root of the drive. Then copy the gmapsupp.img file into the Garmin folder. When that’s done, eject the card, put it in your GPS, turn it on, and go to Settings > Maps, where you can select the new map.

If your Garmin does have enough free space to hold the new map, you’re probably going to want to connect the GPS to your computer via USB and copy the existing “gmapprom.img” to your computer (it’s always good to have a backup). Next, delete the gmapprom.img file on your GPS, rename the downloaded gmapsupp.img file to gmapprom.img, and copy it to the same folder on your GPS. When that’s done, unplug the GPS, power-cycle it and make sure the map is correct.

Either method works if you have enough storage space. But I prefer the SD card method, as this is easily reversible, especially if you’re away from your computer: just turn the GPS off, remove the SD card from the GPS, and power it back on. The unit should default back to the previous (internal) map.

28 Replies to “Hacking your Garmin”

  1. hi jimcofer.com. I have tried to upgrade my garmin 255 and now I have NO MAPS ON MINE LEFT! used 64gb sdhc card and file downloaded was corrupted please help?

  2. Well, the first thing I’d do is try a smaller SD card. According to the link below, the largest SD card any Nuvi series will accept is 32GB (except the 295, 800, 805, 5000 series, which can only accept 8GB cards):

    https://support.garmin.com/support/searchSupport/case.faces?caseId=%7B18331ce0-4af6-11e3-f27b-000000000000%7D

    I use an 8GB card myself, and have never had a problem with it. I DID try an 8GB microSD card in an SD adapter once, but the Garmin didn’t like it much, So I ordered the 8GB off Amazon and have been good since.

    Aside from the SD card issue, the two most common problems with upgrading maps are making sure the name is correct (“gmapsupp.img” for SD cards, or “gmapprom.img” if stored internally). Also, if using an SD card, make sure it’s set up correctly: there should only be one folder in the root of the card (“Garmin”) and the gmapsupp.img file should be the only thing inside that folder. If you put the map file itself in the root of the card, it won’t work. And if you put the map file inside the “Garmin” folder, but give it the wrong name, it won’t work either.

    In any case, if you back up your original map, you should always be able to go back to what you had by copying the gmapprom.img file back to its original location on the unit, or simply removing the SD card and making sure the correct map is selected under Settings > Map.

  3. Hi, Jim. If I get the latest map from the bay, or a free map from OSM, and place it on the external storage media, the new map shows up in the menu system of my 2360. However, the latest map is not used. The effective map remains the old map. I can have both maps enabled. I can have the latest map enabled only. I can have all maps disabled. It makes no difference. The effective map remains the old map. Is there any solution to this?

  4. Have you tried copying the old map to your computer, then deleting the old map on your device? That way, the unit has no choice BUT to use the newer map? Whatever you do, though, make sure make a backup of your original map, so you don’t brick your device!

    I have to ask, though: I looked at Garmin’s site just now to see how old your device is (thinking maybe this is a “hack” that works on older models, but not newer ones). But Garmin’s site says that your GPS comes with “free lifetime map updates and traffic”… so why use a hacked IMG file at all?

  5. Hi Jim and thanks for your article. I have a Nuvi 1300 and when I go to Garmin it wants me to download Garmin Express. Is this what you mean or is there any other alternatives for the ActiveX plug-in? Thanks

  6. Wow! What timing! The missus and I rarely use our Garmin these days, preferring our phones for local trips. But we have a beach trip coming up in about a month, and I was just about to update the map on our Nuvi 265 when you posted your comment!

    Yes, it seems that Garmin has ditched their browser plug-ins for Garmin Express, a standalone app. FWIW, the app TAKES FOREVER to start on my system, but it upgraded the Nuvi’s OS without issue. It’s also kind of nice that the app retains your OS and map version info, so you don’t have to have the GPS connected to your computer to check for updates, as you did with the browser plug-ins.

    You might want to disable a few things in the settings. Under “General” the option to “always keep Garmin Express running in the background” is checked by default, so you might wanna uncheck it. On the “Schedule” tab, you might also wanna set the “download device updates” option to “Never”.

  7. Hi Jim, Followed all you upgrade points for nuvi 5000, firmware, 2016 NA map. Downloaded map to SD card inside Garmin folded named it gmapsupp.img and it appears that my GPS is not recognising my SD card. My SD card is a 8GB HDSC, have been playing around for days, Any help would be appreciated.

    1. Not sure what to tell you. The 5000 should have SDHC support built-in. Are you sure it not recognizing the card at all, verus not seeing the map on the card?

      1. I am not sure if it not reading (finding) the map on the SD card or it is just not reading the SD card. I tried another SD card with no avail. When I go to maps in the menu, it says there are no maps installed thus no box to tick.

  8. I thouoght it prudent to provide an update. While many people seem to think the software is clunky, it does work. My 1300LM is still kicking and in fact, I just updated to 2017 maps.
    Jim mentioned earlier about the death of phone battery on GPS. I also noticed that my phone almost needs a small water cooled radiator during live maps use. This limits things considerably.

    We have a standalone GPS in each vehicle and one to use in rental vehicles (I custom mount the GPS making swapping in or out not particularly easy but possible for updates). After installing the Express software and playing with it a bit I seem to have few issues. It compares device software revisions to the latest and will tell you if you need to update.

    What I don’t like is that it becomes resident by default and I have yet to find an easy way to have not start up automatically EVERY TIME. Since it only gets used a couple times per year, I see no reason to have it park itself as a resident on the computer.

    Has anyone found a way?

    1. In Windows 10, right-click the taskbar and choose “Task Manager”. When it opens, click the “Startup” tab, right-click the “Garmin Express Tray” entry and choose “Disable”.

      Not sure how it works in earlier versions of Windows. You used to be able to click Start > Run and type MSCONFIG and then ENTER and disable it there… but I’m not sure when MS got rid of that option.

  9. Hi Jim

    I loaded the NA maps, on the SD card no problem. But I also want the European maps. The particular Bay map I found instructed me to create the Garmin folder and call the NA file gmapprom.img.
    If I give it the same name as the NA map (gmapprom.img) to the European map and put it in the same folder, how will that work?
    Is there something I’m missing?
    I’m lost and need direction 😉

    1. It won’t. The file(s) need to have the same names, and you can’t have 2 files with the same name in the same folder. What you might be able to do (depending on how much space you have on your device) is copy the NA map to the internal storage and the Europe map to the SD card. That way you could go to Settings > Maps and choose which one you want to use. I’ve never tried that, but there’s no reason (in theory) why that won’t work.

  10. I’m not overly tech savvy and can find no guides to do this on a Mac. I have the files downloaded and ready to install but cannot see hidden files. Any assistance would be appreciated.

  11. To Don: I had some problems a few months ago trying to use a Mac to copy updated maps to a SD card. My Nuvi 200 just wouldn’t use those maps. Once I tried to do the same on a Pc, everything went as usual and worked as it should.

  12. Jim & Don – If you have sufficient room in your unit without having to use an SD card, name your second map gmapprom1.img
    Otherwise, on an SD card, rename the second map gmapsupp.img

  13. Jim & Don – If you have sufficient room in your unit without having to use an SD card, name your second map gmapprom1.img
    Otherwise, on an SD card, rename the second map gmapsupp.img

  14. Thanks Jim! I knew I could trust you as soon as I saw the “drinking whisky clear!” At the top of the screen.

  15. Man, I’ve tried everything and nothing works. I have a garmin gpsmap-64 and the new 2017 north america maps. I’ve renamed the files and even tried loading from the sd card. The only thing that I can get to work is the north american topo maps.I’ve even tried renaming the img-file to “gmapbmap.img” because that’s the original img file on the unit. I keep getting “Can’t Authenticate Maps”…There’s got to be a way to just combine this map with the topo map that works.

  16. Any chance you can direct me towards some information that would allow me to download my activity data from a Garmin 310xt WITHOUT having it go through Garmin web services? I’ve accessed route data in JSON format from Strava after it’s passed through Garmin’s web service Connect, but my question is how to access the data directly without using those web services. Thanks!

  17. I have older Garmen map that’s unlocked got it from bit torrent site works on all older gps units but won’t work on newer ones says can’t unlock maps why is this

  18. Just an FYI for everyone: against my expectations, an old Nüvi 205 supports a 64GB SDXC memory card, you just need to make sure it is formatted with Fat32 (Not NTFS, not exFat). Windows does not support formatting to Fat32 for memory cards over certain size (32GB?), so you might need an external tool for this. Something like MiniTool Partition Wizard works for this (there’s a free non-commercial version available). MPW is not the easiest tool, but there are probably other easier tools or methods as well, just do a quick google search.

    Thanks for this guide btw, works great! Old garmin navs are available for next to no money, so this is a good guide for those on a tight budget.

  19. Hi, I got old Garmin nuvi 5000 for 10 bucks and pay 50 bucks for map update… it’s crazy… I read your advises, they are very helpful, but I stuck on map update. I got unlocked update bu t my Nuvi 5000 don’t see it on SD card. This device can NOT see files bigger than 2 GB! ( … There are a lot of update files around but all of them over 2 GB. I read about GMap Tool, but I did not found any clear instructions how to split big file. Any clear advise how to split or compress an update bigger than 2 GB? Thanks )

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