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Need help with changing my ECU

Discussion in 'Gen 2 Prius Technical Discussion' started by Rica8158, Sep 14, 2018.

  1. Rica8158

    Rica8158 New Member

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    So I have a 2005 and my battery went bad. I bought a new battery from toyota and went to install the battery but realized that the new battery does not have the ecu on it. I tried searching but couldn't find any info online on how to do this and I am just trying to be careful as I know the battery is packing like 200 volts. Can anybody here lead me to some info on swapping a new toyota battery from the dealer.
    Edit: forgot to mention that the dealership told me not to open the battery pack or else I lose my 1350 core deposit. Am hoping this is not required.
     
  2. davecook89t

    davecook89t Senior Member

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    The guy in this video does not say a word (perhaps he doesn't speak English), but the video does show a replacement of the HV battery ECU. You would need to remove the cover over the electronics, but not the cover over the battery pack itself. The video also does not show him removing the orange safety plug and testing for residual voltage across the orange cable connectors while wearing safety gloves, but that is definitely the necessary first step. I hope this helps.
     
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  3. Rica8158

    Rica8158 New Member

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    dang I thought the ecu was all that extra electrical stuff too. My new battery literally doesn't have any of that. Will upload pic of my battery to show.
     

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  4. Dxta

    Dxta Senior Member

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    To be on the safer side, you got to remove the service plug. You could mistakenly get yourself killed, when attempting to remove the battery ECU.
     
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  5. Rica8158

    Rica8158 New Member

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    This is the whole battery
     

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  6. Rica8158

    Rica8158 New Member

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    yes I have it removed. The orange one correct? I am still not sure what parts are carrying voltage though so better safe than sorry.
     
  7. Skibob

    Skibob Senior Member

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    Just curious how much was the new battery?
     
  8. Rica8158

    Rica8158 New Member

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    paid 3924.81 but will be getting 1350 back as a core charge hopefully.
     
  9. davecook89t

    davecook89t Senior Member

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    You will need to reattach all of the things that were hooked up to your original battery. Hopefully they are still in the car. I don't think anyone who sells you a battery is going to attach any other electronics unless you make arrangements to buy them as well. You got everything that you would normally get.
     
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  10. Rica8158

    Rica8158 New Member

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    Yeah I am looking for info on how to attach my old stuff from the old battery. I don't want to get electrocuted as I am unsure what is still energized after removing the orange safety plug.
     
  11. davecook89t

    davecook89t Senior Member

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    Everything I've read indicates that if you measure 0 Volts (or close to 0 Volts) across the 2 connectors shown in the attached picture, and do not open the case of the HV battery, you will not get electrocuted. I believe you should keep your safety gloves on until after you've measured 0 Volts across those 2 connectors.

    High Voltage Connectors.JPG
     
  12. ericbecky

    ericbecky Hybrid Battery Hero

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    You will need to open up bother batteries.
    Transfer quite a few parts from old pack to the new pack. Hoses, black separator, computer, contactor, white plastic rectangle, metal end plate, etc.

    Then must properly package old pack. Place 2 rubber mats over modules, remove possible and negative cables, orange plug. Bag up orange connections. Label with VIN, miles, etc
     
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  13. Texas Hybrid Batteries

    Texas Hybrid Batteries Senior Member

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    This is wrong. You must take the cover off of the old battery in order to transfer the necessary parts over to the new unit.

    This is the control assembly off of the battery. To get this off of your old pack you need to remove the cover. Remove both of the main cables. Remove the service plug housing and associated cables and finally the ECU. Once you get all of that off there are 3 10mm nuts that hold the control assembly on. Everything goes on the new battery in reverse order.
    upload_2018-9-16_14-52-37.png

    Hope that helps,
    Matt
     
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  14. Rica8158

    Rica8158 New Member

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    Thanks Matt. I called the dealership again to let then know I have to open the case to switch some parts and even asked them to talk with their technicians and see. According to them I do not need to open the case and doing so will result in loss of my core charge. So it looks like I'm going to just send it over to them because they are only charging me 800 and that is less than losing the core charge 1350. Personally think they're still wrong but would rather not do it myself and lose the core charge and be stuck with my old battery. Thanks again.
     
  15. Rica8158

    Rica8158 New Member

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    Thanks for your help. I called them again and they warned me not to open it still because I would lose my 1350 core deposit. I honestly believe you are right but I don't want to lose my core as that is less than what they are charging for labor to switch (800).
     
  16. Prodigyplace

    Prodigyplace Senior Member

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    If the dealer installs you should get a 3 year warranty instead of the 1 year warranty if you installed it yourself.
     
  17. audiodave

    audiodave Active Member

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    My dealer has that install down to 35-40 minutes. 800 is a good money maker with the core charge scare. Love the dealers.

    Posted via the PriusChat mobile app.
     
  18. ericbecky

    ericbecky Hybrid Battery Hero

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    If they are selling you an unassembled Toyota pack that has new cells I would challenge your dealer.

    It is impossible to do the job without opening it.
    I will gladly put down an $800 bet on that.

    I would be willing to call the dealer to advocate on your behalf as well. Contact me at 608-729-4082.

    I am also willing to walk you through things as well.

    Your profile says Bay Area, is that the San Francisco Bay area?
     
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  19. Rica8158

    Rica8158 New Member

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    yeah but I can't argue with them as they are holding money. Very fishy.
     
  20. ericbecky

    ericbecky Hybrid Battery Hero

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    You can return the part and ask for your money back and use a different dealer or possibly from an independent shop.

    Especially if you are in the San Francisco Bay area.
     
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