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ScanGauge erroneous MPG readings

Discussion in 'Gen 2 Prius Technical Discussion' started by Doc Willie, Aug 3, 2007.

  1. Doc Willie

    Doc Willie Shuttlecraft Commander

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    I reset the Tank readings on the ScanGauge according to the instructions to do an initial calibration. Since then, I am getting ridiculous readings, e.g., 13 MPG on the ScanGauge. My MFD readings are unchanged, and my actual usage appears unchanged, estimating from how long it took to use up the first bar on the gas gauge.

    I checked the Settings and they seem to be OK.

    Is this normal during calibration? Will it correct when I adjust it after the next tank? Should I just go back to the Defaults, and try a calibration later?

    None of this, of course, is life threatening. Only my sanity and my OCD diagnosis are at risk.

    <div class='quotetop'>QUOTE(Doc Willie @ Aug 3 2007, 06:45 AM) [snapback]489862[/snapback]</div>
    . . .

    I just re-Read The Friendly Manual, and it says an error was most likely made aftewr the fillup adjustment (which i didn't do, I just reset the Tank to full). Or maybe I did and don't remember. I don't know.

    Whatever.
     
  2. David Beale

    David Beale Senior Member

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    Mine read exactly the same as the MFD as soon as I plugged it in. And it had been running in the anti-Prius (2001 Pathfinder) for almost a year before. Did it read the same as the MFD before you messed with it? If so, reset and leave it alone. ;)

    The settings I use are:
    Fuel type - hybrid
    engine size - 1.5 L
    tank size - 45 L

    You can set these in metric mode and then switch the unit to US mode and the fuel tank size should auto convert. Makes it easier to get the exact tank size set.
     
  3. Doc Willie

    Doc Willie Shuttlecraft Commander

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    <div class='quotetop'>QUOTE(David Beale @ Aug 3 2007, 12:55 PM) [snapback]489994[/snapback]</div>
    Yeah, it was accurate before I did the tank fillup and reset.

    I think it is reading exactly half the MPG. Also, it reads that I have only 2.2 gals left, although that is about how much I have used. I will wait to the next tank fill and finish the calibration procedure and see what happens.
     
  4. tekn0wledg

    tekn0wledg New Member

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    If you adjust the gallons filled when you get gas, if the gallons used versus filled are significantly different, it can cause this behavior to occur.

    This happened to me during my first fillup with the SGII. I adjusted the gallons filled to the appropriate level, and then it was reporting my MPG at like 17mpg.

    To fix it I went into the fuel screen and adjusted down the figures back to zero, which took a while, and then everything was back to within 3% accuracy of the MFD.

    Also, you need to make sure you have updated your engine type to Hybrid and the 1.5 liter. Make sure you adjust your fuel capacity as well.

    Typically I see an SGII difference of about 3% from the MFD.