Need help diagnosing - inconsistent low voltage codes after replacing modules

Discussion in 'Gen 2 Prius Technical Discussion' started by josh.0, Oct 22, 2021.

  1. josh.0

    josh.0 New Member

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    2008 Prius
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    I bought a 2008 Prius with 110k about three months ago, and have put 5k on it since, mostly highway. Red triangle came on a few times during that period, the guy I bought it from (who repairs and sells used Priuses from his property) explained that I could clear the triangle by disconnecting the 12v. So I did that a number of times, probably a total of a dozen over that 5k miles, before it finally went into limp mode and I knew I had a bigger problem. I then invested in a VEEPEAK OBDII scanner, downloaded Dr Prius app, and watched several youtube videos. Ordered a few modules off eBay, and went to work.

    After removing the battery and identifying the faulty module with a multimeter (in block 13 of course), I replaced it and began reassembling. At this time, I realized that I needed a new wiring harness (see pic 1) - much of the plastic had been melted (I immediately messaged the seller and he informed me that was existing when I bought it), and I had broken a soldered connection while moving the pack around.

    I ordered and installed the new wiring harness. While I was reassembling the battery pack, I had trouble getting the modules in place to receive the mounting bolts and foolishly angled a few in, stripping several and even breaking a few in the process. I was able to get them all in place though, as well as the plastic plate on the end, and so I moved forward.

    I re-installed the battery in the car and was able to start it with no issues. I drove no more than 15 minutes before getting a red triangle, showing p3000 and another code that a block was low. I cleared the code and continued driving for another 15 minutes before the same thing happened again (p3000 plus another code, this time with a different block being low). This pattern continued, always with p3000 and always with a different block showing as low.I figured the loose (stripped) and missing mounting bolts were the problem, and ordered replacements.

    I have since properly mounted all modules, but am having the same problem. p3000 + a different low block. All blocks usually read above 16v on Dr Prius at the time I get the red triangle, and the block that shows the lowest on the graph does not always correspond with the thrown code (ex: block 1 reads the lowest on the graph, but the code is p3020 = block 10). There are a series of pictures showing the graph and corresponding codes, which don't match up, as you'll see). code translation: p3011 = block 1 is low, and they go up from there. So p3012 = block 2, p3020 = block 10, etc.)

    This has been consistent over many days now. I have cleared codes, disconnected the 12v, the same problems persist.

    Could it be the HV Ecu? All but one of the terminals look clean to me (see last pic), and the one is only slightly discolored. Could that be causing the inconsistent codes?

    OR

    Could it have anything to do with the mounting bolts connection? They are all firmly connected now, however, the frame of the pack itself is quite flimsy and I have had to bend and manipulate it a bit to get those holes to line up for the mounting bolts.

    All modules read at or above 7.62 with a multimeter. I am at a loss. And very frustrated.

    Thank you in advance!
     

    Attached Files:

  2. SFO

    SFO Senior Member

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    Welcome to PruisChat!!

    Best to let @TMR-JWAP handle this, as he is literally around your corner and up your block.

    Curious if the vehicle actually has 110k, that is quite low given the age. Did you run a carfax?

    FYI : your post are moderated until you've posted 5 times.
     
  3. TMR-JWAP

    TMR-JWAP Senior Member

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    The problem is the three missing nuts in the first photo...

    Just kidding around. (assuming you were in the middle of working on the battery when you took photos).

    If you're interested in throwing the car on Techstream to do a health check, let me know. I can help with that. Actually, I can probably help with just about anything on the car. If you click on my user name, the screen that pops up will have my contact info. I'm about a mile from Lake Murray Dam, on the Irmo side.
     
  4. srysoldout

    srysoldout New Member

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    Did this case ever get solved? I've got the same exact deal, p3000 p3016 p3018 etc. Replacing the wire harness in a few days from an old corroded one.
     
  5. TMR-JWAP

    TMR-JWAP Senior Member

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    never heard another peep......just crickets
     
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