Can GO 930 Get Confused?

[donganas]

Hi folks,

Had a little problem with my 930 and would appreciate some opinions.

The event:
Enroute from Valdosta, GA to Atlanta, GA on I-75. About half way, just south of Macon, the 930 suddenly began showing my location (Blue Arrowhead) about 500 yards to the east of my route. I make this trip regularly so I was never lost. Was just confusing in that it lost the ability to give time / distance info. due to it being in a loop, where it recomputed the route over and over. I powered on / off a couple of times with no change. After about 20 minutes I shut it off. I tried it once again about 20 miles outside of Atlanta with the same result.

Once in Atlanta, I did a "reset" using the button on the bottom. Apparently, this did the trick. The 930 performed without fail during the rest of my stay in Atalnta as well as the entire trip back to Valdosta.

I've had the unit since August 2008. Never had a problem before. In thinking back the only thing different on this trip was:

) Home 2 update to v 2.7.1.1812
) Purchased new US / Canada maps in August 2009
) Failed to use "Quick Fix" since updating maps (about 6 weeks)

My Question:

) Could any of the actions above, individually or in combination, have caused my problem?
) Is this one of those things that happens from time to time and I should forget about it an move on.
) Was this some sort of harbinger of things to come.


Thanks,

Don

 

[dhn]

Strange.......

Did you somehow lose the satellite fix at that point?

It may also be some glitch in the mapping at that point that caused the weird activity. Perhaps try a demo route that includes that point and see what happens.

 

[mvl]

An expired quickgpsfix can throw off the GPS.

Since it didn't think you were on a road, the Tomtom will automatically recalculate your route every time you move. Since you were always moving, the Tomtom ended up in a continuous recalc loop.

This appears to be a (useful) feature that assigns you to the nearest road in a parking lot, but it makes things worse with a mislocated quickgpsfix.

 

[Arno]

... the 930 suddenly began showing my location (Blue Arrowhead) about 500 yards to the east of my route.

Yes, and a dashed horizontal line from the tip of the arrow head over to the road where one should be (similar to the attachment).
I had that in Ireland a few times (only on one day) last year after driving about 2000 miles and no QuickGPSfix for about 2 weeks.
Also this year, going through the mountains from Silverton, CO to Durango after 12 days and 4000 miles without the QuickGPSfix.

After about 20 minutes I shut it off. I tried it once again about 20 miles outside of Atlanta with the same result.

I cannot say that the instances I experienced lasted for an extended period of time.
The attachment sample actually shows being in a parking lot, as mentioned by mvl.

Failed to use "Quick Fix" since updating maps (about 6 weeks)

I am reasonably certain that this is what caused it.

Is this one of those things that happens from time to time and I should forget about it an move on.

Yes, even though I am surprised that it lingered on in the wide open area around Atlanta.

 

[GarCor]

One of the things that cause this is when there has been a new or section of Hwy built after that area was last mapped with Telaatlas

I have found this to be the case especially in New Brunswick on the Trans Canada.
They have been twining the TC for several years now and it is finally completed but over the years as the different sections were completed I would get a dotted line from where I was driving to the old highway and then once we merged back on the old Hwy it would show me correctly.

 

[Arno]

That doesn't hold water for my sojourn to Ireland where TT put me in a stream !

 

[GarCor]

I hear you but as I said that is just one of the causes of showing you with a dotted line.

 

[Arno]

I guess I should have added some smilies.
Arno

 

[mvl]

Also this year, going through the mountains from Silverton, CO to Durango after 12 days and 4000 miles without the QuickGPSfix.

See if you can pair the Tomtom to your phone for bluetooth data (if you have a cell data plan). The Tomtom will pull quickgpsfix via bluetooth automatically, and you'll never need to worry about plugging it in except for map/app updates.

 

[GarCor]

I could be wrong but I thought that quick GPS fix was mainly designed to help your unit nind the sats quicker after you haven't had your unit turned on for awhile.. If Aarno was usung his unit every day I wouldn't think he would need a quick GPS fix as his unit would pick up the next day from his last location .

 

[GarCor]

I guess I should have added some smilies.
Arno

No you didn't have to add any smiles,
All I was trying to say is that whwn you state that it doesn't hold water you arn't totaly correct .
I have exeperanced the dotted line leading to an older section of Hwy or to the lastest data that Telaatles had for that area on more times than I care to mention.
I am not stating that this is the only reason but it is one of the reasons.

 

[Arno]

See if you can pair the Tomtom to your phone for bluetooth data (if you have a cell data plan). The Tomtom will pull quickgpsfix via bluetooth automatically, and you'll never need to worry about plugging it in except for map/app updates.

Although I have Data disabled on my bluetooth cell, this is excellent general advise.

 

[Arno]

I could be wrong but I thought that quick GPS fix was mainly designed to help your unit nind the sats quicker after you haven't had your unit turned on for awhile.. If Aarno was usung his unit every day I wouldn't think he would need a quick GPS fix as his unit would pick up the next day from his last location .

Yes, I had been using it all along and I think it was an intermittent triangulation satellite problem in the mountains. I don't pay it much heed as it goes away after a short time, not like Don's problem that started this thread.

 

[gatorguy]

Arno/Garcor, both of you are right in your understanding. Garcor's point that if a road's geometry has changed but the underlying TA map hasn't, you will get the off-road "dotted line". I've seen it a few times in Florida. IMHO, Garcor's also correct that, with daily use, a Quickfix download won't be much, if any, added benefit. Arno, you're also right that if for some reason you're not getting a solid lock on enough sats your TT may be mis-placing your position and determining that you're off the beaten path. A quickfix download could possibly assist with that. I'll add that on my last visit to Atlanta with a TomTom 930, I did have my location jump around a little in the downtown area. The buildings are pretty tall and thick there, so an occasional multipath error (gps signals bouncing off buildings rather than being received directly by the pnd) could be expected. A Quickfix update wouldn't avoid that.