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Hybrid battery block voltage range

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Rizia, Jul 11, 2019.

  1. Rizia

    Rizia New Member

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    Hello,
    I recently got a Prius 2010 (131000 mileage) and today ran a diagnostic test at a Toyota service center. It shows to have a P0A80 ("Replace Hybrid Battery Pack") warning pending. Prius 2010 Hybrid battery diagnosis.jpg

    I was wondering,
    1. What is the range of voltage difference between these blocks for a hybrid system to work properly/show an error/malfunction?
    2. If for some reason the warning comes up, will I be able to start the car again? Or, drive the car safely back home /to a service center?

    I am considering just replacing one battery block and observe it for a month, but then again, I don't want to make things worse. I'd appreciate any suggestions/recommendations.
    Thank you.
     
  2. mjoo

    mjoo Senior Member

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    Your report doesn't prove which modules are bad. For that you need a load test.
     
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  3. Raytheeagle

    Raytheeagle Senior Member

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    What were the other codes associated with the P0A80? There will be another code as that one is just the generic one;).

    The voltages are not far enough out of line to require the modules to be replaced (at least off of the attached pic).

    Good luck and keep us posted (y).
     
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  4. TMR-JWAP

    TMR-JWAP Senior Member

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    One thing that stands out is the poor reading showing 10.99 volts for your 12v AGM style aux battery. You need to check/correct that before you waste time troubleshooting anything else. 10.99 volts on the 12v system, is asking for trouble and potentially going to cause a lot of tail chasing to nowhere. If the car was in ready mode when they took these readings, then you're in even more trouble because the inverter should have been putting 14.1ish onto the 12v system.

    I know for fact that once it gets down to around 9.5-10 volts, the dashboard icons will start flickering/flashing.

    Does your paperwork show anything for a "shortwave highest reading"? That's one of the measurements taken and displayed on techstream to show the condition of the HV system isolation from the rest of the car. A low value here will also code out. 5.00 volts is perfect, 0 volts is a dead short to the car body.

    You're also showing a subcode of 186 on the fourth set of readings. I don't remember what the 186 is.

    I do not know the accuracy of this chart, but it at least should give an idea of what you're working with.

    Battery-SOC.jpg
     
    #4 TMR-JWAP, Jul 12, 2019
    Last edited: Jul 12, 2019
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  5. TMR-JWAP

    TMR-JWAP Senior Member

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    ok, so I checked out my manual when I got home. A 186 subcode, as far as I know, only shows up under DTC P0A1D, which is Hybrid Powertrain Control Module/HV Control ECU internal error. Being that it appears only once in the recent memory, I wouldn't be too concerned about it. Also, considering you say the P0A80 is pending, I wouldn't get overly freaked out about that either. Pending just means it popped up once recently, but hasn't yet been backed up by another occurrence. IMO, get the 12v situation under control first, then see what happens.
     
  6. Grit

    Grit Senior Member

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    My packs are no more than .3 volts on average apart from each other. It could just be the 12v bat affecting the hv pack. One fella in here had the the dreaded code and swap the 12v, it fixed the problem.
     
    #6 Grit, Jul 12, 2019
    Last edited: Jul 12, 2019
  7. Heather03

    Heather03 Junior Member

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    Hope I'm posting in the right place!

    My used 2010 has 220k miles. This past winter I replaced my 12v battery after having some issues which seemed to solve everything I was experiencing.

    I've been getting the P0A80 code, 1 permanent and 1 pending since last year but car runs great. Had a guy put it on tech stream and he said I had 2 bad cells.

    I've recently been monitoring my voltages with torque (images attached). They seem to be within normal range, unless I'm not reading them properly?

    After resetting the code, it sometimes comes back after a couple days, and other times after a couple weeks. More often on high temperature/humid days.

    I have the solar roof panel option and the car came from Florida, had to clean out a lot of sand since purchasing. I'm wondering if the hybrid batteries need to just be cleaned?

    Please advise, any suggestions much appreciated!
     

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  8. TMR-JWAP

    TMR-JWAP Senior Member

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    With the block voltages that high, you are likely looking at them while they're being charged. That tends to cover up any low voltage conditions. Your best bet would be to check the voltages after the car has sat unused for a night or even over a weekend. A weak module should be much more obvious.

    The good thing about the P0A80 code is that it has freeze frame data. That data will show information captured at the instant the code occurred, including all block voltages. The bad part about it, is that FF data isn't always accessible using some code scanners or torque. If you know anyone with techstream, now would be a good time to invite them over for a beer....and have them bring their laptop :)
     
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  9. Heather03

    Heather03 Junior Member

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    I recently purchased a generic mini vci, guess it's time to figure that out and see if it works. Thanks for the expertise!
     
  10. TMR-JWAP

    TMR-JWAP Senior Member

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    Heather,

    You should be able to check those voltages using the torque app you have. You want to make sure the engine doesn't start and try to charge the HV battery though. You can do this by placing the car in Ignition-On mode. This will allow the OBD connection to work with the ECUs, yet it will not engage the HV Battery relays, which will prevent the engine from starting. Do this by pressing the power button 2 times with your foot NOT on the brake. That should allow you to look at the block voltages while the HV battery is at idle.

    Once you're done, press the power button one more time and the car will turn off. If you want to drive the car, then place your foot on the brake for the last button push and it will go to "ready" mode like normal.
     
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  11. bmwe46zhp

    bmwe46zhp Junior Member

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    And what should the volts ready to be considered a good working battery or range between the modules. Thanks
     
  12. bmwe46zhp

    bmwe46zhp Junior Member

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  13. iskoos

    iskoos Active Member

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    To the OP,
    That voltage difference between highest and lowest blocks is barely above 0.1volts
    It should be more than that and as others said the reading should be taken when the block voltages are low (like around the 13v level)
    I personally like to see at least 0.5volts difference to name a block as outlier.