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Nav system not accurate

Discussion in 'Gen 3 Prius Audio and Electronics' started by Gordon Stach, Jan 2, 2010.

  1. Gordon Stach

    Gordon Stach New Member

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    Has anyone experienced problems with the accuracy of their pkg 4 Prius navigation system? The cursor in my 2010 is always behind where the vehicle actually is and can't be calibrated to correct. The dealer's service mgr attempted to correct this, but the cursor immediately reverts to the old (behind) position. When programming a destination it gives directions that are not correct. The service mgr took me on a trial run with a new Prius in their inventory and it did identically the same thing. I reported this to the Toyota Customer Service Hqs in Torrence and they said, after investigating my complaints, the sytem was "functioning as designed". I have now purchased a Magellan mobile unit because of the unreliability of the on-board system that cost a fortune. I've read other chat sites that had the same complaints. My 2005 Prius Nav was great!
     
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  2. Bobsprius

    Bobsprius BobPrius

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    Sorry ot hear your having these issues. I have a V and have no problems, I think I understand your comment about the cursor, but mine is right on target.

    It has found ALL locations I have put in, and I have used it frequently to check it's accuracy based upon some comments from this forum.

    It has to date found all locations and the instructions were almost on target within feet....

    So hopefully you will like your Magellan unit better. Maybe Toyota will have a fix if this is an issue, but until then enjoy the new Magellan Unit.....
     
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  3. Joe166

    Joe166 New Member

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    I have had three or four Garmin units in my other cars and I have found the Nav unit in the Prius to be adequate. Not great, but adequate. Makes up for having to hide the unit under the seats when I park.
     
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  4. jdcollins5

    jdcollins5 Senior Member

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    Like Bobprius, I have not had any issues with my Nav unit. My unit was off calibration slightly when I parked in my driveway for the first time. I recalibrated the unit and it has been accurate to within a few feet since. It has always taken me to the addresses that I have entered with no problem.

    Sorry to hear you are having problems with your unit. I would say that what you are experiencing is not normal.
     
  5. Bobsprius

    Bobsprius BobPrius

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    At least we find it functional and useful. I sometimes believe that those that experience issues is related the Map Accuracy or a particular region and area.

    In my region area, thus far it's been great. It has not guided me in circles, it displays the Actual address when you hit the map button to within a couple addresses of accuracy. Meaning, if I was in front of 2332 Main street it may say 2334 Main street, but that's GPS related.

    But thus far I agree it beats putting in a unit that I have to plug in and remove when I go shopping or leave the vehicle due to "sticky hands".

    It's not PERFECT, but it is useful and built in. Plus you can always look at it this way it's value add at trade or sale time. :)
     
  6. Gordon Stach

    Gordon Stach New Member

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    From the comments observed so far, it looks like the problem is just in my area. I know it is not just my Prius, as the dealer's Prius tested did the same thing. The software in my vehicle was updated this past November when the annual software discs come out. At least this is what I've been told. Will have to pursue with the dealership. Thanks for your comments.
     
  7. JimN

    JimN Let the games begin!

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    Used twice in NJ. No accuracy problems. Perhaps less densely populated areas have a larger margin for error.
     
  8. Gordon Stach

    Gordon Stach New Member

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    That's not it. Have used it in Dallas and Houston metro areas with same results.
     
  9. Dark_matter_doesn't

    Dark_matter_doesn't Prius Tinkerer

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    I looked at your location in Google Earth, and your surrounding mountains may be blocking some of the GPS satellites' signals. You need at least three for a location fix, four for location & altitude. For example, you might be getting two strong signals and one weak signal, leading to an increased location error. The signals themselves are pretty weak to begin with. See if other people with GPS receivers have problems in your area.

    I just looked at my copy of the .pdf of the Nav manual. Go look at the Appendix on p. 306 for some relevant information on GPS accuracy. They mention that window films may cause problems. Have you installed them on your Prius? Again, the GPS signals are VERY weak to begin with.

    I don't think there's a readout on the Prius Nav system for how many satellites are in view - my 2003 Town & Country nav system does provide this AND provides altitude readouts, something I really miss on the Prius nav system.
     
  10. Gordon Stach

    Gordon Stach New Member

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    I can see the logic in your explanation, however my 2005 Prius had no problems with satellite reception. Also, I've traveled Houston and Dallas experiencing the same problems. I'm still thinking it could be a software problem.
     
  11. qbee42

    qbee42 My other car is a boat

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    My first guess would be the map database. I find the accuracy and completeness of the data varies a lot from place to place. With my 2006, all of the freeway exits in Utah were mislabeled by two miles! They appeared in the proper locations, but the exit numbers were all offset. Likewise, some areas have great map detail, while other areas are missing major roads. It's a crap shoot.

    A GPS system can be accurate to six feet, but if the underlying map is off, it's not going to work.

    Tom
     
  12. Gordon Stach

    Gordon Stach New Member

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    Recalibrated the unit again and this time I set the cursor ahead the same distance it's been behind. In just a couple of blocks it reverted to the same distance it had been behind the vehicle's actual position (almost a block).
     
  13. Wielicki

    Wielicki New Member

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    We also have had accuracy problems with our 2008 nav system. It has taken us in the opposite direction on interstates twice in two different states, neither case in an area of recent construction. We have stopped relying on it and use either a Garmin or a TomTom instead.
     
  14. RodJo

    RodJo Member

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    Satellite information is available from the hidden maintenance menu.
     
  15. jdcollins5

    jdcollins5 Senior Member

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    I have to believe this would go back to what qbee42 was saying about this must be that the map is off in your area. Especially if you recalibrate and after a short drive, it moves back to its original setting. That would be telling me that the system knows where it wants to be based on GPS coordinates.

    The Vehicle Service Menu will give you the GPS coordinates. The easiest way to get to this menu is to hold the Info button and turn your headlights on and off three times. (I believe this is correct ?!)

    Hold the Display button down to exit the menu.
     
  16. Econ

    Econ Member

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    WHat version is your software?
     
  17. Dark_matter_doesn't

    Dark_matter_doesn't Prius Tinkerer

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    Yes, and there's lots of satellite info BUT still no altitude data even though the display says it's in 3D mode.