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Check Engine Light came on in the rain.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Wuvo, Oct 5, 2017.

  1. Wuvo

    Wuvo New Member

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    Hey guys,

    I picked up a 2015 Prius with approximately 53,000 miles on it. Will post more details (and maybe some sort of intro in another thread...)

    I was driving home from work yesterday - IN THE RAIN - in the check engine light came on. The light remained on today. I plan on getting the codes this evening and should know more then... However, searching doesn't reveal this to be a common trend.

    So, prior to getting the codes, does anyone have any idea what might be causing this? (I imagine some sensor got wet and angry...)

    Thanks!
     
  2. xliderider

    xliderider Senior Member

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    Not much use speculating, get the codes and update this thread.

    It could be anything, like a loose gas cap.

    Till then, welcome to PriusChat. :)

    Posted via the PriusChat mobile app.
     
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  3. JC91006

    JC91006 Senior Member

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    Check your gas cap, make sure it's on correctly
     
  4. tankyuong

    tankyuong Senior Member

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    goto auto parts store to read code
     
  5. Prodigyplace

    Prodigyplace Senior Member

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    If they cannot read a code, you may need the dealer to read it. Auto parts store readers cannot detect some Prius-specific codes.
     
  6. Wuvo

    Wuvo New Member

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    Oh, man, I didn't think I actually posted this thread before getting the codes, but I had a "first message" award waiting.

    It was an O2 sensor, probably just got wet. I reset the code and the light has stayed off. I'll wait to see what happens during the next rain.
     
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  7. exstudent

    exstudent Senior Member

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    You should have NOT cleared the code, if it was truly the O2 sensor.

    O2 sensor(s) are usu considered to be emission components, and are usu covered by the longer Emission Warranty. Your State might be 8yr/100K mile; look at your Warranty Manual to verify.

    Also, anything other than miniVCI w/Techstream software will NOT READ ALL the Prius codes; this is what the Toyota delaers use. Their are too many instances of junk OBD2 readers reporting innacurate codes, non-existant codes, and no codes despite warning lights being displayed.

    It costs very little to get miniVCI w/ Techstream; $20-$30 @ Amazon of crapBay (eBay). Best paired to an obsolete Windows 32bit laptop (XP/7), for ease of use and malware concerns. The fee to have a dealer read the codes varies on location and dealer; expect to pay minimum of $100.
     
  8. Prodigyplace

    Prodigyplace Senior Member

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    It only costs very little is you are unconcerned about a legal software license.
     
  9. exstudent

    exstudent Senior Member

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    If you are using the hacked Techstream software, we are in the same boat; and the pot calls the kettle black.

    If you are not, then you are a BETTER person, then me and the many others who are.

    If Toyota would make the software more affordable, say upto $400/version, then I would buy the genuine, or maybe even like the cirrent Adobe and Microsoft subscription pricing model.
     
  10. Wuvo

    Wuvo New Member

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    I cleared the code because it was likely brought on by the rain and wanted to see if it would illuminate again after driving.

    Fairly certain a standard OBD-II scanner will easily and accurately detect most common errors, specifically one of the oxygen sensors on the Prius. I would make the bold assumption a standard OBD-II scanner is ill equipped for the HSD-centric error codes, but more than apt at most "common" errors. OBD-II is a standard only, but O2 sensors are standard equipment, eh?
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    That can feel good, but might be leading you into a misdiagnosis. Starting with the rain: I wouldn't assume rain tripped something.
     
  12. Wuvo

    Wuvo New Member

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    We're going to go in circles, I think. :D :D (The assumption is about OBD-II standards, though, not the rain.)

    I'm 100% confident the CEL came on in the rain. (Correlation =/= causation, though...) I'm *fairly* confident water brought on the CEL by possibly interrupting the loop in some manner we're probably familiar with; short/open, out of tolerance down/upstream variance... etc. I'm also relatively sure the O2 sensors on the Prius are all wire-vented to the atmosphere, which allows for a remote - albeit possible - chance water can enter the sensor interface.

    I could be wrong - I certainly don't want to come off as a know it all - but these subjects are well with in the arena of my professional expertise, and while the Prius is unique in some ways, the O2 sensor here is relegated to standard duties not unlike "normal" vehicles, which gives me a pretty high confidence in the OBD-II results.

    Having said that, I'm probably going to be wrong. :) (I also did not think I actually posted this topic...)
     
  13. Raytheeagle

    Raytheeagle Senior Member

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    You married, cause you sound well trained:whistle:.
     
  14. exstudent

    exstudent Senior Member

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    Too funny.
     
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