Getting seed/key on locked pcm brute force style

[Montecarlodrag]

Like $150 for the programmer with the adapter plus the hot air station

[JeepsAndGuns]

I am very new to obd2 stuff, so what do yall mean when you say its locked? I have never heard of this before. I have seen several tuning threads in this section but never saw anyone mention unlocking a pcm first.

[mecanicman]

EFILive, HPTuners, and various handheld tuners modify the seed/key as a way of locking the pcm. I am not sure exactly what they do, I think it changes the location the data is stored at. When I try to access it with software I do have it shows finding the original seed but key it generates does not match. I have been able to put together that key algorithm for ls pcms is:

KEY = 934D - SwapHiLo(Seed)
So the formula goes like this
SEED = 0A69
KEY = 934D - SwapHiLo(SEED)
KEY = 934D - SwapHiLo(0A69)
KEY = 934D - 690A
KEY = 2A43
If resulting number is negative, use 1934d.

http://www.miniwebtool.com/hex-calculator/

[Munchies]

it does not modify anything when just reading a ecm out. edit. I reread what you wrote. I see what your saying, just not how I would word it.
The ecm sends a seed, and you must reply with the correct key.

There are 256 seed/key combinations plus a few extra orphans as I understand it. There will be a tool like antus's released soon that will do 411's, and if the dev can find the time, many more GM ecms

[mecanicman]

dimented24x7's tool? Played with black box version.

[JeepsAndGuns]

I have no idea what the seed or key are, or what they even mean in reguards to a pcm. But if I am understanding it right, basicly once you tune a pcm with their software, it mods the code to where nothing else but their software can change or re-tune it?

[lionelhutz]

It's not an inherent locking in the software, it's the tuner who chooses to lock the PCM using the software.