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LT1 OBD2 Seed / Key algorithm
Hello everyone!
I'm writing a program to reflash OBD2 LT1 PCMs and I'm having trouble reverse engineering OBD2 LT1 PCM seed/key algorithm. OBD1 is simple, key is just one's complement od the seed.
OBD2 is harder, for now I have two known good seed / key pairs:
Code:
seed: key:
0x3192 0x5B3F
0x3BBA 0x58B5
There is a document covering GM's 256 key algos, I've made a program calculating all 256 of them, but there seems to be no algo that has a result matching the above...
So, either I made mistake converting the data from STGTERM.DAT (I doubt that, I've made a script to change the binary to a code, and the algo for LS1 PCMs works correctly), the author of GM seedkey.doc document made a mistake, or the 96-96 LT1s use different algorithm, not in the 256 list.
If any of you have known good seed / key pairs from LT1 OBD2, please share, it will help hacking the algo :)