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Red triangle on, no check engine light, engine not charging hv battery, decelerating charges battery

Discussion in 'Gen 2 Prius Main Forum' started by John Bach1, Dec 21, 2021.

  1. John Bach1

    John Bach1 Junior Member

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    Location:
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    Vehicle:
    2004 Prius
    Model:
    Base
    04 Prius Starts and drives normally. Lost communication symbol on screen. Red triangle appeared while driving.
     
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Do you have any OBD2 codes (DTCs) that are worth posting?

    FYI : you're being moderated until you've posted 5 times.
     
  3. John Bach1

    John Bach1 Junior Member

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    OBD2 shows no stored or pending codes.
     
  4. nancytheprius

    nancytheprius Active Member

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    What code reader did you use? probably need a better one or techstream
     
  5. John Bach1

    John Bach1 Junior Member

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    Harbor Freight. I don't have a Techstream. I checked fuses but found none burned out. Restarted engine now and red triangle gone. Engine now charging hv battery normally. Car running perfectly again. Any guesses as to what it could have been?
     
  6. SFO

    SFO Senior Member

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    Generally speaking, when the red triangle appears (or other warning lights) there will be OBD2 codes (DTCs) stored in the ECUs.

    Try taking the vehicle to all of the surrounding auto parts chain stores (autozone, oriellys, pepboys, aap) for a 'free code scan', each location (even within the same chain) may offer a different scanner, and if you're lucky, one may actually have a toyota hybrid compatible scanner.

    Once you have the OBD2 codes handy, post them here for additional guidance. When was the last time you checked the oil level?
     
  7. John Bach1

    John Bach1 Junior Member

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    Vehicle:
    2004 Prius
    Model:
    Base
    Funny you asked about that. A few months ago the red triangle of death appeared. I checked the oil level and it was very low. I added oil and the triangle was gone. This time the other day the oil was a little low (but in the correct range) and I added some oil. The triangle appeared 2 days later so that the oil level wasn't the issue. Now that everything is normal (no triangle and engine charging the hv battery again) I'm assuming the problem has resolved itself. I did not clear the codes with my HF scanner since there were no stored or pending codes to clear.