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Help me identify this issue? Likely a bad Hybrid Battery

Discussion in 'Gen 2 Prius Technical Discussion' started by mle70, Jun 20, 2020.

  1. mle70

    mle70 Junior Member

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    I’m guessing the hybrid is dying on our 2007 2nd gen. The other day the wife mentioned when she started it it had the “P-lock” message with the triangle “!” recommending the parking on a flat surface. While driving she mentioned it was feeling weak and sluggish. I read through some of these posts and was directed towards checking the 12v battery levels, it was low so i replaced it. While I was there the only code that came up when we ran the scan tool “p3191”. [​IMG] Then I cleaned the throttle body as well. The “P-lock” message is still there and the systems haven’t been effected. Today while test driving I heard the the rear passenger side fan on High (can’t say I remember hearing it before but it is 92 degrees today) the AC works well and is still very cold. Had it running the whole drive. I took it for a 10 mile drive today and it struggled to stay above 60. Then after about 5 miles in the city I basically had no acceleration and it creeped through the intersection. I pulled into a parking lot and powered off and luckily, it turned back on and seemed better but still pretty poor acceleration. Like I mentioned at the top seems like the hybrid battery is toast, but any suggestions to help better identify this?
     
    #1 mle70, Jun 20, 2020
  2. AzusaPrius

    AzusaPrius Senior Member

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    Do you think you can take apart the hybrid battery and work on it? You can test each module with it in the car as long as you take the orange safety plug out and take off the bus bar assembly. Find the lowest voltages and replace any in the 6 volt range.

    Posted via the PriusChat mobile app.
     
    #2 AzusaPrius, Jun 20, 2020
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  3. TMR-JWAP

    TMR-JWAP Senior Member

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    How about....before we go easter egg hunting, we actually get the codes read with something that understands hybrid codes. A p3191 code is "engine fails to start". Has nothing to do with a hybrid battery. Does the RTOD and fan often coincide with a P0A80 "replace hybrid battery" code? Yes, but they also trigger with about a thousand other codes.

    Now, does a P3191 make sense? Not really, if you were driving the car and the engine was running. So the suspicion is that the code reader you're using is likely not hybrid compatible. Step one is to get accurate information. Don't just go disassembling the HV battery on a wild-nice person guess. There are plenty of apps that can go on line with your Prius if you have a bluetooth device to plug into the OBD port. Or you can call around to various parts stores to see if they use a compatible reader. Or you can purchase a compatible reader. Or even rent one from autozone.
     
    #3 TMR-JWAP, Jun 20, 2020
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  4. mle70

    mle70 Junior Member

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    Thanks to both of you for your thoughts. After I read the first comment I watch some video of the process... yeeaaaahh I’m not going to do that until I get some more concrete evidence pointing in that direction. Although this would be a good opportunity to buy a OBD Bluetooth accessory, do you recommend any one specifically!?!

    With that being said, I do have an appt with a hybrid certified mechanic this week.
     
    #4 mle70, Jun 21, 2020
  5. bisco

    bisco cookie crumbler

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    dr. prius app can tell you a lot about the battery, but tech stream is the gold standard
     
    #5 bisco, Jun 21, 2020
  6. ChapmanF

    ChapmanF Senior Member

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    It could make more sense than you think. A Prius engine has to "start" more often than one in a conventional car, and some of the times when it starts are when you're already driving the car. And almost everybody is fooled by the sound of a Prius engine cranking (at like five times the RPM of a conventional engine cranked by a starter) into thinking it has already "started" when it hasn't.

    When my Gen 1 was having some engine issues I hadn't gotten around to fixing, I would often hop in, "start" it, pull out on the road, and get the P3191 several blocks later.

    There is a lot of diagnostic info in Prius ECUs that common readers have trouble reading. But a DTC isn't that kind of info. It is defined by a standard as a sixteen-bit number where you use the high two bits to choose P, C, B, or U and then show the rest as hexadecimal digits. A reader doesn't need to know anything special about a car to correctly print a DTC that way.
     
    #6 ChapmanF, Jun 21, 2020
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  7. mle70

    mle70 Junior Member

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    #7 mle70, Jun 23, 2020
  8. bisco

    bisco cookie crumbler

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    oh boy :(
     
    #8 bisco, Jun 23, 2020
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  9. mle70

    mle70 Junior Member

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    #9 mle70, Jun 23, 2020
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  10. strawbrad

    strawbrad http://minnesotahybridbatteries.com

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    With a battery replacement this car would run again. I suspect you have been ignoring a check engine light caused by the P0420, P0441, and P0455 codes for awhile. Those issues will not keep the car from running.
     
    #10 strawbrad, Jun 23, 2020
  11. mle70

    mle70 Junior Member

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    well, it’s not my car for daily use. The person That does use it regularly doesn’t notice those things that well. Now I realize I should have taken it to work with more regularity.

    I may research replacing just those cells though.
     
    #11 mle70, Jun 24, 2020
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  12. Jo-Jo Joseph Mims

    Jo-Jo Joseph Mims Junior Member

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    Yep...replace the bad cells and keep on rockin' or sell it cheep to me...after all, it needs a new battery, and that costs more than the car is worth... Where are you located?

    Posted via the PriusChat mobile app.
     
    #12 Jo-Jo Joseph Mims, Jun 27, 2020
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