check hybrid system light came on

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by bobby515, Nov 25, 2025 at 2:05 PM.

  1. bobby515

    bobby515 Member

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    On my way home today, my check hybrid system light came on. I hooked my my basic cheap Bluetooth scanner.
    I was wondering what codes came up as I was on the way home. I hit clear. They went away. The Car is safely parked.
    Seems like the engine had a smell and was hotter than normal. 240k on it, new OEM water pump. My inverter flow was never able to see if it was running. I think maybe the pump could be bad. I want to get a more advanced code reader tool to check the car out. Any idea. Rebuilt 6 months 6-month-old. 100% don't think it's the battery, as it charges and discharges properly to me.
    Any advice. And what's a basic better black friday code reader to get? Going to load test the regular battery.
    I think it's an inverter or pump..just guessing..new headgasket 1 year..
    I put 60k on the car in 2 years...
    If the inverter is bad, is eBay bad for a used one? Thanks in advance
     
    #1 bobby515, Nov 25, 2025 at 2:05 PM
  2. ChapmanF

    ChapmanF Senior Member

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    There are about 200 reasons for "check hybrid system", so if you want to guess you have to be very good at guessing.
     
    #2 ChapmanF, Nov 25, 2025 at 2:36 PM
  3. bobby515

    bobby515 Member

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    Is thier a scanner tool i could be to.narrow it down.??
    Any ideas where to start. I have tools and experience. Just the hybrid is difficult for me.
     
    #3 bobby515, Nov 25, 2025 at 3:11 PM
  4. bobby515

    bobby515 Member

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    Question on a gen 3. Invertor plastic tank. With the car running is the fluid supposed to be flowing while car is running. Mine never has. .
     
    #4 bobby515, Nov 25, 2025 at 3:19 PM
  5. ChapmanF

    ChapmanF Senior Member

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    Gen 1 and gen 2 used a single-speed pump that's always on whenever the car is IG ON or READY.

    Gen 3 has a pump that runs at variable speed as needed for cooling. So it's harder to check just by looking at fluid in the reservoir.

    As there are around 200 different trouble codes that can give the warning you've got, best next step is to read the trouble code(s). Then you'll know whether the pump even has anything to do with the code(s) present.
     
    #5 ChapmanF, Nov 25, 2025 at 3:28 PM
  6. bobby515

    bobby515 Member

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    Can you recommend a black friday code reader that will give me more info or the type I need. I got the basic cheap $15 Bluetooth one.
     
    #6 bobby515, Nov 25, 2025 at 3:50 PM
  7. ChapmanF

    ChapmanF Senior Member

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    Autel AP200 gets pretty good talk around here. I have one and it does the job. I wish it did not require signing in to their cloud (thus requiring an internet connection) every week or so. After you do that, it will keep working for a week or so even if you're on the road with no internet, but I'm sure some day I'll leave on a road trip without remembering to sign in first, and then need it on the side of the road somewhere and it'll say "signin needed". (n)

    Other than that it's pretty great.
     
    #7 ChapmanF, Nov 25, 2025 at 4:28 PM
    Brian1954 and PriusCamper like this.
  8. Brian1954

    Brian1954 Senior Member

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    The Autel AP200 is my recommendation. It can communicate with all 18 or so ECUs in a Gen 3 Prius. What that means is that it is capable of reading all the trouble codes, not just some of them. It can do everything that the Toyota Techstream software can do. The price right now on Amazon is $49.99 + tax. I own this model, and I also have Techstream.

    The following two linked threads are good reading.
    https://priuschat.com/index.php?posts/3248209

    Read post #1 and then scroll down to post #37 in this thread, https://priuschat.com/index.php?posts/3246758
     
    #8 Brian1954, Nov 25, 2025 at 6:50 PM
  9. bobby515

    bobby515 Member

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    I posted on here yesterday about the hybrid check engine light on. With a basic code reader, i removed it car was ok. Came on again I reset it.
    I brought a rebuilt battery, it went bad in only... they game me another one.
    While being stumped all night. Thinking maybe inverter or something else and ordering a better scan tool, I remembered i got the Dr. Pruis app.
    I did test today to see if the battery was ok. Test is bad, 33.3% capacity left it says at the end of life, weak block 8.
    Before buying a rebuilt battery, I got some used cells on eBay and installed them. Was better. But later on, I treated myself to a rebuilt battery.
    My question is. I will put in pictures at the bottom.
    Can I last a few weeks like this?
    I can take out and battery apart. Should I just replace 2 cells in #8 block? Happy Thanksgiving, thanks for reading.
    you guys think i will get stuck..i can put cells in myself sunday..advice
     

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    #9 bobby515, Nov 26, 2025 at 9:06 AM
  10. ChapmanF

    ChapmanF Senior Member

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    Have you found out why the check hybrid light is on, yet, or are you just assuming that because of the Dr Prius battery life report, that must be what the car wans to tell you about?

    You haven't included any screenshot where Dr Prius shows you trouble codes. I believe it is able to show some trouble codes. It can only show codes from a small fraction of the ECUs in the car, and it miscategorizes some, but it may well show you the codes that apply here.
     
    #10 ChapmanF, Nov 26, 2025 at 10:05 AM
  11. bobby515

    bobby515 Member

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    Screenshot_20251126_074457_Torque (3).jpg
     

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    #11 bobby515, Nov 26, 2025 at 11:59 AM
  12. Tideland Prius

    Tideland Prius Moderator of the North
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    Threads merged
     
    #12 Tideland Prius, Nov 26, 2025 at 5:17 PM
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