Large JVC files from Garmin directly
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    15 years
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I have often wondered why ppl keep uploading the large JVC file to mega.nv for others to download instead of just posting where they got them from. So, I asked COPILOT - where to download the garmin Large JCV Files? - Simple....
To get them officially, use Garmin Express, choose "install files to device and computer," and find the hidden files in
C:ProgramDataGarminCoreServiceDownloadsMap.....
As you drill down past that, there are 3 files at the end of each path.
For the current update: ACCORDING TO COPILOT == (please read to the end)
D224800B.img (@ 608,976KB under 'fusionna")
= North America DEM / Junction View
= Found in zūmo XT and other devices with full CN NA NT maps. Large file (~600 MB+) supporting detailed lane guidance.
D9644110A.img (@ 1,207,584KB under "na"... "img"..."006-d9644-11"...)
= Junction View for U.S.-only maps
= Part of Garmin’s split map update (2025.20 and similar). Covers United States only with full JCV images.
D9643110A.img (@ 3,661,056KB under "na"... "img"..."006-d9643-11"...)
= Junction View for Canada/Mexico maps
= Companion file to D9644110A. Provides JCV coverage for Canada and Mexico.
Why Multiple Files Exist?
- Device compatibility: Some Garmin units can’t handle the largest “full” JCV file, so Garmin distributes multiple versions.
- Regional split: To reduce file size and improve performance, Garmin separates JCV data into U.S. vs. Canada/Mexico.
SO, according to this, the LARGE file is NOT the one to use in the USA.
If you drive all of NA, then you have to install BOTH D964... files.
COPILOT:
Interpreting the three files
- D224800B.img (smallest) → Likely a “lite” JCV or DEM-support file, minimal coverage.
- D9644110.img (middle) → U.S. junction views, compressed for efficiency.
- D9643110.img (largest) → Canada/Mexico junction views, bundled together with higher-resolution images.
Why would the Canada + Mexico file be the largest according to COPILOT = because you can't trust COPILOT.
The truth is, according to a search using my browser, checking the file headers then challenging COPILOT:
COPILOT's response:
You’re absolutely right, Bill — thanks for catching that. Let’s lock this down cleanly so there’s no more ambiguity:
???? Correct Mapping (per the IMG headers)
• D224800B.img → Smaller “lite” JCV/DEM-support file.
• D9644110A.img → Canada & Mexico Junction View coverage.
• D9643110A.img → United States Junction View coverage.
Now you know.........
AI response is garbage
The entire reason people have to download the large JCV file from third party sources is because Garmin themselves only make it available to one or two devices. Everyone else with a device that uses full-screen junction view files, for example the nüvi 1350LMT and nüvi 3760LMT, gets nothing at all. Even the tiny 25-30MB file Garmin used to send to the 1100-1400 series units is no longer available.
The JCV files are pulled from HarryAR's device, which is one of those that still gets the largest version of the full-screen junction view file. He then uploads it and makes it available.
"Anyone who is capable of getting themselves made President should on no account be allowed to do the job." --Douglas Adams
Re: AI response is garbage
My favorite AI factoid supplied to a student was that 3.15 is larger than 3.9 [or some similar two numbers as I can't remember which two numbers were asked of the AI several months ago] because 15 is larger than 9.
When the question about the Large JCV was posed to AI:
I asked COPILOT - where to download the garmin Large JCV Files? - Simple....,
as far as I know, the phrase "Large JCV file" was invented here at the POI Factory and likely is not used anywhere else on the global web so AI possibly ignored the specific request's inclusion of the word large in the question.
Another concern that AI was attempting to answer a question above its pay grade, is that the DXXXX file names offered are not for the current City Navigator map, and the needed D filenames should end with .jcv, not .img, which Garmin probably reserves only for map files.
Asking copilot
I wondered what Copilot would answer to the question "What is the Garmin Large JCV file?"
The first answer is pretty good with one exception:
The Garmin “large JCV file” is a high‑resolution Junction View file that provides detailed photo‑realistic images of highway junctions, exits, and lane guidance during navigation. It’s essentially the biggest version of Garmin’s Junction View (JCV) database, containing more images and higher quality than the smaller or “lite” JCV files that some devices receive.
What Copilot is missing is that in "POIFactory-speak," the Large JCV file presents a fullscreen image of the junction view, which is used by older Garmin GPS models. Copilot does hedge their bet by saying "that some devices receive."
This brings up another question. In the POI Factory, the Large POI file is always a file for City Navigator North America. I wonder if a similar situation resulted in Garmin's European and other non-North America maps. Does anyone know if the same situation arose in these non-NA maps?
Large JVC files from Garmin directly
This is some very interesting info. I never knew Garmin itself makes the Large JCV files available. It's a Treasure Hunt. You have to know they even exist there in order to look for them.
Thanks for all of the other info about JCV files as well.