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2014 Prius III. Loss of power and lower mileage

Discussion in 'Gen 3 Prius Technical Discussion' started by DaneH5, Aug 27, 2019.

  1. DaneH5

    DaneH5 Member

    Joined:
    Aug 12, 2014
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    Location:
    Pinellas, Florida
    Vehicle:
    2014 Prius
    Model:
    Three
    So for 6 months or more I have experienced drop in power and lower mpg. I have to run in power mostly to get performance close to where it was before. MPGs have dropped an average of 10 mpg or more in normal mode and can get higher when in power mode. Car was still in 5 year warranty when I took it to the dealer to be checked. Because no codes were thrown the dealer ‘expert’ was of no use and said no problem found.
    What info does tech stream return on the high voltage battery side? Does it show current consumption out of the pack ? And other important troubleshooting data?
     
    #1 DaneH5, Aug 27, 2019
  2. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
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    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Dr Prius (phone app) plus a OBD bluetooth adapter can show battery info. I've so far just done a static test, looks like this:

    IMG_0874.PNG

    There are more in-depth tests you can do, accel/decel while driving, and one where you just have it idling, under certain load parameters. Gives more of a health assessment.

    I've not done those as yet.

    How many miles btw?
     
    #2 Mendel Leisk, Aug 27, 2019
  3. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
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    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    how many miles on her? you are aware that power/normal/eco modes are just throttle position mapping?
     
    #3 bisco, Aug 27, 2019
  4. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
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    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Check your 12v bat health. When it’s not able to retain adequate charge anymore, hv bat will continue to send power to the 12v bat until it tops off. If 12v bat can’t top off anymore, well then hv bat will just keep sending power to the 12v bat resulting lower mpgs.
     
    #4 Grit, Aug 31, 2019
  5. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
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    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Those are great numbers (y)

    This morning I drove back from the dam, SOC was at 80% :cool:
     
    #5 Grit, Aug 31, 2019
    Mendel Leisk likes this.
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