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Check Engine Light

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by priusjunky, Sep 10, 2011.

  1. priusjunky

    priusjunky Junior Member

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    The check engine light came on yesterday. 2004 with 115K. Auto Zone read the codes and they are as follows:
    Definition:
    Idle Air Control Valve control circuit.
    Probable Cause:
    Open or short circuit condition.
    Poor Electrical Connection
    Failed IAC motor

    Any idea where the idle air control valve is located under the hood? I'd like to check for loose or open connections.
    The right rear brake light is also intermittent, but I don't think the two are related.

    All suggestions are welcome.

    Lou
     
    #1 priusjunky, Sep 10, 2011
  2. jdenenberg

    jdenenberg EE Professor

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    Give us the numerical codes. AutoZone's computer sometimes misinterprets Prius codes.

    JeffD
     
    #2 jdenenberg, Sep 10, 2011
  3. priusjunky

    priusjunky Junior Member

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    P0505 is the OEM #

    Lou
     
    #3 priusjunky, Sep 10, 2011
  4. seilerts

    seilerts Battery Curmudgeon

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    Prii don't have IACV -- thank God.

    More likely that you have a vacuum leak, a throttle plate stuck open partially, poorly connected PCV hose, or MAF sensor problem.

    Suggested step:

    1. Buy a can of MAF cleaner at same parts store and clean the MAF sensor.
    2. Battery negative disconnect for 5 minutes.
    3. If no joy, proceed to cleaning throttle body, buy can of throttle body cleaner at same parts store.
    4. Battery negative disconnect for 5 minutes.
    5. If no joy, replace PCV valve and hose.
    6. Battery negative disconnect for 5 minutes.
    7. If no joy, take to dealer.
     
    #4 seilerts, Sep 10, 2011
    1 person likes this.
  5. priusjunky

    priusjunky Junior Member

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    Thanks, not to good with abbreviations, will look them up. Where is the MAF sensor located. I am assuming that the throttle body is accessible under the air filter, PVC valve should be easy to find.

    Thanks again

    Lou
     
    #5 priusjunky, Sep 10, 2011
  6. seilerts

    seilerts Battery Curmudgeon

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    MAF, mass air flow, is attached to the black plastic air intake with two Phillips screws.
     
    #6 seilerts, Sep 11, 2011
  7. jdenenberg

    jdenenberg EE Professor

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    #7 jdenenberg, Sep 11, 2011
  8. priusjunky

    priusjunky Junior Member

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    Thanks, I'll give that a try. Is there a fuse I can pull that will reset the code, instead of pulling the cable on the battery?

    Lou
     
    #8 priusjunky, Sep 11, 2011
  9. priusjunky

    priusjunky Junior Member

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    #9 priusjunky, Sep 12, 2011
  10. seilerts

    seilerts Battery Curmudgeon

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    Just so you know, some emission codes don't cause the light to come on until two "trips" have been completed. So you may find it lighting up in a day or two.
     
    #10 seilerts, Sep 12, 2011
  11. priusjunky

    priusjunky Junior Member

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    Not sure what the definition of a "trip" is, but so far so good.

    Lou
     
    #11 priusjunky, Sep 14, 2011
  12. priusjunky

    priusjunky Junior Member

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    It has been a week and the light remains off..Thanks again to all, for the forum and help.

    Lou
     
    #12 priusjunky, Sep 17, 2011
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