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Gen 4 Engine into Gen 3 Prius Partial Guide

Discussion in 'Gen 3 Prius Technical Discussion' started by Alexander D, Feb 17, 2020.

  1. Erik Kleiva

    Erik Kleiva New Member

    Joined:
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    Location:
    Hansville WA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    New member, 1st post.
    Purchased May 2020. 2012 Prius V five, 198000 miles. Removed and thoroughly cleaned the entire egr system and intake manifold, right away. It was of course completely blocked.
    Never, in my life, have I ever, run an engine out of oil, till now. It made the engine very unhappy. Started making a helluva racket from the engine while flyin down the freeway at 70mph. Pulled over and it took 4 quarts to show full on the dipstick.
    My fault. The damage could have been avoided or at least postponed for a while, had I simply checked the oil...
    Anyway, hard lesson learned!
    I am gettin ready to do a gen 4 engine swap into my gen 3 V. Cleaned the garage. Borrowed my buddies cherry picker. 2 pairs of jack stands. Plenty of tools, etc. Read all the threads. Watched all the videos. Just need to pick out an engine and get it here. There are so many to choose from!
    And commit...
    Plan is to follow the recommended steps as far as retaining all the gen 3 stuff and swap over to gen 4 engine.
    While I have it in the garage and my mind in it, I will finally install my PriusOffroad lift kit, 2 new struts, 2 new shocks, 4 new tires and a brake overhaul and move on with my life!
    The info you guys have gathered and shared here is fantastic! Grateful.
    I do have 1 question. Any engine with 5th character, A or B and 7th and 8th FU only? That seems to be 2016 - 2019? Correct?
     
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  2. Erik Kleiva

    Erik Kleiva New Member

    Joined:
    Jan 30, 2022
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    Location:
    Hansville WA
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Finished up engine swap today
    2019 gen 4 73000 miles installed inplace of 2012 Prius V gen3 198000 miles
    Retained all gen3 stuff except water pump.
    Relatively straight forward thanks to taking my time and everyone’s contributions here.
    Thank you!

    Now, here’s my dilemma…
    It won’t start. Ready light does not come on. A whole bunch of dash lights lit. If I try to move the shifter knob an indicator lights showing “push” the park button. I know I’m missing something simple.
    Brand new 12v battery and 2 bars showing for big battery.
    Any thoughts?!
     
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  3. Erik Kleiva

    Erik Kleiva New Member

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    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Thanks for your help everyone! Lol! Yes, I am being a smart nice person...
    I figured it out on my own.
    I dug up my old Windows 7 laptop collecting dust in a closet buried under 2 other old laptops, that had Techstream on it and I scrounged up my old vci cable/interface buried in a box in the garage and pulled the code that told me my hybrid battery wasn't connected!

    I was unaware of the last step of clicking the slider lever to the right to connect the little jumper plug when reinstalling the safety disconnect from the big battery.

    She fired right up, clattered for a few seconds and smoothed out and purred like a happy Prius motor should!

    I seriously would/could not have attempted this project without the contributions of so many here! Thank you, seriously!!!
     
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  4. ASRDogman

    ASRDogman Senior Member

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    Glad you got it going!
     
  5. Mendel Leisk

    Mendel Leisk Luddite

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    They should fire the guy that designed that safety disconnect switch. :rolleyes:
     
  6. Erik Kleiva

    Erik Kleiva New Member

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    Five
    It's actually a bulletproof design.
     
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  7. christian cox

    christian cox Member

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    Vehicle:
    2005 Prius
    Model:
    Base
    I just did the swap too . It wasn’t too labor intensive but now it just starts and then stops. I ran a diagnostic and I get a cam sensor code. I swapped the sensors from the original Engine which only had head gasket issues and still the same issue. It turns over for like 7 seconds then stops. And when I reset it by pulling the main fuse connector and HV battery fuse connector orange tab it still says check hybrid system?? What am I doing wrong? I’m starting to suspect the engine timing might be off?? Any ideas anyone??
     
  8. christian cox

    christian cox Member

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    I just did the swap too . It wasn’t too labor intensive but now it just starts and then stops. I ran a diagnostic and I get a cam sensor code. I swapped the sensors from the original Engine which only had head gasket issues and still the same issue. It turns over for like 7 seconds then stops. And when I reset it by pulling the main fuse connector and HV battery fuse connector orange tab it still says check hybrid system?? What am I doing wrong? I’m starting to suspect the engine timing might be off?? Any ideas anyone?? Before I do something useless and costly. This is my Uber car and I NEED to back on the toad. Any help will be immensely appreciateD
     
  9. Erik Kleiva

    Erik Kleiva New Member

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    2012 Prius v wagon
    Model:
    Five
    have you used Techstream or another obdII code reader?
     
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  10. christian cox

    christian cox Member

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    Vehicle:
    2005 Prius
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    Base
    Yeah I use the general code reader it came back with the cam sensor knock sensor temperature sensor water pump and maf sensor which all are on the left side of the wire harness that makes me wonder if there wasn’t some kind of wire rip or something but I inspected the wire harness and I don’t see anything. And I don’t have text stream I don’t know how to get it I do have a laptop if anybody can give me instruction on that I appreciate it very much.
     
  11. SFO

    SFO Senior Member

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    There is a sub that covers OBD2 stuff, but you'll also need a cable to use techstream. Many will buy a 'mini-vci' cable (20ish), but there are better cable options as well. Installation instructions are plentiful on the web, and there are preinstalled turnkey VM's as well.
     
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  12. christian cox

    christian cox Member

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    I got the techstream v16. and did the health check it came back with a p261b error water pump code . So I changed water pump but still got the same code. I found on you tube there’s a specific pump they recommended . In pic below. Otherwise the engine runs fine. Also I called around to find a garage near me that did retrofits and haven’t found one yet. I’m in Cincinnati I guess they’re not too hip here but I’ll keep looking. I was thinking it might possibly be the ecm may need an update but who knows ? Lastly still considering using a standalone water pump controller that uses PWM just like the Toyota ecm does. It looks pretty good it’s called a Davies Craig controller you would never have to worry if the pump was a certain model number it would run any pump as long as it fits. It follows the temps and keeps circulation for hot spots and very good reviews from everyone. I think it beats taking the engine back out and swapping heads from old gen 3 engine. Trial and error see how it goes.
     

    Attached Files:

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  13. Noeylicious

    Noeylicious Junior Member

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    is the techstream software free?
     
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  14. Tombukt2

    Tombukt2 Senior Member

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    I've had the Craig Davies electric pump set up on other vehicles many years ago worked very well but I didn't need it on many things I had it on
     
  15. douglasjre

    douglasjre Senior Member

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    Toyota leases it from a vendor. We buy hacked versions that give us unlocking ability without the actual password on eBay. You can get the latest version 16 for about a dozen dollars and then for under 50 bucks you can get an MVI module with an exhorse driver. This is the gold standard for how to fix any Toyota Scion or Lexus. People might think they're favorite Bluetooth dongle for a song and a dance off flebe is all they need but it's crap compared to this complete software package. This is how repairs need to be done
     
  16. Carlos De Castro

    Carlos De Castro New Member

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    Three
    Is there any way I could request a video on how exactly all the hoses line up on a 4th gen egr to the 3rd gen chassy? I'm trying to read the diagram but I'm more of a visual type of guy...
     
  17. Mendel Leisk

    Mendel Leisk Luddite

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    @Ragingfit might do one?
     
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  18. Carlos De Castro

    Carlos De Castro New Member

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    I'll check it out thanks
     
  19. Carlos De Castro

    Carlos De Castro New Member

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    Three
    oh this guy... ya I watched his videos.... he's using the 3rd gen egr... I think I'll just cut the threads like him and just use the third gen..
     
  20. zinzet

    zinzet Junior Member

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    Hi everyone. I've found good engine from Prius Prime 2021. Does anyone know will it fit for gen 3?
     
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