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Gen 1 Prius' sudden MPG drop

Discussion in 'Newbie Forum' started by Jacob Harris, Feb 14, 2013.

  1. Jacob Harris

    Jacob Harris New Member

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    Hey folks,
    My fiancée and I bought a 2002 Prius w/ 100k miles on it about a year and a half ago.
    Since then we've put about 30k on it, and starting last April or so, the MPG has been gradually dropping.

    At first it wasn't so obvious, but now we're averaging around 21/35 -- which is paltry to say the least.
    We've replaced the voltage inverter and both the electric-motor battery and the starter battery - plus maintaing air in tires.


    Our mechanic here in SF also had the car at their shop, and after weeks of testing and driving it, they couldn't figure it out either. No computer codes, no nothing.
    Obviously this is turning into a bit of a money-pit. I have wondered if maybe the ECU needs to be replaced?

    Has anyone had any experience with this issue? I saw on the forum that their were similar issues with a GII Prius.

    Any thoughts would be appreciated. Thanks.
     
    #1 Jacob Harris, Feb 14, 2013
  2. Jacob Harris

    Jacob Harris New Member

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    Nudging.
    Even a link to a previous thread I have overlooked would be appreciated.
     
    #2 Jacob Harris, Feb 17, 2013
  3. ny_rob

    ny_rob Senior Member

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    11 year old hybrid battery at end of life?
     
    #3 ny_rob, Feb 17, 2013
  4. Jacob Harris

    Jacob Harris New Member

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    It's not that, we just got the battery replaced about 6 months ago.
    Could the ECU be involved in any way?
     
    #4 Jacob Harris, Feb 18, 2013
  5. ny_rob

    ny_rob Senior Member

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    Ok- I reread you post- you called it "the electric motor battery".
    You replaced it with a new hybrid battery or one from a used vehicle?
    Have you brought it to a hybrid specialist like a Toyota dealership?
     
    #5 ny_rob, Feb 18, 2013
  6. Jacob Harris

    Jacob Harris New Member

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    Yes, the hybrid battery I meant to say.
    We have taken it in. Luscious Garage here in SF, who specialize in hybrids (they service all the taxi fleets' hybrids and are very reputable).
    They had the car for almost two months and couldn't find anything. No computer codes, nothing on our dashboard; no indication whatsoever.
     
    #6 Jacob Harris, Feb 18, 2013
  7. cycledrum

    cycledrum PSOCSOASP

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    Is it an option to take it to Toyota? No disrespect of Luscious, but Toyota is the mother ship.

    Not an exact comparison, but in about '94, my Jetta had crazy problems - it might run fine, or fail. I took it to VW / german car specialist in Santa Clara who had it for days and had no idea what was wrong....

    Finally I took the Jetta to the VW dealer who correctly diagnosed a bad ECU. Replaced it and it was fine thereafter.

    I would take the car to Toyota and their Prius specialists should look at it.
     
    #7 cycledrum, Feb 18, 2013
  8. Jacob Harris

    Jacob Harris New Member

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    You may be right about that. I guess I only expect the dealer to gouge, but at this point I'm happy to try anything.
     
    #8 Jacob Harris, Feb 19, 2013
  9. ny_rob

    ny_rob Senior Member

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    You never answered Jacob- did you replace the hybrid battery with a new one from Toyota or a used one (from salvage,etc) ?
     
    #9 ny_rob, Feb 19, 2013
  10. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    I would check the wheel bearings and brakes. Look for something that is causing drag. Bad wheel bearings cause excessive drag as do warped rotors.
     
    #10 usnavystgc, Feb 19, 2013
  11. detroit11

    detroit11 Junior Member

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    how much did you pay for the battery ?
     
    #11 detroit11, Feb 21, 2013
  12. scotman27

    scotman27 Active Member

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    mine did the same thing right before winter. here my front right caliper was stuck , the car would not pull to the right when braking or shake or anything. but my milage dropped to about 37 because of it. so i jacked up the car and checked all brakes, once i got to the front right tire it was hard to turn, i pryed back on the caliper, and spun the wheel, all good, reapplied and tried to spin it, it was tight again. bought a new caliper and installed it, my mileage went right back up to 46+. try that
     
    #12 scotman27, Feb 22, 2013
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