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EFI reset...When and why?

Discussion in '2nd Gen. Tacomas (2005-2015)' started by Bsfilter, Feb 4, 2012.

  1. Feb 4, 2012 at 8:25 PM
    #1
    Bsfilter

    Bsfilter [OP] Well-Known Member

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    I have seen in a few threads people suggesting an "EFI Reset" for one reason or another. I understand that to do so you simply disconnect the battery for a minute or so then the computer resets itself and the EFI as well. My question is why would a person need to do this? Is this something that should be done occasionally just for shits and giggles or is there a particular reason for doing so. Tried to search it to no avail.....
     
  2. Feb 4, 2012 at 8:26 PM
    #2
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Generally, its recomended to disconnect the negative battery conection when doing any work on the vehicle. However, most diso the terminal when doing some kid of performance mod to their truck. It helps the ECU to "re learn".
     
  3. Feb 4, 2012 at 8:30 PM
    #3
    Bsfilter

    Bsfilter [OP] Well-Known Member

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    Just changed the plugs and put the K&N back in. Should I do it? Seems to run great right now but if it could be better I'm all for it...
     
  4. Feb 4, 2012 at 8:31 PM
    #4
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Its gonna re learn regardless. I havent found too much difference from diso'ing it, as opposed to leaving it be. Some folks have noticed a difference though, so you might want to see if others respond.
     
  5. Feb 4, 2012 at 8:33 PM
    #5
    Bsfilter

    Bsfilter [OP] Well-Known Member

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    Thanks Chris! Think I will just well enough alone for the time being unless some compelling info shows up to change my mind...
     
  6. Feb 4, 2012 at 8:33 PM
    #6
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    ;)
     
  7. Feb 4, 2012 at 9:36 PM
    #7
    Fractured

    Fractured FPS-a-holic

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    The EFI fuse is one of the fuses for the ECU. We used to do it to clear CEL's, force the ECU to relearn, restart the readiness monitors, etc. without having to disconnect the battery because then the customers radio stations, clock etc. would be reset and at the dealership that is a big no-no :jerkoff:
     
  8. Feb 4, 2012 at 9:39 PM
    #8
    Fractured

    Fractured FPS-a-holic

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    Chris, you are correct. As soon as the ECU sees the short term and long term fuel trim change due to modifications to the fuel air system (if any) then it will adjust accordingly. Removing the EFI fuse will just force it do occur faster.

    It will also clear the readiness monitors though, and if that happens and they don't have a chance to fully run and you need to get your smog done, you will fail (in California- not sure about other states).
     
  9. Feb 4, 2012 at 9:43 PM
    #9
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Interesting. I knew you could pull the EFI fuse and have the same effect, but didnt know it made changes quicker when doing so. I may try that, and see how long it takes to have my fuel trims return to "normal" .
     
  10. Feb 4, 2012 at 9:49 PM
    #10
    Fractured

    Fractured FPS-a-holic

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    Chris,

    Short term fuel trim is changes being made in response to temporary conditions- like how you are presently driving. Long term fuel trim is used to modify fuel/air settings for things that seem to occur over a much longer period like a bad fuel injector, failing 02 sensor, vacuum leak etc.

    In essence it will restart your long term fuel trim from scratch- if you have a scangauge or something that you can monitor your data list values, make sure your long term fuel trim isn't higher than 10%!! That means there is an issue somewhere.
     
  11. Feb 5, 2012 at 7:28 AM
    #11
    chris4x4

    chris4x4 With sufficient thrust, pigs fly just fine. Moderator

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    Thank you. I know what the fuel trims represent. ;)
     
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