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Too many Error codes! 05 Prius

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by JPAWN89, Jun 21, 2018.

  1. JPAWN89

    JPAWN89 New Member

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    So first time ever posting something, but have been using Prius Chat for all my previous Prius fixes. My Prius has well over 200,000mi on it since I commute about 120mi 4 days out of 7.

    So all of a sudden pretty much all of lights have come on. When I say everything I mean EVERYTHING!! I have an OTC CodeConnect w/ ABS & Airbag reader ( which I acquired for free during my last deployment (^.^)d ). The codes I have gotten are the following:

    P0420 - Most likely an O2 sensor going bad
    P0A93 - Inverter Coolant Pump already ordered and awaiting delivery
    P0A80 - Also getting P3019 and P03020 which means that cell module 9 and 10 are weak, but after disassembling it I found that cell module 19 is weak with a volt meter. The rest of my modules read 7.8, so I ordered 1 cell to replace the bad one which read 6.5

    I believe these are the major codes needing immediate attention and hopefully erase all the other codes which I will list down below.
    P0A08 - Assuming this will go away once the Inverter Coolant Pump gets replaced

    P3000
    P3102
    C1241 - Assuming ALL of these will go away once the bad cell gets replaced and the HV battery is back
    C1259
    C1310

    Any clarification would be HIGHLY appreciated... Thanks in advance!!
     
  2. dolj

    dolj Senior Member

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    It sounds like you may not having a complete understanding of cells, modules and blocks as used in Techstream.

    P3019 and P03020 actually means that blocks 9 and 10 are weak, not modules 9 and 10.

    On PriusChat we use this terminology to keep communication good and misunderstanding low:
    • Cells: are the smallest unit of the battery. The Gen 2 contains 168 cells.
    • Modules: are the smallest workable unit. The Gen 2 has 28 modules comprising 6 cells. These cells cannot practically be accessed.
    • Blocks: are pairs of modules and are the smallest unit monitored by the HV battery ECU. The Gen 2 Prius has 14 blocks.

    Just to re-iterate, in the Gen 2, modules and blocks are counted from the right side of the battery (the opposite end from where the electrics/electronics are) to the left side (the end where the electrics/electronics are). I think you have this correct.

    Techstream is telling you that block 9 (modules 17 & 18) and block 10 (modules 19 & 20) are weak. You might find one or both of the modules are actually weak. Your OCV test will only find any module with at least 1 dead cell, but not much more. Techstream is telling you that at least 2 of the 4 modules in blocks 9 & 10 are not performing within spec. So, I'd be load testing* all other modules and replacing any others that were suspect as shown by load testing. If you get more than 6 that are suspect, I'd be looking at replacing all with new (or newer i.e. < 5 yo) modules. The approach you take depends on how much time you have, how much money you have to throw at this, whether you want the repair to last 10 years or are happy for less and want to rinse and repeat. I'm told, that after pulling the battery for the third time to remediate, the novelty has well and truly worn off.

    Hope that helps.



    *Load testing procedure: ProlongĀ® Battery Module Load Tester User Guide. Note the tester to which this link refers, can easily be built if you're handy.
     
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  3. JC91006

    JC91006 Senior Member

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    You're looking at replacing at least 3 items

    1. Catalytic converter
    2. Hybrid battery
    3. Inverter pump

    And your engine might be burning lots of oil
     
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  4. ChapmanF

    ChapmanF Senior Member

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    OP has the right idea on the P0420 ... the fortune cookie for that code may have the word "catalyst" in it, but it would be premature to throw a cat at it before tracing the detection condition to a cause.

    -Chap
     
  5. JC91006

    JC91006 Senior Member

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    An 05 with over 200k miles will most likely have a CAT failure.......

    But if you're not in California, O2 sensor or aftermarket CAT won't break the bank. It's the hv battery that will cause problems
     
  6. JPAWN89

    JPAWN89 New Member

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    All my parts should be getting shipped by tomorrow minus the CAT. Hopefully things will be a bit better after I replace the 1 module I was able to identify as being low (6.5) and replacing the pump.
    Is there a way to test whether its the O2 sensor or the CAT thats bad?

    Also, appreciate the correction on the terminology! I can finally understand the conversation about the HV battery a bit better now.