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Tail light, turn signal and hazards issue

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by QB_one, Dec 26, 2021.

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  1. QB_one

    QB_one Junior Member

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    No tail light, no license plate light, no rear fog light, no parking light, but headlights and braking lights works fine. When I turn on turn signal (left or right), hazards come on! Light indicator on dashboard lits, but no lights outside.
    Yesterday I changed brake pads, and after starting a car VSC/ABS/brake warnings appeared, ABS was not working. I tried clear the issue by disconnecting 12V battery, didn't work. Then I find procedure with connecting two pins on OBD connector and depressing brake pedal 8 times.... It cleared the error and brake/ABS workes fine. I'm not sure if lights issue is appear immediate after this operation (it was daytime, and no need to use turn signals for some time), but at dusk I notice the issue. No faults stored in ECU...

    I tried to disconnect 12V battery again and left if disconnected over night, didn't helped :(

    Any idea? I assume that body ECU needs reset, but don't know how to do it?
     
    #1 QB_one, Dec 26, 2021
  2. dolj

    dolj Senior Member

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    Why are you assuming an ECU is faulty? It sounds more like an electrical issue. Painstasking methodical tracing using the wiring diagram as reference is the best way to deal with this.
     
    #2 dolj, Dec 26, 2021
  3. ChapmanF

    ChapmanF Senior Member

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    If you did that without first writing down which trouble codes were blinked when you connected those pins, then you have set yourself back on whatever the brake issue was, and will have to wait until the next time it is detected and the codes are available again so you can make further progress solving it.

    On the taillight, turn, and hazards issue, from the story so far, I am inclined to agree with dolj that some kind of wiring damage sounds likely; in any case, something that methodical tracing with a multimeter and the wiring diagram will lead you to.
     
    #3 ChapmanF, Dec 27, 2021
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