Seed/Key, what is the purpose?

[GMPX]

Well, pulling ECM's apart for tuning is common place on some European makes, hopefully GM will never make us have to resort to that, lets keep the seed/key system they have now running for a bit longer please!
http://wiki.obdtuning.com/index.php?...DM-Instruktion

Cheers,
Ross

[CalEditor]

Ross do you have access to TIS and a Tech II or a MDI?

[GMPX]

Yes, TIS2WEB (ACDelco TDS) plus a Mongoose and TechII.

[Garry]

Well, pulling ECM's apart for tuning is common place on some European makes

... which often is due to the fact that the tuning information is stored on (E)PROMs, which can only be changed by removing ... GM's solution is much nicer ...

[GMPX]

Not so I'm afraid, the reason is that by pulling the ECM apart like shown in those photo's means you do not have to worry about figuring out the reflash process, some of those European cars have encryption on the comms which would make reflashing via the OBD-II Port very hard (if not impossible).
On those ECM's shown they are all PowerPC based, given that, with the BDM port on the PowerPC you can dump the entire contents of the flash (internal or external) without worrying about any OBD-II comms.

Cheers,
Ross

[CalEditor]

Yes, TIS2WEB (ACDelco TDS) plus a Mongoose and TechII.

Great Ross

I will send you an email on a process I use to flash custom tune with TIS.
Maybe you already know how.

[GMPX]

Thanks but I really have no need, these days I rarely ever do actual tuning!
I have a feeling I know what you do though as all files that get flashed are cached on the PC

Cheers,
Ross

[CalEditor]

I got the idea about 2 years ago after reading about SPAT zip files.

Then I had some issues and dropped it.

I got talking with some friends and it just clicked.

[CalEditor]

I had a Seed of $5F0D and I did "something" and now it is $0000. Is this now Security locked or is it open?

I will try to get more info on what I did.

[MICK]

You could disable the Seed/Key by setting the PCM Vulnerability flag.

That will shut down the seed/ key side of things.

There are two sides to locking a pcm, those who do and those who don't.

Funny, as recently a tuning shop asked me if i could disable pcm locking on LS1's......good result.....

Mick