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Check Engine Light and Codes Help Needed

Discussion in 'Generation 1 Prius Discussion' started by Linda L, Mar 6, 2014.

  1. Linda L

    Linda L Junior Member

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    2002 Prius
    Last weekend, it was brutally cold (at least for Texas standards) when I got gas. I could not get the gas cap to click,and being only a couple of blocks from home, I drove it home thinking I would fix it later when my hands were warmer. Well, I forgot and headed to the "big" city on Monday, and the check engine light came on after driving 15-20 miles. Car was running fine, I assumed it was from the gas cap being loose (which I fixed) and drove it home. It's run fine since Monday, and I drove it back to the "city" today and got codes read at Autozone.
    It showed code P0420 Catalyst system efficiency below threshold Bank 1, P0301 cylinder 1 misfire detected, and a C-1259 HV System Regenerative malfunction.
    I had the Hybrid battery replaced at the dealership (with a new one) last October, and the car (2002) has just over 160k miles.
    Can you help me figure out what is going on and how to proceed?

    Linda
     
  2. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Did they reset the codes and, did the codes come back right away?

    The misfire code is likely a stored code but, have you had the sparkplugs replaced? I'm thinking the p0420 could be from a loose gas cap.

    If it were me, I would double check the gas cap, clear the codes, drive it and see if they come back. I think in this case, there's a good chance they wont come back.
     
  3. Linda L

    Linda L Junior Member

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    They would not clear codes. Said it was against policy.
     
  4. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Ok, how many times have you cycled the ignition on and off since you tightened the gas cap? Usually four cycles of the ignition with no codes will clear the Master warning light and five cycles with no codes will clear the check engine light. Notice I say usually.
     
  5. Linda L

    Linda L Junior Member

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    Way more than four or five. At least that many times a day since Monday, although they were shorter trips if that matters.
     
  6. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Darn,
    Unfortunately you will have to get the codes reset or you can do it yourself. This can be done by momentarily (about a min) diconnecting the negative cable of the 12V battery. Do you feel comfortable doing this?

    The reason to do this is to ensure you have a "recurring" code. If the code comes back, you read it again then go from there. My experience with the Gen I is that codes periodically come up but don't always come back. The consistent recurrence of a code indicates a problem that must be dealt with.
     
  7. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    The other option is to bring it to a dealer but, do you know a reliable, trustworthy dealer? Or you can take it to and independent mechanic that works on hybrids.
     
  8. Linda L

    Linda L Junior Member

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    I think I can handle disconnecting the negative cable. My dealer is reliable, though I am not sure I'd use the word trustworthy. They tried to charge me $500 over MSRP for the hybrid battery, and when I called them on it, they told me it was customary dealer markup. Needless to say, I got the battery at MSRP, but only because I knew the MSRP thanks to this board, and argued it.
     
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  9. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Yeah then, I would go ahead and disconnect the neg cable and see if the codes come back (either right away or within a week or so). Chances are, they will not but we want to be sure. If they do come back they will need to be read again and we can come up with a plan to get you back to driving a car without codes. I forgot to ask you if there are any drivability issues (does it drive normally and get the same mpg your used to)? I'm guessing there are none.
     
  10. Linda L

    Linda L Junior Member

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    Car seems to drive fine. MPG is normal. It did idle rough for a few seconds a couple of days ago (a day or two after the check engine light came on).
     
  11. Linda L

    Linda L Junior Member

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    Interesting development. During my 60 mile drive home from a track meet late last night, the check engine light went out on its own. So I am thinking that the longer drive again yesterday might have convinced the car that it was operating fine again. Or maybe the fact that four days had passed with it working fine? Who knows? I am just happy the light went out on its own. Thanks for all your help, usnavystgc.
     
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  12. usnavystgc

    usnavystgc Die Hard DIYer and Ebike enthusiast.

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    Yep, this kind of thing is very common. Glad to hear it and happy I could help. :)