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Check Engine Light

Discussion in 'Gen 2 Prius Main Forum' started by GeorgeMW, Apr 19, 2021.

  1. GeorgeMW

    GeorgeMW Junior Member

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    Hello, I'd like to know what all the causes for the Check Engine Light are for my gen 2. If there is a list somewhere on the internet, I hope you help me find it. Thank you for your time.
     
  2. mr_guy_mann

    mr_guy_mann Senior Member

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    The Check Engine light is mandated to illuminate when any fault occurs that could increase vehicle emissions to 1.5 times the federal limits. The light must flash if there is a cayalyst-damaging misfire or fuel trim fault present. All of the applicable diagnostic trouble codes (P series codes in the engine ecu) are listed in the factory service manual. In addition, Toyota decided to also turn on the light in the event that there are significant faults in other critical systems such as the hybrid drive - but without having any codes in the engine ecu.

    Posted via the PriusChat mobile app.
     
  3. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    TL ; DR
    If the light isn't flashing, it's likely not serious enough to engage a tow truck.
    The Simple Guide to The Check Engine Light


    You can read the codes for your car yourself by buying a $20 OBD-2 code reader.
    They're widely available in places like WalMart, Amazon, etc.
    You can get a $4000 code reader, but it will not be much better for your application than a $20 unit.
    The box it come with will have idiot-resistant instructions inside and there are a half million videos on the interwebs for how to use them.
    In YOUR car the port itself is a white squarish plug located under/behind your dash about where your brake pedal is.

    [​IMG]
    Once you get the code(s) you may determine whether it's something simple like a loose gas cap, or something much more severe like a cylinder missfire.


    If you're not much of a DIY'er, that's OK!
    Go to a place like AutoZone, Pep Boyz, etc....especially during a not-a-busy time and they will read the codes for you pretty much for free.....and often even give you good advice about next steps.

    Or?
    You can come back here.

    Do not go to the dealer.
    Avoid even driving BY the dealer!

    Good Luck!
     
  4. dolj

    dolj Senior Member

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    The list is too long to print here but all the codes are listed in the repair manual.

    It would be easier to just find out what codes are causing the light and then look them up in the repair manual which will give you the information to repair the problem.
     
  5. sam spade 2

    sam spade 2 Senior Member

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    Sorry but that is NOT a reasonable question to ask.
    There probably are close to a thousand different things that can cause that "general trouble" light to come on.
    You need a shop to do a "diagnostic" on it. Typical cost.....$75 to 150.
    A place like Auto Zone might do it for fee.
     
  6. ChapmanF

    ChapmanF Senior Member

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    One thing that can be worth remembering is that there are about a dozen different ECUs in your Gen 2, and the code scanner they are likely to have at AutoZone or Pep Boys, etc., will be able to query about two of them.

    Which means the technician might end up telling you "that's weird, you've got your light on but there aren't any codes." Or they'll say, for example, "we got a C1259 and a C1310", which are both codes in the brake system (which their scanner can read), and they both mean "hey, go look at the codes in your HV ECU" and you won't have those.

    We get a fair number of threads here that start "hey, I've got warning lights but no codes" or "what do I do to fix a C1259 and C1310?" for exactly those reasons.

    I feel the necessity of calling out this microaggression against trapezoids.
     
  7. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Fair nuff!

    Well I have a twitter and a Book of face account, but before you have me silenced by the Comité de salut public I'd like to point out that I haven't posted to either one in well over 5 years.

    I'm not cancel PROOF, but I'm highly resistant :D
     
    Moving Right Along likes this.