Interior lights went on headlights went out

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by thomassster, Oct 12, 2022.

  1. thomassster

    thomassster Member

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    Vehicle:
    2019 Prius
    Model:
    XLE AWD-e
    Strangest thing occurred. My car is a 2019 XLE awde, keep car in garage, and probably only 30,000 miles. While driving home at night, my headlights shut off and my interior dome lights went on. This occurred for about 15 seconds until headlights went on and interior lights turned off. Within a 5 mile ride, this happened twice. Any idea what it could be? I verified front interior light switch is set to middle, back interior light setting is set to light on when door opens, and headlights set to auto.
     
    #1 thomassster, Oct 12, 2022
  2. CooCooCaChoo

    CooCooCaChoo Senior Member

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    Very strange indeed. Was there a loss of power to the drivetrain? What about the dash board? The car give any warning signs on the little screens?
     
    #2 CooCooCaChoo, Oct 13, 2022
  3. thomassster

    thomassster Member

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    XLE AWD-e
    Radio was still on. No drivetrain issues, but I did startle me, so my senses was in reaction mode of making sure I don’t crash into anything. Dashboard appeared fine. I did not monitor the headlight indicator though. So im not sure what the state of that was. I had two toddler kids crying in the back so my mind was not fully ready for diagnosing the moment it occurred.
     
    #3 thomassster, Oct 13, 2022
  4. Doug McC

    Doug McC Senior Member

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    XLE
    Two things: With headlight switch set in auto lights would stay on, if the power switch was shut off, until either the timer timed out or the door was opened (depending on how you have things set up); if the power switch was shut off the dome light would come on AND the headlights would stay on (see above).
    So what ever happened SHOULD NOT HAVE HAPPENED.
    Time to get the car to a dealership that knows what they are doing. The safety of your kids and you are at stake and all the long distance troubleshooting ideas aren’t worth the risk. JMHO
     
    #4 Doug McC, Oct 14, 2022
  5. Doug McC

    Doug McC Senior Member

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    My wife just asked “did the kids open the door?”. That might explain it. If they did time to flip that back door switch to prevent that problem from recurring.
     
    #5 Doug McC, Oct 14, 2022
  6. thomassster

    thomassster Member

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    Vehicle:
    2019 Prius
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    XLE AWD-e
    So far, I have not able to duplicate the situation. Cause of that, I don’t know if the dealership would help resolve my issue with the data that I know which is limited. The kids are in car seats and the child lock is enabled so they can’t open the back doors.

    I don’t know if there is any relations, but sometimes my after market head unit randomly shuts off for like 10 seconds and then comes back on. This probably happens about once every 3 months. I verified all the wiring is soldered, no crimps. I don’t know if there is any relations to it. I personally think is a flakey pioneer head unit.
     
    #6 thomassster, Oct 19, 2022
    Doug McC likes this.
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