# Corrupt Sat Nav Display



## rustysheriff360 (Jan 17, 2015)

Anybody had this happen to theirs before?


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## Toshiba (Jul 8, 2004)

Primary dials are ok, so its not a system fault would be my guess.
Try resetting the MMI and give it another go. if the fails, try a reset to factory via the menu

Whats it look like on any of the other screens? i.e. car, TEL or whatever...


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## rustysheriff360 (Jan 17, 2015)

Thanks Toshiba, I will try the options you suggested.

I suppose the only thing unusual about my journey was that I started the route and then only moved about 1/4 mile in over an hour. After about an hour of actually moving at normal speeds, the problem cleared.

All the others menus were fine, purely the navigation application view. If I pressed view or zoomed in or out on the map, the problem remained.

I don't use the navigation that much but will start using it for my normal routes to see if this issue reappears.


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## Omychron (Sep 9, 2016)

Makes me think of the artifacts computer graphics cards output when overclocked and/or overheated.
Might have just been a cooling issue too?


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## Toshiba (Jul 8, 2004)

But you would then expect it to be the whole display and primary instruments were displayed fine..
its a strange one..


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## Snake TT (Jul 13, 2007)

My first thoughts were graphics chip overheating/on its way out. But I agree, surely the dials would also be affected? It could just be the map software. Are all other screens ok such as media, phone etc?


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## EvilTed (Feb 5, 2016)

Any chance you've recently done a map update? could be corrupt map data causing the problems.

I agree with everyone else - if it was GPU then all other screens / dials should be failing too, not just specific parts of it (unless they only put nav rendering through the GPU but that would be weird)


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## EvilTed (Feb 5, 2016)

The other, possibly more plausible, option is that this was a transmission error on Google Maps data. If you have Google maps as your display then perhaps a failure in the download of the satellite overlay caused this problem.
Should be resolved when the cache flushes and it gets new data.


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## ZephyR2 (Feb 20, 2013)

I reckon its a software glitch with the nav. It looks like the display is overlaying your new positions without clearing the old position leading to the same images building up in slightly different positions. 
I guess this is as a result of you only moving 1/4 mile in over an hour. You movements being so slow and small are not enough to kick in the GPS sensor that tells the nav that you have moved and the screen needs to be redrawn. But I suspect the system does a refresh periodically leading to the built up of layers. Later leading to a buffer overflow error or something which causes the large aberrations.


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## EvilTed (Feb 5, 2016)

There's a clever man, right there.
Apart from the blatant and misguided use of the term "buffer overflow" that's a great explanation and super detective work.


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## pcbbc (Sep 4, 2009)

Snake TT said:


> My first thoughts were graphics chip overheating/on its way out. But I agree, surely the dials would also be affected? It could just be the map software. Are all other screens ok such as media, phone etc?


As you can read here the Audi VC actually consists of 2 NVIDIA Tegra 3 VCMs (Visual Computing Module).


> ... There are actually two Nvidia VCMs in there. A second module drives the navigation system.


In fact I would be at all surprised if one VCM is dedicated entirely to the Nav/Infotainment, while the other is used solely for the mission critical instrument cluster work (e.g. dials and safety). Its specifically designed that way so that bugs in one system cannot impact on the other, potentially making the car undrivable (beause you do not have a speedo for example).

Regardless compositing of the various layers of the video display will all be done by dedicated hardware, so it's not at all surprising seeing rendering bugs which only effect a single layer.


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## ZephyR2 (Feb 20, 2013)

EvilTed said:


> There's a clever man, right there.
> Apart from the blatant and misguided use of the term "buffer overflow" that's a great explanation and super detective work.


LOL. Yes I'll happily accept the misuse of buffer overflow accusation although I did qualify by adding "or something".


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## J400uk (Dec 6, 2009)

That looks really odd, never seen anything like it! How old is your TT, still under warranty?


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## rustysheriff360 (Jan 17, 2015)

J400uk said:


> That looks really odd, never seen anything like it! How old is your TT, still under warranty?


March 2017. It's got warranty until March 2020.


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## pcbbc (Sep 4, 2009)

J400uk said:


> That looks really odd, never seen anything like it! How old is your TT, still under warranty?


It is odd, but I doubt very much caused by anything other than a software bug.

Rather like this one
Dealers suggestion: Turn off online traffic, it will go away...
He was correct, but hardly a great answer as that is one of the selling points of Audi Connect. :twisted: [smiley=argue.gif] 

Luckily it eventually stopped doing it, presumably after Audi's data suppliers fixed whatever crap data they were sending for a particular set of roadworks.


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## ZephyR2 (Feb 20, 2013)

pcbbc said:


> J400uk said:
> 
> 
> > That looks really odd, never seen anything like it! How old is your TT, still under warranty?
> ...


 :lol: :lol: :lol: Traffic related delays of 149,130 hours and 51 minutes. I take it you're still there then.


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## pcbbc (Sep 4, 2009)

ZephyR2 said:


> :lol: :lol: :lol: Traffic related delays of 149,130 hours and 51 minutes. I take it you're still there then.


Yes, only another 16 years to go. 

Being a computer programmer:
149,130 hours 51 minutes = 8,947,851 minutes = 536,871,060 seconds
In hex that's: 0x20000094
Close to an exact power of 2, but no cigar. I strongly suspect it has something to do with it though.
Perhaps an errant flag of 0x20000000 combined with 0x94 seconds of delay = 2 minutes 28 seconds? Seems more reasonable!

The interesting thing is the nav point blank refused to route around it. The 2 alternative routes it proposed had significantly less delays, but had to be selected manually. i.e. No "Your route has been changed due to current traffic conditions" message.


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