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  1. Larry Newman

    Larry Newman Junior Member

    Joined:
    May 18, 2021
    6
    1
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    Location:
    Orlando, Fl
    Vehicle:
    2008 Prius
    Model:
    Touring
    I have a 2008 Prius Touring that recently was the blessed recipient of a red triangle, VSC warning light, and brake warning light on the dashboard. Upon hooking into Techstream, further information revealed that the code was a P0AA6 isolation fault with subcode 612. I took the back of the car apart, battery out, etc. Upon inspection, I didn't see any obviously leaking modules or major issues. Everything looks to be in pristine condition except the bus bar bolts/connectors between battery cells. I looked around the forums and other websites for a couple hours to see if I could pinpoint a non-obvious 612, but I couldn't really find anything.

    I have attached pictures of the case, components, and battery cells. I have two leads after tinkering around with forum posts and a multimeter for 2-3 hours. I only attached one picture of the battery cells to avoid having to flip them over (my back is killing me after taking everything apart and sitting on a concrete floor). The bottoms of the battery cells are also in pristine condition; I checked all sides of every cell thoroughly twice to see if there was a leak without anything standing out.

    Lead #1 - If you see in the attached pictures of the case, there are some spots in the case. Compared to the other pictures of leaking batteries I've seen while researching, this doesn't look like cells leaking; it's also more evenly distributed throughout the entire length of the case so I would assume it's dirt or condensation spots or something else. Not really sure if this could still be cells leaking but if anyone has seen something like this, I would be very appreciative if you pointed it out.

    Lead #2 - I used a diagram file on another post I found while researching on where to use a multimeter to determine if there's a short on any of the connections. Everything was normal except for the resistance of the ground wire to some of the connections to the bus bar (the metal links meant to connect cells together). The diagram indicated that >10 ohms was the standard resistance, but I was seeing about half of that. The other connections were very close or over 10 ohms.

    Besides these two leads, I have precisely nothing that I can go off of other than replacing the battery cells and seeing if that fixes the issue. From what I've gathered from poking around, I'm open to replacing the battery cells (open to keeping the car as long as possible) and also cleaning the bus bar connections. My main desire for putting this out in the open is for some validation to ensure I'm not overlooking something obvious or something simple. I could always clean the bus bar connections or get a new cable then reassemble and see if it fixes it, but I'd like input on it first because I'm still a novice at the HV system.

    Any input is appreciated. Thanks.
     

    Attached Files:

  2. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
    9,703
    1,697
    0
    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    So you used your DVO hammer test meter to measure from ground to the bottom of every module that takes those little tiny screws since you've unracked this business I usually check this while it's all together put a test lead to ground and test one of the hybrid battery plug fuse sides. And see if the DVOM will count down to zero on the DC volt scale that should when you have this fault it will not and somewhere there's a leak and then while it's all racked up I leave the ground set up like it is and flip the battery up on it side and go down with the red lead and touch every one of those I don't know what is it 56 screws or something those little tiny bolts any of them that get a reading market with a black sharpie marker that's a problem. It looks like I see some spatter on your tray there those dark brown spots or whatever they got there somehow.