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Possible to determine CEL code myself?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by HerkyHawk, Sep 30, 2006.

  1. HerkyHawk

    HerkyHawk New Member

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    I apologize if this topic has been covered, but I did a search and did not find this addressed (hopefully I didn't miss is).

    The CEL came on in my 5-week-old 2006 Prius yesterday. I checked the gas cap and it was on tight, but I took it off and on again just to be sure. The two Toyota dealerships near me (45 miles north and 55 miles south) are booked for a week. This is our family's only car and both grown ups work, so taking it to the dealer on a weekday will take some planning.

    Is there any way I can determine the error code myself? I would like to try to figure out if it's something potentially small or big before I drive it any great distance.

    Any suggestions? Thanks in advance - I really appreciate all of the help (and helpful people) on this board.
     
    #1 HerkyHawk, Sep 30, 2006
  2. efusco

    efusco Moderator Emeritus
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    Drive it just a little longer, a couple more start stop cycles. If it was the gas cap the CEL will usually clear after 3 startup cycles.

    I haven't heard about it being reported since the early '04 Prii, but there was some crud in the system that would have to 'burn out' but would trigger a CEL. They usually just recommended driving at highway speed for a while to burn if off and the CEL would eventually clear on it's own.

    Finally, you can try a Pep Boys type place, they'll often allow you to check the codes with their machine....then you can come back here with the codes and someone will let you know what it means.
     
    #2 efusco, Sep 30, 2006
  3. jdenenberg

    jdenenberg EE Professor

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    <div class='quotetop'>QUOTE(efusco @ Sep 30 2006, 09:26 AM) [snapback]325989[/snapback]</div>
    AutoZone will check it for free if their ODBII unit handles the CAN protocol.

    JeffD
     
    #3 jdenenberg, Sep 30, 2006
  4. HerkyHawk

    HerkyHawk New Member

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    Thanks much, to both of you. We have an AutoZone and a Napa in town. I will give them a call. I haven't driven the car out of town in a few weeks, so perhaps that is contributing to this, too?
     
    #4 HerkyHawk, Sep 30, 2006
  5. HerkyHawk

    HerkyHawk New Member

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    Okay, I have an update. I haven't been able to take the car to a Toyota dealership/service center yet, but the CEL light went off Thursday. I had been driving primarily in town and not at very high speeds or for any great length of time when the light went on. Thursday, I had to do a 110-mile roundtrip on the interstate and the CEL went off on the way back (probably about 15 engine starts since the light came on).

    Here is what I find interesting: while the light was on I got the lowest mileage I've had since getting the car. This was only the third tank of gas. I was getting in the low-to-mid-30s. As soon as the CEL light went off (same tank of gas), my mileage immediately improved - dramatically (about 10 MPG right away). Does this sound familiar to anyone? Any ideas as to why this might happen?

    I have an appointment next Saturday and I may keep it just to get the error codes. I did take the car to an Advanced Auto Parts and they were unable to get a reading on their ODBII. The guy wasn't sure what I meant when I asked, "Can it handle the CAN protocol?" so I'm not sure if that was the issue there. He did say it was the newest ODB they could get.

    Thanks :D
     
    #5 HerkyHawk, Oct 8, 2006
  6. galaxee

    galaxee mostly benevolent

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    an obdii scanner won't get ya much from the prius. it sucks, but that's the way it is.

    lots of things can cause a check engine light and decrease gas mileage. usually when the cel is on, the car isn't operating at peak efficiency. all you can do is find out what's causing the light to come on- if the codes are still stored in memory.
     
    #6 galaxee, Oct 8, 2006
  7. hdrygas

    hdrygas New Member

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    <div class='quotetop'>QUOTE(HerkyHawk @ Sep 30 2006, 05:32 AM) [snapback]325976[/snapback]</div>
    To answer the question you need two things. First a scanner that will down load the DTC (diagnostic trouble codes), second a copy of the service manual for your car. You can download that at http://techinfo.toyota.com/index.html . It will cost you 10 bucks a day, or you can order the printed manual and that is very expensive put you have it under you hand when you need it. Entire diagnostic procedures are outlined in the service manual. I think that the burn off thing with the early 04's was solved by the time I bought my car in August of 04.
     
    #7 hdrygas, Oct 8, 2006
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