1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Sudden red triangle with jerk- wiring harness corrosion?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by LKasdorf, Dec 9, 2022.

  1. LKasdorf

    LKasdorf Junior Member

    Joined:
    Aug 24, 2017
    67
    21
    1
    Location:
    Waterford, VA USA
    Vehicle:
    2007 Prius
    Model:
    II
    2005 prius with about 200k.
    In the last few days, the red triangle came on. Dr Prius shows 3rd bank is low (initially) and P3000 0a80 (I think that was it). Classic bad cell, I believe.
    The car still drove ok, even though the triangle was on. I can reset the battery err codes and lights go off. Car feels no different. I did this for a couple days- reset err, drive 50 mi, comes back on. No change in feel of car, and still gets same gas mileage (47).
    Yesterday- had to drive 82 mi. triangle came on towards the end. When starting the drive home, I cleared the code and drove fine. After 50 miles I was on a freeway and the triangle suddenly came on, and I felt a "clunk"- it was like I hit a bump in the road (but I didn't). I think the clunk was the sudden loss of electric motor drive.
    I was driving on the engine alone- info panel showed no lines to or from battery. A couple times I was able to get it reset and it drove better, but then it would happen again.
    So- I'm guessing corrosion on one of the cell connections in the harness. Maybe it has gotten intermittent. I guess it could be a bad cell, but it seems odd that it would be intermittent.
     
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
    23,073
    14,978
    0
    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    The car detects bad cells (well, really, it can only detect at the level of a block, twelve cells) by detecting changes in electrical behavior that will exceed its threshold under certain driving conditions, and it has to see that happen twice on separate trips before it is sure of the problem.

    When you clear the code and get some period of normal driving before the code and fail-safe behavior come back, that doesn't so much indicate a problem that's intermittent, as that you have given the car forced amnesia about the problem, which it then will not rediscover until the right driving conditions have met the right thresholds, again on two separate trips.
     
    Brian1954 likes this.
  3. LKasdorf

    LKasdorf Junior Member

    Joined:
    Aug 24, 2017
    67
    21
    1
    Location:
    Waterford, VA USA
    Vehicle:
    2007 Prius
    Model:
    II
    That is a really good explanation. I guess I'll pull the battery and look for weak cells, order "good" cells from ebay or amazon, reassemble and hope for the best. Rinse and repeat. And I'll bead blast the copper plates. I've done this at least 6 times on our 3 priuses- I'm growing weary... I wonder if there is an affordable lithium replacement yet?
    My wife thinks I should get a rebuilt pack with good warranty and have installed- and maybe that would make sense. But I know they employ used cells anyway, so I'm not too enthused.
     
  4. mr_guy_mann

    mr_guy_mann Senior Member

    Joined:
    Sep 3, 2020
    3,206
    1,338
    0
    Location:
    NJ-USA
    Vehicle:
    2006 Prius
    Model:
    Four
    Your HV battery pack is made up of 28 modules in series, grouped in 14 blocks of two modules. Each sealed module has six 1.2V cells, so "nominal" voltage is 6 x 1.2V x28 = 201.6V (at "full" charge it can be quite a bit higher than that).

    As ChapmanF mentioned, the ecu monitors the voltage of the 14 blocks and will set P0A80 code if the difference between the highest and lowest exceeds a programmed threshold for a certain amount of time. (more difference takes less time until it codes)

    That voltage difference usually shows up first under "heavy" charge or discharge (accel - decel). Depending on how bad it is, the ecu can either "just" set a code, or it can also go into "limp-in" mode (which really limits battery operation).

    Clearing the codes means the ecu "assumes" the battery is ok, until you drive enough for the weak module(s) to show up again. Eventually the car won't "ready up" anymore. OR there has been a couple threads about folks who kept clearing codes with a bad battery, and eventually had a (minor?) battery explosion.

    Posted via the PriusChat mobile app.
     
  5. alftoy

    alftoy Senior Member

    Joined:
    Mar 16, 2009
    1,130
    505
    0
    Location:
    Saskatchewan, Canada
    Vehicle:
    2008 Prius
    Model:
    Base
    Get a new lithium pack.

    https://projectlithium.com/?ref=9qLPw

    Or Hybrid Doctor Fredericksburg

    The Hybrid Doctor
     
  6. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    7,797
    1,349
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    The guy at the hybrid doctor in Fredericksburg is a great guy from South America He will hook you up if you can go to his place I did that it's 3 hours from my house heading towards my brother's house in DC It was well worth my trip and 650 bucks let me tell you instantaneously huge difference for my Gen 3 if I would have known about this guy when the Gen 2 was messing up I might have not bought a new battery at the time to give this a whirl for slightly less than half price He did a really good job or his employee did at the time I went to Fredericksburg the man himself was in an electric car show in Las Vegas I was dealing with his employees who barely speak English but know their work well and did a good job and we had a good time joking around my broken Spanish and they're broken English was a great afternoon good people.
     
  7. LKasdorf

    LKasdorf Junior Member

    Joined:
    Aug 24, 2017
    67
    21
    1
    Location:
    Waterford, VA USA
    Vehicle:
    2007 Prius
    Model:
    II
    Thanks for that info on hybrid doctor. I currently have the battery out of the car- I wonder if I can drive the battery to him and have them fix or swap it and return same day? I am about 2 1/4 hrs away.
     
  8. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    7,797
    1,349
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    If you call him the night before and tell him your situation he will be on standby when you arrive or one of his text well and they'll take your battery from you if you like and hand you one that's ready to go they'll even put it in a test vehicle sitting right in front of the shop and let you see it run and let you see the doctor Prius app while it's running and whatever else it is you'd like to do and talk about and then they'll set it in your trunk and you'll pay them whatever it is now and off you go or not All you got to do is call the guy he will hook you up Tell him you're from the Prius chat or you know Tom from North Carolina whatever good people
     
  9. LKasdorf

    LKasdorf Junior Member

    Joined:
    Aug 24, 2017
    67
    21
    1
    Location:
    Waterford, VA USA
    Vehicle:
    2007 Prius
    Model:
    II
    Thanks so much for pointing me to Hybrid doctor! I had them replace the batteries on all 3 of my Priuses. Excellent price - I got a bulk discount :)
    2 year warranty.