Engine Shutdown Performance Timer Code

[LBZ]

Has anyone heard of this one? I loaded a mild 40hp tune into my LBZ and afterwards the CEL came on. When I checked my codes, this was the one that came up and it came back everytime I erased it. I was told by GM that it comes on when the ecm loses power while the key is in the on position. Could this happen when loading a tune? I put the stock tune back in and same problem. How do I fix this issue? Or erase this code? Has anyone else encountered it?

[IdahoRob]

That's a new one to me. If it's doing it with a stock tune, might be a ecm problem.

[LBZ]

Kind of what I thought. Already had to get gm to completely wipe my TCM clean and reload it as it was throwing codes as well. That was only at 2000km

[GMPX]

Not exactly sure what that code is all about, however, most GM controllers (ECM and TCM) write some data into flash memory about recent running conditions etc, if for some reason your ECM is having trouble doing this that might explain why.
Things I would look for, is something shutting off all power too early?, FYI, when you turn the key off all the computers actually stay active for up to 30 seconds before they turn off. If power is being killed during this time (maybe a turbo timer) then it could be interrupting the shutdown process.

Cheers,
Ross

[LBZ]

update--Everytime I flash, I get this code. However, now I can erase it where before I had to unhook the ecm. Once it's gone, it doesn't come back till I flash again. Not a big deal, but I would like to find the source of this problem. I have had no operating or running issues though so plan to just keep givener!!