2015 Prius suddenly showing "Check hybrid system" and not staying on

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by eezybeezy, Feb 17, 2026 at 5:56 PM.

  1. eezybeezy

    eezybeezy Junior Member

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    2015 Prius
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    I have a 2015 Prius Gen 3.

    My car has been running fine up till now. Today, I went out to start my car. It started but the Check hybrid system message came up on the dash, and the engine shut off before too long. Each time I started it, the engine would shut off faster, until it was only took about a second the third or fourth time.

    I think this is potentially related to my 12V battery. A couple weeks ago, it got below freezing and I didn't start my car for about a week. When I went to start it, the battery was dead. I jumped it, but I had an issue where I had to jump it again a few days later, even after starting it once a day after that.

    I checked the OBD codes today after the issue and all of these were on:

    Might this all be fixed with a new 12V battery?
     
    #1 eezybeezy, Feb 17, 2026 at 5:56 PM
  2. ChapmanF

    ChapmanF Senior Member

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    If you think it might be, maybe first give the battery you've got a good charge, clear the codes, and see if they come back. If they don't, you might be on to something.

    If they do, you probably really do have an issue in the throttle motor circuit. The P2118 is the reason there's a P0A0F, which is the reason there are C1259 and C1310. The car isn't going to let the engine keep running if it can't control the throttle.

    The B232x codes will be their own different thing. If those come back, you might want to look around for evidence of uninvited guests nibbling on your wiring.
     
    #2 ChapmanF, Feb 17, 2026 at 7:39 PM
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  3. Eddie25

    Eddie25 Active Member

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    Basic battery test (charge, jump pack, etc.) then... Put gas in it. Do NOT trust the gauge. Gauge is known to stick, fooling people and throwing mostly the same codes (ask me how I know). If you know FOR A FACT that you recently got gas, you can trust yourself, but otherwise put gas in it.

    It's likely the car is not actually "starting" it's attempting to start and failing. Attempts to start use the hybrid battery and can last around 10 seconds but the gas engine won't 'catch'. Take care to not 'waste' attempts without having a solid diagnostic plan because the hybrid battery will only allow so many start attempts before it needs charged (may already be at that point).
     
    #3 Eddie25, Feb 18, 2026 at 11:33 PM
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  4. eezybeezy

    eezybeezy Junior Member

    Joined:
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    Vehicle:
    2015 Prius
    Model:
    Four
    I tested the voltage of the battery after sitting for a bit and it was at 6V. I tried charging it to start the car with a jump pack, but I couldn't get it to start still. It got up to 11.5V while charging.

    I'm almost positive there's gas in the car.

    I think the battery got ruined during the cold, so I ordered a new one.
     
    #4 eezybeezy, Feb 19, 2026 at 12:05 AM
    Brian1954 likes this.
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