Gen 3 - J0V Recall - Bad MPG - ECU Swap

Discussion in 'Gen 3 Prius Main Forum' started by JonathanCWard, Sep 12, 2020.

  1. Elektroingenieur

    Elektroingenieur Senior Member

    Joined:
    Jan 8, 2017
    2,223
    2,978
    9
    Location:
    California
    Vehicle:
    2016 Prius
    Model:
    Three Touring
    Toyota’s engineers have determined that software changes are necessary to prevent damage to the transistors in the inverter with converter assembly, and to prevent sudden and unexpected loss of motive power in certain non-normal scenarios. Their company believes so firmly in the need to apply these countermeasures that it has accepted the public embarrassment and adverse publicity of a series of safety recalls. (See Toyota’s defect information reports to NHTSA of February 12, 2014, October 4, 2018, and June 24, 2020.)

    In this situation, I could only advise you to use the latest software from Toyota. Assuming, just for the sake of argument, that there has been a loss of fuel economy, and that there is no other cause, consider this the price of operating the hybrid system within the limits that are needed to ensure its durability and safety.
     
  2. Johnny Cakes

    Johnny Cakes Senior Member

    Joined:
    Dec 30, 2016
    807
    618
    2
    Location:
    Virginia, USA
    Vehicle:
    2015 Prius
    Model:
    Five
    The beauty of the USA is that everyone gets to make their own decisions. From his posts in this thread, the OP clearly understands the situation the software upgrade is designed to address. He made a big boy decision that that situation is so unlikely that a 33% increase in day-to-day MPG was worth it. You don't have to make the same decision, but it is a reasoned decision.

    Mostly, I just hope the OP circles back and reports what he finds out. And with his Toyota insider background, a few more posts in various threads wouldn't be bad either! :)
     
    tvpierce, JonathanCWard and royrose like this.
  3. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    15,231
    10,600
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    ... disregarding the likely misattribution of the MPG change.
     
  4. JonathanCWard

    JonathanCWard New Member

    Joined:
    Sep 8, 2020
    20
    9
    0
    Location:
    Los Angeles
    Vehicle:
    2013 Prius
    Model:
    Persona
    Hey Johnny, rest assured, I’m not going anywhere. I have been using this (as a reader) for years. Of which times it has been helpful for my own maintenance. I found that most of those threads were old by the time I was reading them and could not contribute from my experience anything that would help or may had not been said yet. I have helped out in the Toyota Prius owners Facebook page for years but not here, and plan to now that I finally created an account.
    Thanks for chiming In on my issue as it’s a strange and unfortunate one. Again, I’m nowhere near new to these cars and for the most part understand them. None of my previous cars (nor did this one) ever get such bad mileage prior to this recall. Many may think it has nothing to do with recall, but based on my research and maintenance performed, I can not help but think it continually leads back to the recall. Soon, hopefully if I am fortunate, I will know.
    That said, not sure the ecu swap will correct it as it has been stated the programming is updated in the MG ECU and Power Module ECU. Located inside the inverter and behind the glove box.
     
    Lucas Fox, framistat and GG707 like this.
  5. Michael Wood

    Michael Wood Member

    Joined:
    Jun 19, 2016
    103
    83
    3
    Location:
    Boston, MA
    Vehicle:
    2020 Prius Prime
    Model:
    LE
    This is great original post and something I've been thinking a lot about. I see very little upside to taking my Gen 3 Prius to a Toyota Dealer to have them tinker with a car that runs perfectly and is "out of warranty". It seems that Toyota was forced to develop a software patch to remedy a potential safety issue. The testing and engineering that went into this "fix" leans heavily toward reducing Toyota's liability, and not into my well-being or the longevity of my vehicle.

    The probability of my having an inverter problem doesn't appear to be high enough to justify exposing myself to a stealership and all of the revenue generating opportunities that this "fix" may create.
     
  6. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    15,231
    10,600
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    So far, my experience with my local dealership is whenever I go in for a firmware update of any ECU, whether under a recall or a TSB, I stand at the counter and tell them that's what I'd like them to do, they do that, and I drive the car away.

    If you feel like being even more explicit and saying "by the way, I'm not interested in anything else", that probably works too.
     
  7. Michael Wood

    Michael Wood Member

    Joined:
    Jun 19, 2016
    103
    83
    3
    Location:
    Boston, MA
    Vehicle:
    2020 Prius Prime
    Model:
    LE
    I'm more concerned about the update itself. In my documentation from Toyota they say, "Toyota has received some reports where the (IPM) Intelligent Power Module may fail". While serious for Toyota from a liability standpoint, it doesn't feel like it carries much owner risk for me.

    Anytime a manufacturer needs to update my firmware to address a liability issue, I end up running slower and less efficiently. I haven't done a single update on my 2015 since I bought it.
     
  8. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    5,302
    3,740
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    o_O
     
    Majafamily likes this.
  9. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    15,231
    10,600
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The J0V firmware fix is to change the reaction of the power management control ECU in a particular case where an IPM fails while driving. The reaction you would like is a reduced-power limp mode to get you safely out of traffic. The reaction without the J0V patch is an instant power-off.

    This is not the kind of change that does much to your everyday driving experience, unless you're in the habit of frying IPMs right and left.
     
    Michael Wood likes this.
  10. Grit

    Grit Senior Member

    Joined:
    Aug 22, 2017
    5,302
    3,740
    1
    Location:
    Wilkes Land
    Vehicle:
    2012 Prius
    Model:
    Four
    Then what happens when you get in a accumulative update situation and every update is uploaded to the car including the one that lowers your mpgs?
     
  11. Fitcious

    Fitcious Member

    Joined:
    Feb 12, 2020
    183
    75
    0
    Location:
    Los Angeles
    Vehicle:
    2013 Prius
    Model:
    Four
    Which dealership were you working for? Just curious. I was a trainer with Toyota corporate for 7 years and joined a dealership group a few years ago.


    iPhone ?
     
  12. Lucas Fox

    Lucas Fox New Member

    Joined:
    Dec 16, 2021
    2
    0
    0
    Location:
    Central , Illinois
    Vehicle:
    2012 Prius
    Model:
    Four
    What was the outcome of the ECU swap?
    I am having the same issue with my 2012 Prius. Though I was having MPG issues before the software update.

    Thanks,
     
Loading...