Garmin GPS systems are great if you don’t know how to find your way to an address but their maps often get outdated in a few years as new infrastructure is developed in your city. Many find the $80 update somewhat of a pinch in their pockets so here is a solution for those people!
Using this guide you will be able to update your Garmin GPS system to the latest (2010) map data, all you need is a little bit of patience and careful reading.
The 2011 Map Guide is now up.
What will you need?
- Garmin City Navigator 2010.40 (Method 1) OR 2010.40 Unlocked IMG File (Method 2)
- Garmin MapSource v6.15.7 & MapInstall v3.13.2
- Garmin Unlocker (available here)
- A Garmin GPS device plugged into your PC
Method 1 (Mapsource Install Instructions)
1) Run the setup file named “CNNANT2010Update_ENU.msi” from the “IMG” folder in your downloaded city navigator files.
2) Install the Garmin Mapsource software on your computer.
Note: The 2010.40 update also updates the version of MapInstall on your pc to v3.13.3. Before moving forward, downgrade to v3.13.2 using the following instructions:
- Remove all Mapinstall files the from the Garmin install directory (mostly located at C:\Garmin)
- Download Mapinstall v3.13.2 from the links provided & run the installer
- Launch Mapinstall and sync to device
3) Once the software in step 1 and 2 are installed, run the program named Mapsource from Start > All Programs > Garmin. Mapsource will show you a prompt upon launching it asking to unlock the maps, close this prompt window using the red X on the top right corner.
4) Now click on Utilities > Get Unit ID from the menu bar. The program will take a second and display your device’s unit ID (make sure your GPS is plugged into your computer to get this). Copy this unit # number and write it down elsewhere as a safe measure. Once you have the number written down, close this window.
5) Leave Mapsource running (minimize it) and open the Garmin unlocker you downloaded from the link provided before. Put the Unit ID code you wrote down in step 4 in the top most box of the garmin unlocker thats says “Enter your Unit ID here”.
6) Next, in the ‘Select Map Product‘ field select the last option of ‘custom maps’ and enter 450 when prompted and hit OK. If using the City Navigator North America 2010.20 maps enter 2005. If using the City Navigator North America 2010.30 maps enter 2051. If using the City Navigator North America 2010.40 maps enter 2201.

7) Now click on the Generate button located on the bottom of the window next to the Exit button. This will give you the unlock code, copy this code and keep it somewhere accessible. You can exit out of the unlocker now, its work is done.
8 ) Go back to the Mapsource window and from the Utilities menu and select Manage Map Products. Now click the ‘Unlock Regions’ Tab and press the ‘Add’ button. Paste the code you got in step 7 into the ‘Add Unlock Region’ dialog box’s first field, the second field is optional. Hit OK and you have unlocked the map product.

Now you can close Mapsource.
Note: Before moving foward, navigate to the Garmin folder on your device. An icon for your device will be under My Computer. In the Garmin folder you will find a file named “gmapprom”. Backup this file and then delete it from the Garmin device. If you cannot find the exact same file name, look for the biggest file in that folder (it can be anywhere from 500 MB – 1GB).
Now launch MapInstall from Programs > Garmin
9) Mapinstall will ask you for the regions on the map you want to install, choose your desired regions, hit next and then press Finish.
Depending on the amount of map data you choose to put on, the maps will transfer to your device between 30 mins – 1 hour. Once completed you will have the new 2010 maps on your GPS system, you can also check the maps version on your device via Settings > Maps > Map Info.
Method 2 (Unlocked IMG Instructions)
1. Connect your device to the computer.
2. Go into the Nuvi files and backup the file named “gmapprom.img” to your computer.
3. Delete the “gmapprom.img” file from the device.
4. Copy the unlocked “gmapprom.img” file that you downloaded into the device.
5. Restart your device and check your map info.
Having trouble with unlocking maps? Even with the right Mapsource version?
Mapsource might be causing an issue on your machine.
We have a fix for this :
- Navigate to your garmin installation directory (C:/Garmin/)
- Locate the Mapsource.exe file and rename it to MapsourceOLD.exe
- Download this replacement file, extract the contents and put it in the (C:/garmin) directory
The unlock code should now be accepted.
Want 3D map Data?
The 2010.40 3D Map Data can be found here
Simply drop that file onto your device memory or external memory and your 3D data should be loaded.
Enjoy the savings & drop us a line if you found this helpful. [donate]

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