Thread: About 37xx converted to 34xx satellites reception accuracy

Yes, that's what i meant. WU/GE/MD would just dl the 37xx fw and files.

A bit more info: ASR doesn't work with either ASR 1 or ASR 2 files. I'll play a bit more with that.

Sat accuracy seems the same as my other convert, varied 4 to 10 metres today in mostly overcast suburban running (no tall buildings) in half-hr test. This unit and my other 2 showed rock solid 3 m before as 3790s which i find to be unrealistic in any case [just artificially enhanced with hotfix?]. From full off, about 4 mins until 'ready to navigate'. From standby 60-70 m quickly backing off to 8/9 m between 30 sec to a minute. I'd suspect hotfix is not working on these converts because while navigating there seems to be no problem, at least with both my 37>34. No car navigator needs 3 m accuracy anyway, imo up to 15m is fine, and i doubt any 'non-pro' receivers truly achieve 3 m constantly in reality without sw and/or SBAS enhancement.

I'll try a 34x0 logo flash if you want me to, but the logo's really not a problem.

Ok, so it totally looks like bootloader has nothing to do with GPS accuracy.
I've spent only about 1.5 day writing gfwpack.exe and I've got an interesting (and probably useful after some modification) piece of software, so I'm not disappointed.

If we manage to somehow extract from 37xx GPS Fw and add it in 34xx Fw then maybe it will all work OK.

@lolypop000
As you proposed back in Post #15 and it's timely for it to be raised again after some other seemingly plausible hypotheses have been debunked in practice. Can you help with such a mod?

Kunix's total rebuilding [it would be trite to call that a 'mod'] of the fw which i tested yesterday is mind-blowing to me. Sure it has a few rough edges which i'm sure he could smooth off quicker than i could make a coffee but it worked overall and seemingly achieved the objective, i.e. to establish if the 37 bootloader would improve accuracy as proposed by Angelozip. I couldn't see that it does during my brief test but have left the unit converted and will do a triple side-by-side with it, a virgin 3790 and another 3790>3490 conventionally converted. Maybe throw in my 3590 as 4th which is as close as i've got to an original 3490. I'll post the results of that soon.

Kunix, are you prepared to invest a little more time to extract the 37x0 GPS fw and mod it into either the original 34x0 or your creation [or both]? I'm happy to test further, no doubt others will also volunteer.

No, I'm not at all sure by my own enquiries. I'm only going by what lolypop000 has said.

Maybe GPS FW is in some NVM region and it's only writen in FW, becouse when you convert from 37xx to 34xx GPS FW don't change.
Already google all for GPS FW, read all post on Noeman but can't find answer where is GPS FW.
Someone here on Noeman write about region 91 but don't know what is inside this region.

Do we have UAT FW of nuvi 37xx or 34xx?
Maybe there we can find answer.

GPS Firmware could also be inside GPS Chip.

Maybe upgradable by Nuvi