Hybrid battery started discharging/charging quickly, the got Red Triangle warning light

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by ItsWheels, Jan 1, 2021.

  1. ItsWheels

    ItsWheels Junior Member

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    Hello all, so i've got a 2006 Prius for about 3 months already, but when i was driving from work today i noticed the hybrid battery started discharging very quickly to just 1 purple bar and charging very quickly all the way up to full, then i got the red triangle light, followed by the check engine light and the (!) symbol and i have a car with a ! mark on my MFD.
    I continued my journey to home, and when i was parking i had my engine turned off with 4 blue bars on my MFD but the car was still gaining charge till it was full?? Like, what is happening here?
    I searched many, many topics on this forum but i couldn't find none talking about something like this.
    I appreciate all the help/opinions you guys can give me about this weird thing that is happening.
    If you guys need more information, just ask me and i will post it.
    Thanks!!
     
    #1 ItsWheels, Jan 1, 2021
  2. mr_guy_mann

    mr_guy_mann Senior Member

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    It sounds like your high voltage battery is failing. I would suggest getting an app like Dr Prius or Hybrid Assistant with a comptible OBD2 adapter to check the hybrid system for codes. Basically if the hv battery goes out then the car won't move. This is a very common scenario on this forum.

    IF that's the problem then you need to decide what you want/can do. Options are: sell/scrap the car, buy a new set of modules, get a "rebuilt" battery, or repair it yourself.

    You could pay Toyota lots to replace it or buy a new set of battery modules from Toyota or from Newpriusbatteries.com and install them yourself. Buy a "rebuilt" (USED) battery(which WILL go bad- how long of a warranty??) , have someone replace the bad modules with used ones(which WILL go bad) , replace the bad ones yourself (just replace with a complete used set from a junkyard, or replace a few and then perform charge/discharge cycling with external chargers).

    There are lots of options that can cover a wide range of costs and predicted reliabilty. New - costs the most but is basically worry free for years. Replacing a few modules and nothing else is cheapest but has very high chance of failing again in a few weeks or days. Other options are in between; less money = more time to repair and/or less reliable. There are lots of posts on this forum concerning this.

    So get what you need to pull codes, then start doing some research and make some descisions.

    Posted via the PriusChat mobile app.
     
    #2 mr_guy_mann, Jan 2, 2021
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  3. ItsWheels

    ItsWheels Junior Member

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    Thank you so much for you answer!

    I see, so the best thing i can do for now is to check my hybrid battery health just to make sure it can be the culprit in here.
    I tested today my 12v battery with the car turned off, sitting by 1 day, and it was marking 11.80v, and with the ignition on was something like 12.01v, is this any good? Can it be the thing that is faling in here?
    I don't know if this is the correct thing to do, but i disconnect the big white connector from the black fuse box to "reset" my Prius, then i started it, and it was working normally again without any error lights, but then something like 2-3 minutes after driving it, the red triangle light appeared again. Battery discharching and charging quickly, but the car was running "perfectly fine".

    The things is, i bought the car just now, and im very afraid it might need a new hybrid battery (it has now 118k miles).

    I have a OEM Toyota 12v battery, do you think it might be the original one still?

    I just ordered a MINI VCI so, let's see if this is gonna help me by any chance pulling any codes.

    Thank you for the help you gave me again!
     
    #3 ItsWheels, Jan 2, 2021
  4. SFO

    SFO Senior Member

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    Many like to use a "mini-vci" cable and techstream (dealer technician software) to scan for OBD2 codes (DTCs), othes get by with just a simple OBD2 bluetooth adapter and one of the Apps mentioned above.

    Before buying an OBD2 adapter, first read up and find a quality product : Hybrid battery diagnostic and repair tool for Toyota and Lexus
     
    #4 SFO, Jan 2, 2021
  5. ItsWheels

    ItsWheels Junior Member

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    Thank you for your anwser!

    I searched for many OBD2 bluetooth scanners, but in the end i just ordered a mini-vci because i think it's the best one to give you the specific Toyota DTCs, and as you said techstream is a dealer software! And i was here thinking it was some "cheap" software just to scan some generic codes hehe.

    So yeah, now i will just wait for it to arrive and let's see what is going on here.

    Fingers crossed it isn't the hybrid battery going bad on me now!
     
    #5 ItsWheels, Jan 2, 2021
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  6. edthefox5

    edthefox5 Senior Member

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    12 volt battery is bad too.
     
    #6 edthefox5, Jan 3, 2021
  7. edthefox5

    edthefox5 Senior Member

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    You never posted miles on the car but if it has more than 150000 the engine probably eats a lot of oil. You need to find out how much. Always keep the oil at the full line and check it at least every week before the car is started in the morning for the accurate level. If it eats oil I would move up to 40 weight oil.
     
    #7 edthefox5, Jan 3, 2021
  8. mr_guy_mann

    mr_guy_mann Senior Member

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    From your description the 12V battery is no good (should be 12.6 to 12.8V fully charged- after sitting with nothing on the car turned on).

    When you disconnect the 12V, you reset the HV battery ecu and it takes a few minutes of running before it determines that there is a problem and gives a RTOD. When you get your mini VCI you can pull the exact codes, but you may want assume that you have one or more bad modules in the pack and do research accordingly.

    At this point I wouldn't trust the car - it could leave you stranded at any point.

    Posted via the PriusChat mobile app.
     
    #8 mr_guy_mann, Jan 3, 2021
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