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Red triangle but good mpg

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Dahvid, Aug 30, 2024.

  1. rjparker

    rjparker Tu Humilde Sirviente

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    Codes IMG_6324.jpeg IMG_6325.jpeg
    IMG_6326.jpeg
     
  2. Dahvid

    Dahvid Junior Member

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    Given the amount of corrosion and lack of any visual evidence of leaking, could it be a short in the wires that connect to the relay? I'm just thinking out loud and doing some cursory searches on YouTube to find out more.

    Thanks
     
  3. mr_guy_mann

    mr_guy_mann Senior Member

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    After you did a "system scan" with the autel, did you select "HV battery" system and go into that part of the menu?

    If you were in the ECM - engine section, that would explain the data you retrieved and the lack of freezeframe.

    Posted via the PriusChat mobile app.
     
  4. Dahvid

    Dahvid Junior Member

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    No nothing shows up in the freeze frame and I've still not received a response from their support. I'm just probably found to end up returning the Autel honestly. If someone did not post the build 8 file here I wouldn't even have been able to run a full scan bc of it.

    I think I'm going to get a new wire harness and bus bars and hopefully that will fix the issue. There was evidence that the corrosion got on to the harness. By the looks of the fan no one has ever been in there to service anything including that disgusting fan.
    I'm definitely a convert since picking up this prius on Craigslist. Love the mpg. Can't wait to do the suspension work on it to make it a great daily car.

    Thanks again to everyone for their input I greatly appreciate it
     
  5. ChapmanF

    ChapmanF Senior Member

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    If the whole Techstream/scan-tool headache is about getting INF codes for P0AA6, you could just imitate what gen 1 Prius owners had to do, since gen 1 didn't give those INF codes for you. You can still kinda do the same thing in a later gen. See this post.
     
  6. ColoradoCrow

    ColoradoCrow Active Member

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    I've replaced the suspension on two 2008 Prius I went with the KYB Strut plus systems. Do the backs first. then the fronts take your time. Clean everything as you go. Also. I would highly recommend lifting the Prius with an Off Road kit from Prius Off Road in Cali. It gives 1.25" of much loved lift. I never take mine off road....but scraped all the time on roads, driveways and entrances and exits everywhere. no loss in MPG. It still puts a smile on my face when I no longer scrape everywhere. It doesn't make your Prius a 4x4 truck. more like a subaru outback...just enough to drive normally and not scrape and damage your car anymore. Moving forward.I would put that lift on ANY and EVERY Prius I will own. Customer service was awesome. I ordered the kit and it was shipped out to me in 4:25 minutes. I had a email with shipping and tracking info. Best $350 I've spent on my Prius.
     
  7. Dahvid

    Dahvid Junior Member

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    I would like to do stuff like this. I've heard great things about prius off road and look forward to getting some of their products. Just trying to get the battery situation resolved
     
  8. Dahvid

    Dahvid Junior Member

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    So can someone tell me which harnesses that I should be looking at or how many there are?

    I've found listings on ebay that have just the wires and those that look like that have wires and the plastic bus bar piece.

    I'm not trying to throw parts at it but is there a way to know if the harness is the problem? Again I've found evidence of corrosion reaching parts of the harness but would be nice if I could somehow substantiate that.


    This looks like the entire kit is that right? Looks like it has the temp sensors too idk if I need that

    PRIUS 04 - 09 HV BATTERY WIRE HARNESS G9240 47020 A | eBay

    This is just the long plastic bus bar holder with the wires already together

    04-09 PRIUS BATTERY WIRE FRAME NO.2 82165-47040 GENUINE TOYOTA | eBay

    This is the cheapest option I see. It's just the wires no long plastic piece. I imagine it would be a little more work to put this into my existing plastic piece but it is worth it?

    Hybrid Battery Harness, Compatible with Toyota PRIUS Gen II (2004-2009) | eBay

    Attached is also a diagram from one of the listings

    Are the harnesses the same for both the rear facing vs the front face of the battery? Most of the corrosion is on the rear facing side of the battery so I'm thinking of starting there.


    Could the problem just be the corrosion on the bus bars? I plan on changing those anyway while I'm in there but could that be causing the isolation fault?
    Your input is greatly appreciated!
     

    Attached Files:

    #68 Dahvid, Oct 8, 2024
    Last edited: Oct 8, 2024
  9. ChapmanF

    ChapmanF Senior Member

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    Do you know yet whether you should be looking in the battery or in some other area of the car?

    If you don't, you can find out, whether or not you have a scan tool that can show you the INF codes. If you do, you can use those. If you don't, see post #58 or #65.
     
  10. Brian1954

    Brian1954 Senior Member

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    See post # 59. INF codes 526 and 612.
     
  11. ChapmanF

    ChapmanF Senior Member

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    Ah, missed that one. My bad.
     
  12. Dahvid

    Dahvid Junior Member

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    Something I noticed since last getting into the battery last week.

    My mpg had dropped from mid 40s to now mid 30s.

    It's only been less than half a tank but I noticed the resistance in Dr prius on cell 8 and 9 is greater

    Could that be somehow effecting my mpgs? Anything else that it could be? Just thought it was odd since I was tinkering back there my mpgs would drop.
    My driving has been mostly city with decent city traffic. Before I had some occasional highway mileage but still majority city driving
    Thanks

    Attached is the resistance I'm noticing and the other is before I went back there
     

    Attached Files:

  13. Dahvid

    Dahvid Junior Member

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    Just another update.

    So I left the quarter panels out from the hatch interior when I was inspecting the battery. Where the courtesy light would.be there is a hard plastic piece that the removed interior piece would join to.

    After some cursory searches it looks to be pretty common I guess. Here's a yt video that shows where the cracks form. I'll have to check myself to see if that's the case for me.

    The big question would be if this is causing the p0aa6 error

    There's a insulating foam behind that hard plastic trim I was describing earlier and when I touched it it was soaked. I could squeeze it like a sponge. I haven't pulled up the hatch floor or the spare tire tray but I'm thinking water is pooling somewhere causing the isolation fault or maybe more likely it's dripping along one of the many wire harnesses some of which involve the hybrid battery.

    For what it's worth the passenger side where the 12v battery is I did notice some dampness but nothing like the passenger side. Would water dripping on the 12v cause the error?

    I should mention it's been very dry in my area and I mostly park in the garage. Yesterday was the first day I was actually driving in moderate rain since getting the car a couple of months ago.

    Your thoughts are greatly appreciated.
     
  14. Brian1954

    Brian1954 Senior Member

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    No, water dripping on the 12v battery will not cause a P0AA6 trouble code.
     
  15. Dahvid

    Dahvid Junior Member

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    So most of the water/ dampness was on the drivers side opposite the 12v battery.

    I'm guessing that's where the fault is coming from

    I peeled back those two plastic pieces that run along the roof and noticed what I believe to be small cracks which I guess is common on gen 2.

    I'm going to apply some sealant on those areas and see if I still get that dampness.

    It's been dry where I'm at and I usually park in a garage so it might be tricky to see if this works.

    Any thoughts on how to test this? I guess I could use a water hose or get a car wash and see if the water still is finding a way in.

    Could it be that water is making it's way in then dripping down a wire or harness?

    I still have part of the interior rear quarter panels removed in the hatch and that's where I discovered the water ingress.