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Thread: Lly dead in the water.

  1. #1
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    Default Lly dead in the water.

    Tried getting a stock read off an 05 lly and got a communication error. Truck had no communication from ecm what so ever but everything else was reading. Customer had a spare ecm so we plugged it in and truck would turn over. Tried to download a stock file on the second ecm and it went dead just like when I was trying to read original ecm and said communication error. Customer took into gm dealer to have it flashed back to stock and they said they can’t even see the ecm to flash it. Any help would be greatly appreciated.

  2. #2
    Lifetime Member GMC-2002-Dmax's Avatar
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    If the vehicle had any aftermarket radio's, remote starting systems, aftermarket alarms, etc, there i a very good chance the communication was interrupted during the flash process.

    If this was the case the ecm's are either temporarily missing their calibration data, or of you attempted a FULL FLASH then the entire OS and CAL Data is missing.

    You might be able to recover the ecm's by sending them to someone who can repair them, but I would not attempt to flash that vehicle again without using a bench harness and removing the ecm from that vehicle.

    Wait-4-me performance aka Jesse might be able to fix them, look him up here on the forum.

    Good Luck
    www.mscservices.net


    Tuner of many, many Duramax and Cummins Diesels.


  3. #3
    Lifetime Member killerbee's Avatar
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    [QUOTE=Blackdiamond;254707]Tried getting a stock read off an 05 lly and got a communication error. Truck had no communication from ecm what so ever but everything else was reading. Customer had a spare ecm so we plugged it in and truck would turn over. Tried to download a stock file on the second ecm and it went dead just like when I was trying to read original ecm and said communication error. Customer took into gm dealer to have it flashed back to stock and they said they can
    Michael, Systems Engineer 04.5 D-max LLY, Phoenix, Arizona Email
    Custom Tuning Services
    DURAMAX/CUMMINS ECM's TCM's for sale, all years, 20% wholesale discount available
    EFILive's first VGT "Software Wastegate Tune"

  4. #4
    Lifetime Member Chavez91's Avatar
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    The only real time that LLYs die is during the LOCKER patch.... If its a stock full flash or a full flash that isn't locking the ECM to the V2/V3, I've stopped many of full flashes mid flash without bricking. The only time the bootloader gets touched is when the Seed Key is changed during the lockpatch.... only during that specific time is it important to not lose power.....

    If you're doing a read like you say and it locks up, figure out what is talking on the bus and shut it up or bench flash. But in a read scenario is perfectly safe to pull the ECM fuse or batteries to reset the ECM to get it talking again.
    Josh

    '04 GMC LLY
    - L5P, Motech, 6-Spd Conv. ML Trans.
    '05 GMC LLY - 250%, 12mm, 67mm Custom Turbo, 6-Spd Conv. ML Trans
    '19 3500 RAM - Tuned Aisin 0_o

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