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Thread: 06 gmc envoy p12 pcm issue

  1. #1
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    Default 06 gmc envoy p12 pcm issue

    i need help, read and saved the original tune. made a few changes, resaved it then linked back up the licence the pcm. next went to load file and now its telling me ''error, bootloader reject'', missing calibration file.
    at this point i cant re-read the pcm, load a file or anything. even if i check staus it says missing cali file. ive tried doing it on alt keys and low speed.

    what next?
    thx

  2. #2
    EFILive Developer Site Admin Blacky's Avatar
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    Quote Originally Posted by cyclerage View Post
    i need help, read and saved the original tune. made a few changes, resaved it then linked back up the licence the pcm. next went to load file and now its telling me ''error, bootloader reject'', missing calibration file.
    at this point i cant re-read the pcm, load a file or anything. even if i check staus it says missing cali file. ive tried doing it on alt keys and low speed.

    what next?
    thx
    Installed the latest software from here: https://www.efilive.com/index.php?op...=48&Itemid=133
    And try reading/flashing using the V8 software.

    Regards
    Paul
    Before asking for help, please read this.

  3. #3
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    I spoke with chuck cow earlier and he recommended the same. Hope it works. Thanks!

  4. #4
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    no luck, looks like pcm is dead. wont connect at all. V2 cant even show pcm details

  5. #5
    Lifetime Member Chevy366's Avatar
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    Disconnect the battery negative terminal (last resort), if the vehicle will start start it and then try again, don't know why the P12 acts up sometimes.
    Make sure and have the P12 PCM selected as the type of PCM (sometimes the V2 reverts to no PCM type).
    Have never had any trouble flashing any P12 other than you have to do a dance sometimes with key on and off.
    2005 1500 HD , Custom OS3 SD tune .
    2006 Trailblazer
    Dinosaurs and Plants gave their lives so that we may drive , long live fossil fuel .

  6. #6
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    i tried pulling the bat a few times, no change. the other day I was getting ( no clac file), today im getting no pcm found, no ses light (light for a few seconds but shuts off), stil wont crank, run, etc
    ive tried reading it with v7.5, calc flach & full flash. On v8 I tried reading & clac flash, wont evn give me the option to full flash on v8

  7. #7
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    ive checked all the fuses. I do have power at the aldl. I can pull all the codes from the other modules using just the V2, everything is non-comuncation codes from me clearing them the other day.
    am i correct in assuming the pcm needs to be reflashed with a tech2?

  8. #8
    Lifetime Member Chevy366's Avatar
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    Not necessarily, if you can get the V2 to communicate you can do a full flash of the old .tun and be fine.
    I had this happen one time, scared me, I did a key off, unhooked from the PCM and reconnected, got com and full flashed, everything was fine after that.
    Did you try a flash and it fail while flashing? I have recovered from that too, same thing disconnected from PCM key off, reconnected and got com, and full flashed, everything was fine.
    Odd it just wigged out after licensing of the PCM.
    2005 1500 HD , Custom OS3 SD tune .
    2006 Trailblazer
    Dinosaurs and Plants gave their lives so that we may drive , long live fossil fuel .

  9. #9
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    so, key off but leave the battery still hooked up and unplug the connextors from the pcm?

  10. #10
    Lifetime Member Chevy366's Avatar
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    Did you you do bootblock update when you updated, that can cause a cal error.
    No, do not take connections loose from PCM without taking negative terminal off first.
    I mean key off, disconnect the cable of the V2 then reattach the the V2 and key back on to the second position just before start.
    Then try and see if the Full Flash option is present.
    I have recovered from this before on a P12.
    2005 1500 HD , Custom OS3 SD tune .
    2006 Trailblazer
    Dinosaurs and Plants gave their lives so that we may drive , long live fossil fuel .

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