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Thread: checksum fail -Cant Read the ECU we have contacted HP support but no reply yet

  1. #1
    Potential Tuner
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    Apr 2021
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    checksum fail -Cant Read the ECU we have contacted HP support but no reply yet

    2004 GMC 1500 had a v6 4.3
    Someone put a 5.3 from a yukon on and the ecu to match.

    Cannot even read the ecu we get a "Checksum Fail" half way through reading.. we tried grabbing a couple of tunes off the forum to force through to see if that did anything but it wont allow it to write.. we dont want to waste a bunch of credits.

    Anyone have any ideas?

  2. #2
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    Sep 2020
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    Following... Having the same issue with a 411
    Chancellor B Rowland

  3. #3
    HP Tuners Support
    (foff667)
    Bill@HPTuners's Avatar
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    Have the ecm flashed to stock via tech 2 or similar oem style flash device and try reading again. Sounds like your ecm is corrupt to me.
    It doesn't have to be perfect, it just needs to be done in two weeks...

    A wise man once said "google it"