Question about Nuvi 255

Hey guys!

I have a nuvi 255 (not the 255w). I paid 75$ sometime April-ish 2009 on a newegg sale and now it is pestering my wife to upgrade the maps on it. Garmin wants 50$ for a map update. (BTW the update price being 2/3rds the device is absurd) >:o

I read a blog posting a while back about someone who was able to use open street maps as a replacement on their GPS. I have found, downloaded, and have been toying around with mkgmap but I am a little hesitant in actually trying to import maps because I haven’t found a confirmation that it will work with the 255. Even though the maps may be out of date (and annoys us about that fact when we start it) the GPS still works. Since my wife uses it pretty regularly (work related traveling) I would hate to break it.

I must admit that I am tempted to just tinker with the 255 and see what I can do to hack it simply because if I screw it up I can get a new TomTom from newegg for 80$ which beats paying for the 50$ map update. :slight_smile: Plus I have never done any tinkering with maps or a GPS before so I think it might be a fun project.

Anyway, I was hoping that maybe someone could confirm if I can use the open street maps with the 255. Will it work? Will I lose any features? Would it just be better to get the TomTom for my wife before I wreak havoc on the 255? Or is this a waste of time for the 255?

Thanks! I appreciate the information!


If you are in the US and have an external micro SD card, you can download the latest OSM map for your area from . Those maps are large, but are convenient because they cover a large area. You can also download your area from to an SD card to see how it works.

The advantage to the OSM maps is that you get current maps. The disadvantage is that roads in many areas have not been created or verified. And addresses cannot be entered in the traditional garmin method, therefor many addresses will not be as accurate as the old Garmin original map.

I never got this message on my nuvi, maybe because I’m tinkering with it a lot. So I’m not able to give you a verified solution, but some suggestions. First of all make full backup of your nuvi. Simply connect nuvi to PC and copy all content to PC. It will take a lot of time, but you will have all files just in case.

  • Try to make reset. When in off state press and hold lower right corner of the screen, then turn on nuvi. Hold till the question about reseting user data, then confirm. You will loose all your setings and favorites with this operation.

  • Try program GMapTool. Open your map (file \Garmin\gmapprom.img in nuvi) with GMapTool, go to “Options” tab and set “Advanced options”. Then go to “Write” tab, check “Refresh header date” and press “Write all”.

Please report if any of this actions removes nagging messages. I’d really like to know :wink:

Hey guys!
Thank you very much for the information.
Sorry for the long wait time on my part. Some things came up and chewed up all my time (I was supposed to have this week to my projects and hobbies but RL had other plans :-/).

“If you are in the US and have an external micro SD card, you can download the latest OSM map for your area”
I am, and I have a micro SD. I will give this a try soon.

“And addresses cannot be entered in the traditional garmin method,”
So then this is probably something that will be fine for me to tinker with but maybe not so much something my wife wants to deal with (since she uses it for work)?

“I never got this message on my nuvi”
It isn’t every time we turn it on, but it comes up enough that it is annoying. I have started the backup and if I have time after dinner I will give the reset a try. If I don’t get to it tonight, I should be able to mess with it on Friday.

Thanks again for the help everyone!

I don’t know if it is a direct result of my tinkering with the device but it hasn’t bugged us about updating it at all this week. We have been doing a lot more traveling this week too.

I am still trying to figure things out but I am getting there. I think I am going to get my wife a newer model and that way I get this one to tinker with new maps on without the worry of breaking it or restoring it when she needs to go on a trip.

Thanks for the help everyone!