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Resetting Check engine light

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by Hoc, May 2, 2024.

  1. Hoc

    Hoc New Member

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    Vehicle:
    2013 Prius c
    Model:
    One
    Hi guys! First time trying to diagnose a car here. I have a 2013 prius C which just been to maintenance at 80k miles. A few weeks later I got a check engine light on. I was informed that I could use a OBD2 to check what the warnings are, so I bought one and see p0441 and p0455 codes. Looking up the codes and see it’s usually about the tank cap which I already tried tighten before using obd2 but it didn’t turn off the light. One of the guide I found just tighten the cap and clear the codes. So I did the same. I looked at the cap and don’t see any cracks.
    My question is that when I clear a codes, would it reappear if the problem persist? In my case if the problem wasn’t the tank cap, would the check engine light show up again? I’m just wondering if I actually fixed it or I’m just ignoring a problem that could cause future damage
     
    #1 Hoc, May 2, 2024
  2. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Pennsylvania
    Vehicle:
    2018 Prius c
    Model:
    Two
    These errors relate to the evaporative emissions control system. Basically all the stuff that prevents your gasoline supply from evaporating away on a warm day.

    The bad news: this is a very complex system and there's a long list of potential causes for those two codes.

    The good news: even when it is all broken, it doesn't affect the way the car drives.

    It might prevent you from passing an annual inspection if that is a thing where you live.

    It can be as simple as a bad o-ring on the gas cap, or a rotted or mouse-eaten vacuum hose up under the hood somewhere.

    Sometimes they don't figure it out until somebody hooks the car up to a smoke machine- you blow theatrical smoke into the vacuum system and pay attention to where it comes out.

    Usually when you reset an evaporative code without actually repairing the car it takes a while to come back, but certain failure types can be detected immediately and would re-fail immediately.

    Because the list of possibilities is so long, it really is worth renting the factory service manual and stepping through it. Or pay a shop to do it.

    Good luck!
     
    #2 Leadfoot J. McCoalroller, May 2, 2024
  3. Hoc

    Hoc New Member

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    2013 Prius c
    Model:
    One
    Thank you for your the answer! The links will come in handy as I plan to start doing more DIY repairs.
     
    #3 Hoc, May 2, 2024
  4. Carall

    Carall Member

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    Apr 22, 2023
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    Location:
    Harrisonburg, VA
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    2012 Prius
    Model:
    V
    I've recently fixed the same problem on a 2015 Prius С. It looks like some kind of animal has chewed on the pipe.
     

    Attached Files:

    #4 Carall, May 5, 2024
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