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Navigation lost location for 10 minutes today

Discussion in 'Gen 3 Prius Audio and Electronics' started by Jared, May 30, 2013.

  1. Jared

    Jared Member

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    I have a 2010 Prius with 76k miles. Today I looked down at the nav screen and noticed the location was off by a few miles. This has never happened before. I stopped and turned the car off and on and it was still wrong. Even the direction North was wrong. Luckily, it went back to normal after about 10 minutes. Do you think this is an issue with the car's electronics or with a GPS satellite?

    I just read a report from Japan saying that solar flares could be bad this week and they can affect GPS accuracy. Anyone else have a navigation problem?

    Solar Flares May Affect GPS Systems This Week, Researcher Says - UT Dallas News
     
  2. jdcollins5

    jdcollins5 Senior Member

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    I did not have any issues with mine driving to work this morning between 7:00 to 7:30.
     
  3. xs650

    xs650 Senior Member

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    It's highly unlikely that a solar flare could make your GPS lie to you. The typical result would be that it would degrade the signal to the point where it just wouldn't work.

    I don't have the factory GPS in my 2010, but some built in GPS systems use the cars odometer, accelerometers and sometimes compass to continue navigation when satellite signal is lost. I have seen that cause errors of a couple hundred yards after several minutes in other cars, but nothing close to a few miles.
     
  4. macman408

    macman408 Electron Guidance Counselor

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    Another possible cause is just the way GPS works. GPS sends some data regarding the locations of satellites, atmospheric conditions that affect GPS accuracy, and a variety of other things. This data takes a long time to transmit - on the order of 12 minutes or so. Most of the time, a GPS device doesn't need to wait this long - it might have the information (or at least, enough information) from last time it was used; or (like for cell phones with GPS) it can also pick up this information from another source that is faster. So it's possible that the car was just taking a best guess at where you were located, and once it had received all the data needed, it was able to determine your location much more accurately.

    Not a problem with either your car or the GPS system - just the way it works.

    There are, of course, many other possibilities. Solar flares as you mentioned, or if you're near tall buildings or mountains (I've often had my location drift when I drive on curvy mountain roads where it can't see as many satellites as it needs to), etc.
     
  5. Jared

    Jared Member

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    Thanks for this.

    I read the Navigation booklet that came with the car and it lists many reasons that the nav system may be inaccurate. I noticed today that it was ok most of the time on the highway but at one point it thought I was on a parallel service road. And there were a few times that the GPS Light was not lit for several minutes. I think solar activity may be a factor in this since I have not noticed inaccuracy in the past and the news reports do say there is a lot of solar activity now. At worst, my GPS loses track of direction and does not know where North is. I don't mind as long as it recovers within five minutes.
     
  6. Jared

    Jared Member

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    I lost location again today for about 30 minutes on the highway. If no one else is having problems it must be my car GPS receiver. I don't think it would be under warranty. I had the 75K warranty and am now past that mileage.