Change the name of gmapprom.img in main memory & move it to SD card.

Started by MAMOUTHEN, January 16, 2011, 05:36:37 AM

Previous topic - Next topic


I have my garmin main memory become almost full. I plan to change the name of the preload map (Navigator Europe NT v9 Limited- Deluxe) gmapprom.img (1.35GB) and gmapprom.sum (1 KB) in H:\Garmin\ to gmapsupp.img & gmapsupp.sum. Then after that I will move both files to SD card (I:\Garmin\).

The Idea is that to make extra space in the main memory for the new update for my essential map City Navigator Middle East NT 2011 in H:\Garmin.

1st question do you think it will work out.

2nd After this operation I will have in my SD card I:\Garmin\ gmapsupp.img only (which was originally gmapprom.img in main memory), and gmapprom.sum left in main memory H:\Garmin\.

1. Shall I leave the gmapprom.sum in the main memory without any change.
2. Shall I change the name of gmapprom.sum in the main memory to gmapsupp.sum and then move it to SD card to make sure that the moved gmapsupp.img (originally gmapprom.img).  :)


You haven't told us what model GPS you have. I assume it's a Nuvi? Be very care with this! When the Nuvi starts up, it looks for gmapprom.img. If it isn't in main memory, the unit will not start up and it won't work - it will display an error message something like "No detailed maps found".

As I understand it, gmapprom.sum isn't needed at all. It contains a checksum that is used to verify the map when it is first installed, and after that it is not used. There may be a file named gmapprom.unl however that contains your unlock code and it will be needed.

So if you are going to change the name of gmapprom.img and move it to a memory card, you had better replace it with another file named gmapprom.img or your unit will no longer work.


If it is a Nuvi, then there is a lot of stuff you can take off to free up space. The languages you don't use, the other voices you don't use, can be transfered to your PC with no harm done.

If this is the case, then go look at the POI Factory and do a couple of searches about freeing up space on your Nuvi.


Thank you guys for your quick replys. :)
Sorry did not mention my GPS, it is Garmin 250W.

I have changed the name of the preload map (Navigator Europe NT v9 Limited- Deluxe) gmapprom.img (1.35GB) to gmapsupp.img and then move it from main memory to SD card of my garmin. The gmapprom.sum (1 KB) in main memory (H:\Garmin) was left as it is.

Then I have changed the name of the existing gmapsupp.img for the map City Navigator Middle East NT 2011 in the main memory to gmapprom.img as to your advice.

So far everything is working perfect with City Navigator Middle East NT 2011 which is in the main memory and its name changed to gmapprom.img now, It is for the area where I leave now.
For the  preload map of Navigator Europe NT v9 Limited- Deluxe which is in the SD card now with gmapsupp.img name, I went though it from the device menu itself and found it available, I cant make sure it is working perfectly as I'm not in the Europe now.


I think this will all work fine for you. You can test it by using the GPS simulator. Press Menu > Tools > Settings > System > GPS Simulator > On.

Now zoom way out, drag the map to Europe, then zoom back in on a location of interest. Press the "Sec Loc" button at the bottom of the screen. Now your Nuvi will act like it really is in Europe.


I have used the GPS simulator. I dragged the map to Europe, select one location and pressed the "Set Lo" then I moved the crosser to another location (nearby) and pressed "Go!". The simulator worked properly and everything seems to be fine.

After that I have put my car back in UAE – Abu Dhabi (within City Navigator Middle East NT 2011 coverage map) and pressed the "Set Lo" then I have dragged the map to Europe, select one location in London and pressed "Go!"
I have received the following message:
Unable to Calculate route:
Not enough memory available

Then I re-select another location in Europe – Germany and simulator start working.

I found that when the distance between two points is more that 1500 KM the above message will come. In the first case the distance between Abu Dhabi and London around 5000 KM, but in the second case the distance (Abu Dhabi – Germany) was 1500 KM.
Note: I have in my garmin main memory 1.24 GB free space.


You are misinterpreting that message. "Memory" is what we usually call the flash drive where the maps are installed, but this is not really the correct word. In computer terms, that is "mass storage" - it's treated like a hard disk on your computer.

The real "memory" is RAM - high speed random access memory, like the SIMM's in your computer. This is what's used for calculations. It's typically very small, especially on an old model like yours. There's probably only 64MB of memory on your Nuvi, maybe 128MB total. There is no way for you to know how much of it is in use.

So it's running out of this RAM memory when calculating your route, and there's nothing you can do about it except break the route into smaller pieces.


You have to realize you are dealing with a low end VEHICLE GPS. A route of 900 miles is not reasonable for a vehicle in normal terms.

You may be able to drive 900 miles in one trip, but that is not a normal trip. If you break the route up into no more than 600 mile routes you should be fine.

Also according to Garmin the 200 series doesn't do routes created in MapSource or BaseCamp.


In fact I have done this test just to make sure that the preload map which has been moved from garmin mass storage to SD card is going to work properly when I go London next summer. I agree alpine A route of 900 miles is not reasonable for a vehicle & driver.

I'm happy to know that the message I have received it's because of garmin 250W specification, and not because of my preload map movement.

Thank you for your time and very nice explanation. 
:) :)


Maybe it's just the Garmin Nuvi 200 series (?) but my 350W (not the newest GPS in the world) and I mapped a route from Massachusetts to Arizona with no problems.  2500 miles (4000 km)


The OP was creating a route that spanned across two different map products. I suspect that may have something to do with the error...