P05 PCMs

[antus]

As I understand it so far, but only from observation, the VPW only is the P05a, the VPW+CAN is the P05b and the CAN only is the P05c. But the P05b and P05c operating systems seem to be interchangable and the PCM talks the protocols in the bin. I am not sure if this is allowed from factory or not. From later PCMs I have learnt that in general GM use the boot loader for the flash process since about the P10, I think (needs verification) and I didn't notice because PCM Hammer was running its own kernel and not using it. This is why some of the PCMs had trouble with re-writing the bootloader, It was never designed for that. So your observation with 12600930 means that service number likely DID come with a p05b operating system, and literally the PCM on my bench is that service number with a c operating system. Latest PCM Hammer build has a check box to allow cross flashing that removes the checks. The intention is to allow a user to force a P05b bin on to a P05c or vice versa. I've confirmed it works. But I was not sure if it was hacky, and if it made sense in the first place or not. But now it looks like someone might genuinely get a P05c from the wreckers and need to force a CAN+VPW operating system on to it if GM did release that hardware with different protocol support across year models.

It is unlikely that someone had cross flashed the different operating system in to yours. I do not think many people are looking at these PCMs, and I can not think of a reason to do it, outside of some conversion where maybe CAN is needed but the junkyard PCM didn't have it. But most people do not even know this function exists in PCM Hammer yet, and it has not been out for very long. It would almost have to be someone from this forum testing it, then scrapping their car, then you pulled that exact PCM in the last couple of months. Which seems incredibly unlikely.

[geep]

that pcm has been on a shelf in my shed for at least 3 years maybe longer

[geep]

.bin out of a 2008 grand prix and the log lots of fffffffffffffff's

[geep]

Here is the .xdf that claude came up with. It has not been tested so use caution if you use it in car.