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P0AFA & P3000 after replacing hybrid Battery. Looks like battery ECU has corrosion

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by hoosierprius81, Nov 14, 2021.

  1. hoosierprius81

    hoosierprius81 Junior Member

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    I had the red triangle of death, other lights and like 25 codes related to certain banks of the hybrid battery being low, and the car would intermittently not want to accelerate (very scary the first time it happened on the road). All I could afford was a used/refurbished battery (yes, I know this is not a long term fix).
    I replaced the battery with the new modules yesterday. I made sure to torque all bolts to Toyota specs. I started up the car and still had the triangle but now instead of 25 or so codes, I only had 2 (P0AFA & P3000). I took out the hybrid battery ECU and this is it:

    IMG_7673.jpeg IMG_7674.jpeg
    My question is, would this little corrosion on a few pins still cause the red triangle and the two codes? It seems the other photos I see on here of other bad hybrid battery ECU's have a lot more corrosion or even have pins missing. I tried looking at the connector and I couldn't see any corrosion. Should I also replace the bus bar that plugs into the hybrid battery ECU? Where should I look for another ECU? Toyota wants over $600.
     
    #1 hoosierprius81, Nov 14, 2021
    Last edited: Nov 14, 2021
  2. ChapmanF

    ChapmanF Senior Member

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    If we're good, will you tell us what the codes are?
     
    #2 ChapmanF, Nov 14, 2021
    hoosierprius81 and SFO like this.
  3. hoosierprius81

    hoosierprius81 Junior Member

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    Oh haha, I put them in the title but not the body. They are P0AFA and P3000.
     
    #3 hoosierprius81, Nov 14, 2021
  4. ChapmanF

    ChapmanF Senior Member

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    I think when you're saying "HV ECU" you mean the battery ECU (the HV ECU is up under the dash).

    You've got one code from each; the P3000 is just the HV ECU saying "hmm, the battery ECU is reporting some kind of weirdness, have you talked to him?", and the P0AFA is the battery ECU saying "umm, yeah, I'm getting these weird voltage readings from the modules", so that's definitely related to the connection there. It would be interesting to pull up what the 14 readings are showing up as.
     
    #4 ChapmanF, Nov 14, 2021
  5. hoosierprius81

    hoosierprius81 Junior Member

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    Yes, you are correct. My apologies. I have updated my post. When you say "pull up the 14 readings" are you referring to reading the voltage through a reader like the Dr. Prius app?
     
    #5 hoosierprius81, Nov 14, 2021
  6. ChapmanF

    ChapmanF Senior Member

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    Affirmative.
     
    #6 ChapmanF, Nov 14, 2021
  7. hoosierprius81

    hoosierprius81 Junior Member

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    I do not have a Dr. Prius compatible reader. Do you think it would be worth getting one or is replacing the hybrid battery ECU pretty much the only next step?
     
    #7 hoosierprius81, Nov 14, 2021
  8. ChapmanF

    ChapmanF Senior Member

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    Many people will get a dongle that can be used with a phone app like Dr. Prius or, perhaps even better, one that will work with a laptop and Techstream, because it can be so helpful so many times to be able to see what your car is telling you.

    Otherwise, if you are absolutely sure the voltage sense wiring can't possibly be the problem, then the ECU would be the other thing that's left. If I had Techstream or Dr. Prius, I would be looking at the readings just to double check my absolutely sures and my can't possiblys.
     
    #8 ChapmanF, Nov 14, 2021
  9. hoosierprius81

    hoosierprius81 Junior Member

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    I see. So if I got a dongle for Dr. Prius or Techstream, what would I want to look at and how would I have a better understanding of if its is the ECU or the wiring?
     
    #9 hoosierprius81, Nov 14, 2021
  10. ChapmanF

    ChapmanF Senior Member

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    I would be looking at exactly what the ECU says it is reading on each of the 14 inputs.

    Then I could combine that information with extra careful physical inspection of the wires, especially the ones involved in weird readings. Maybe take some readings of my own with a meter I trust and compare to what the ECU says it is seeing. I'm sure you can think of variations along those lines.

    The question boils down to, does the ECU think reading x is weird voltage y because weird y really is arriving at the ECU on that input, or is it getting sane voltage v and misreading it?
     
    #10 ChapmanF, Nov 14, 2021
  11. Tombukt2

    Tombukt2 Senior Member

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    Top 3 from right look discolored white ashy look to them ? Right in picture. Junk yard have all ya want to remove.

    SM-A715F ?
     
    #11 Tombukt2, Nov 16, 2021
  12. ChapmanF

    ChapmanF Senior Member

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    That's the sort of thing that almost makes you want to look at the voltage readings to see whether there are weird ones that correspond to the top three pins from right, or if the weird ones are different ones.
     
    #12 ChapmanF, Nov 16, 2021
  13. mr_guy_mann

    mr_guy_mann Senior Member

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    There you go being all logical again, (must be a character flaw ). Don't you know that testing requires EFFORT and reading and all that... stuff.

    Much "better" (ie simpler) to load up the parts cannon and fire away. The target HAS to be somewhere between the front and rear bumpers. They'll hit the target- eventually.

    Posted via the PriusChat mobile app.
     
    #13 mr_guy_mann, Nov 16, 2021
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