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Thread: VCM Suite, IDA Pro, and patching

  1. #1
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    VCM Suite, IDA Pro, and patching

    I want to be able to disassemble the firmware, and eventually patch it and reflash the PCM with my changes. Is that possible with VCM Suite?

    I ask because I've had a lot of fun doing this with my Subaru and I'm looking for tools to do it with a 2002 C5 Z06 now.

    Thanks!

  2. #2
    Tuning Addict 5FDP's Avatar
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    What do you mean by disassemble the firmware?

    Never heard anyone ask that before.

    HPT allows you to change hundreds or thousands of parameters within the calibration depending on what you are after. Like timing, airflow calculations, fueling, torque mngt and a gajillion other things.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Advanced Tuner jsllc's Avatar
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    I believe you are asking if HPT will pull the code from an ECM so that the raw bin file can be run through a disassembler. If so the answer is yes and no. The file pulled is the machine language combined with other info from HPT and then encrypted. All you have to do is figure out the encryption and file format. Do not know of anyone that has. Great summer project for those looking for something to do. LOL!

  4. #4
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    Quote Originally Posted by jsllc View Post
    All you have to do is figure out the encryption and file format.
    Ha, "decryption" could well be far harder than building read/write tools from scratch. Not even gonna go there, unless it's something trivial, like raw firmware with a header/footer or simple container around it.

    I got a raw dump from an ECU like mine from someone over at LS1Tech, and have (just barely) started disassembling it. But there's not much point continuing with that until I have a way to read and write the PCM.

  5. #5
    HP Tuners Owner Keith@HPTuners's Avatar
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    We have a user defined parameters feature that you can use to modify parameters you've mapped out with Tuner Pro.

    It's not supported on every controller, and on controllers that it is supported on, there are address restrictions.
    We got this guy Not Sure, ...

  6. #6
    Senior Tuner DSteck's Avatar
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    Quote Originally Posted by Keith@HPTuners View Post
    We have a user defined parameters feature that you can use to modify parameters you've mapped out with Tuner Pro.

    It's not supported on every controller, and on controllers that it is supported on, there are address restrictions.
    Are the address restrictions intended to stop people from editing dead space, stop people from editing the operating system itself, or something else? I haven't found anything I want to add that is in a restricted address, but I'm just curious.

    Kudos for adding support to edit T42s and FPCMs.

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  7. #7
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    Quote Originally Posted by 5FDP View Post
    What do you mean by disassemble the firmware?

    Never heard anyone ask that before.

    HPT allows you to change hundreds or thousands of parameters within the calibration depending on what you are after. Like timing, airflow calculations, fueling, torque mngt and a gajillion other things.
    Those things are all changes to the data in the PCM. I'm looking for tools that I can use to make changes to the code in the PCM.

    For example, my Subaru will now match the RPM to the gear when I'm downshifting. Editing the data in the ECU won't make that possible, it requires adding a bunch of new instructions to the code. And it works well, so I want to do the same thing in my Corvette.

    https://github.com/LegacyNsfw/EcuHacks

    (I've heard there is an aftermarket "throttle blip" device that one can add, but unless it knows the wheel speed and engine RPM I suspect that it isn't truly doing rev matching, it's just simulating an identical poke of the gas pedal everything you downshift, regardless of engine RPM, wheel speed, or gear.)
    Last edited by NSFW; 01-28-2018 at 12:36 PM.

  8. #8
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    Quote Originally Posted by Keith@HPTuners View Post
    We have a user defined parameters feature that you can use to modify parameters you've mapped out with Tuner Pro.

    It's not supported on every controller, and on controllers that it is supported on, there are address restrictions.
    Can HP Tuners export the raw firmware so that Tuner Pro can open it?

    Can the "user defined parameters" feature be used to patch instructions in the code? I'd be looking to replace one long sequence of bytes with another.

    Is it supported on the controller for a 2002 C5 Z06?

    Thanks!

  9. #9
    Tuner in Training
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    Yeah can hptuners mpvi2 pro set and features with pro link. For a 2002 trailblazer ls 4.2 l6 with p10 i dont have any real operating system from wat my unit is showing me

  10. #10
    Tuner in Training
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    I just found out about tunerpro and thatts only cause i wanted to compare it to the elm 327 i got for cheap