I was finally able to update my RHB 430N past CNNT 2014.40 on my 2012. It involved purchasing an updated map through chryslergroup.navigation.com, but it works. If your RHB is eligible for an update through that web site, they will also send you a system software update. It's a new firmware version that I haven't seen anywhere before - 33.02.01. I was starting from firmware version 50.00.07, and here's the full process I went through...
1. Insert the USB stick with the 33.02.01 software update and say YES to update HDD files.
2. When promted to update Garmin software to 3.0, say YES. This will fail with the dreaded 'PND Update Failed' message, but don't worry, we'll get past this later. NOTE - I'm assuming this failed because I was coming from 50.00.07. This may work first time if you're starting from 23.04.41 or 33.01.23. If it does, you can skip steps 7-9.
3. Update application software to 33.02.01, say YES.
4. System reboot.
5. Application and Audio software are flashed.
6. System reboot.
Keep the USB stick plugged in!
7. When prompted to update HDD files, say NO.
8. When promted to updated Garmin software to 3.0, say YES. This time the Garmin update will succeed and your system will be at version 3.0.
9. Confirm both software versions are at 33.02.01 and say NO.
Your system should now be at 33.02.01 with Garmin Software Version 3.0. You can verify by going into Nav->System->About and viewing Software Version in the upper right corner. I think this is the critical step - getting to version 3.0. If you look at newer Garmin maps in Base Camp and do Get Info, it mentions needing Software Version 3.0 and above.
Now time for the map update. If you purchase the update through chryslergroup.navigation.com, they'll send 2014.40. I had already been at 2014.40 and I had a version of 2016.10 that I wanted to use. I assume the same would also work for the 2015.XX maps as well, but I did not test that. The Garmin update card that arrived had the following layout...
This varied from layouts I had used in the past which just had the gmapprom.img and JCV folder/file under the main Garmin folder. Because updating beyond 2014.40 had always previously resulted in an error message saying 'map not compatible', I was working under the assumption that maybe some of these additional files might be necessary. Maybe they changed the basemap and newer maps were incompatible, I don't know. But playing safe, I copied all these files onto my USB stick. Then overwrote gmapprom.img and JCV with those for 2016.10. I don't know if this ultimately mattered, and I don't want to spend another 2hrs testing with just the base files to find out, but I did and it worked and I'm not messing with it now. If someone wants to try and that works for them, yay.
10. Start car and insert your USB stick with 2016.10.
11. Map update detected, say YES to update.
12. Wait about 75 minutes for the update to finish.
13. You'll get a message that PND Update Complete
14. You'll then get a message that the maps failed to update, but if you actually check the maps in Nav->Maps->Info the update took.
So there you have it RHB owners - finally past 2014.40!
This thread is not to tell people how to get 2015 and 2016 maps nor how they can be unlocked. If you want to go that route, Google can help. But I can tell you that with the software update available through navigation.com you can get past 2014.40.
Now I need to deliberate moving back to 50.00.07 to get the nicer color scheme. Hope this helps. Good luck...