Seed/Key algo

I'm hoping somebody here might be able to help with this.

Is there any software that can find the combo between a seed and key?

General Motors uses a seed/key to unlock the their engine controllers to allow for programming. While I have been able to hack the code, nobody is able to figure out what the seed/key
combo is.

The seed and key is stored in the ECM.
It is not calculated by the ECM, only the returned key is checked for a match. The scan tool (TechII) made for GM does the calculation when it gets the seed from the ECM (engine controller).

I have been able to get several seed/key combos by removing and reading the flash chip contents.

How do I tackle this this?

Thanks.

[Squidge]

If your lucky, you may be able to find a firmware upgrade for the tech tool and decompile that. There's plenty of upgrades available, so one of which is bound to have been released at some time or other.

I do have a dump from the flash card of from a TechII.

I tried to disassemble it, but it's not comming out right.
I know where the PCM (powertrain control module) program is on there and stayed away
from that (68K processor)

It appears to be intel code, but I think the main program is
in the TechII and the flash card is full of indexed sub routines.
Some of them look ok, others end with errors.

That is going to be impossible to find.

I have another program by an aftermarket company, but it's packed/compiled. I tried using compiler detection 2000, but it can't figure out what compiled it. They also ecnrypt their PCM
images.

I know the seed/key is based on the vehicles VIN number.
I was hoping there would be a program that might be able to narrow down some combos if I gave it enough info.

The problem with this is where do you start

Thanks.