Speedometer Wildly Exaggerating Speed.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by bellverde, Jun 20, 2010.

  1. bellverde

    bellverde New Member

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    I began a 1200 mile road trip today from Northwest Indiana to Central Texas. About 6 hours into todays 12 hour stretch, I stopped for lunch and filled up at a BP (because it was the simplest station to access--I did think twice about it). Upon getting back on the highway, I looked down to check my speed and about had a heart attack. My car said I was going 120 mph. So, I took my foot off the brake, chastised myself for myself for the newly developed lead foot, and then looked up to my Garmin where it said I was now going 53 mph. Deeply confused, I looked back and forth, experimenting with my speed and discovered that my speedometer had somehow busted. My average speed of 70 mph reads about 42 mph higher and at 60, only about 28 mph higher. There seems to be some multiplier and not a straight discrepancy.

    I have another day of driving ahead of me tomorrow, and I'd sure like to know if this is my car rejecting BP's mojo, something I can fix, or if it's more dire. I plan to seek out a dealer tomorrow, but would appreciate feedback asap.
     
    #1 bellverde, Jun 20, 2010
  2. eestlane

    eestlane Member

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    Is it possible you accidentally switched the speedo to KPH?
     
    #2 eestlane, Jun 20, 2010
  3. fuzzy1

    fuzzy1 Senior Member

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    Did you accidentally hit the button that converts the display to kilometers per hour? (Does the 2008 even have this? My 2010 does.)
     
    #3 fuzzy1, Jun 20, 2010
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  4. Ophbalance

    Ophbalance Member

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    Try a search on "combination meter". If memory serves, if this piece of hardware starts to glitch, that would be one of the results. I could, however, be mistaken in my recollection.
     
    #4 Ophbalance, Jun 20, 2010
  5. BAllanJ

    BAllanJ Active Member

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    Are you sure you didn't hit the little button near the odo button and switch the speedo to km/hr instead of mph? 120 km/hr is a little over 70 mph.
     
    #5 BAllanJ, Jun 20, 2010
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  6. 2009Prius

    2009Prius A Wimpy DIYer

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    70+42 km = 69.6 mile
    60+28 km = 54.7 mile

    The second data point is a bit off but the first one seems right on as others suggested the speed unit was changed to km/hr.
     
    #6 2009Prius, Jun 20, 2010
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  7. derkraut

    derkraut Member

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    You undoubtedly inadvertently switched your speedo to KPH from MPH. The owners manual tells you how to switch it back.

    PS: enjoy the rest of your trip!
     
    #7 derkraut, Jun 20, 2010
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  8. BAllanJ

    BAllanJ Active Member

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    Or you could join the rest of the world and leave it in km.:D
     
    #8 BAllanJ, Jun 21, 2010
  9. autoxic

    autoxic Commuter

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    LOL. This is so funny! Most of us here on PriusChat have guessed that you hit the MPH/KPH button on the dashboard (maybe above the touch screen). Thanks for making me laugh (at your expense). Sorry, must... stop... giggling.

    Anyway, there should be a really small LCD indicator near the speed display letting you know if the speed is in KPH or MPH. My 2004 has this, if I remember right.
     
    #9 autoxic, Jun 21, 2010
  10. kenoarto

    kenoarto Senior Member

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    Hey, we actually had a chance to use the button, (on purpose LOL) crossing into Canada.
     
    #10 kenoarto, Jun 21, 2010
  11. Rae Vynn

    Rae Vynn Artist In Residence

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    The button is below the MFD, and next to the ODO button. Push it.


    There ya go.
     
    #11 Rae Vynn, Jun 21, 2010
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  12. JimN

    JimN Let the games begin!

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    "My car said I was going 120 mph. So, I took my foot off the brake..."

    So that's the secret to high speed driving...

    Congratulations!! You have mastered the Sikes Maneuver. (Setting the brakes on fire is optional--but a show stopper.)

    I'm not going to bust on you for pressing a button but remember this for when you want to freak out a passenger.
     
    #12 JimN, Jun 21, 2010
  13. bellverde

    bellverde New Member

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    As almost all of you have suggested, the only thing wrong with my speedometer was that it was reading kilometers instead of miles. Somehow, the dog or I hit the button under the touch screen and switched the setting. And, the day was bright enough that I couldn't actually read the units of measure. The nice service department at the dealership didn't laugh at me or anything and even donated a couple biscuits to the dog before sending us on our way with a lesson learned. Thanks for all the helpful comments.
     
    #13 bellverde, Jun 28, 2010
  14. bellverde

    bellverde New Member

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    Oops, 12 hours of driving scrambled my brain a little. Good thing I was off the road....
     
    #14 bellverde, Jun 28, 2010
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