So if I read that correctly then the P12 was used on 4,5, and 6 cylinder engines. Which would be really interesting they all used a common Operating System with different calibrations like the P01/P59 did. Yes, all Atlas family engines (I4/I5/I6, 2.8/2.9/3.5/3.7/4.2L displacements) used the P12 at ...

Maybe this is the main or secondary/DBW one? I believe there are 2 chips that are really CPUs in the P12 (and P10). The main and secondary, with secondary being the DBW/electronic throttle controller. Both are in the PCM, similar to how all Gen IV+ ECMs do DBW.

I have an opportunity to get some PCMs from my local salvage yard. Does anyone KNOW what years the P10 vs P12 usage was? There are 2002, 2003 and 2007 Trailblazers. Doesn't list any other vehicles with the 4.2l, nor any of the cars. Mike 2002 and 2003 use the P10, and 2007 uses the P12. Here's a br...

Pretty sure E67 is CAN not VPW, whole nether ball game! Hmm ok, I looked at some E67 pinout diagrams a bit more: E67 has 2 pins (+/-) assigned to High Speed GMLAN Serial Data Bus and a separate pin for Class 2 Serial. I believe HS GMLAN = CAN, is Class 2 Serial considered VPW? If not, then I'm mixi...

I'm not as familiar with some of the early Northstar stuff

I looked at that part number, should be an E67 ECM. I looked at the 08 XLR-V file I have, can confirm it's that's an E67.

These PCMs do both VPW and CAN. The bench pinouts I have specify both VPW and CAN to be hooked up, I'd have to setup my bench for these and check which comms are used for actual read/write. Seeing Gampy's progress in the other thread, looks like VPW is working. GM moved to these PCMs on the GMT360 p...

Happy to help any way I can, been tuning these for 17 years now! They're getting more popular in swaps now too, so being able to use something open source would be great.

E40 was V8 (maybe a random V6 too?) only, P12 was used on inline engines only and does transmission control as well (last PCM from GM). From what I've read, they're in the same case, but have different hardware internally. The E60/LLY Duramax ECM uses the same case and harness connectors as E40+P12...

None of the ones I have are E40's.. I didn't know I have 3 E78's, lol.. Below is what I have that isn't an E40 or E78 but does have the blue,black, and gray connectors. 15246452 12604995 E40, E67, E78, P12, E60, and a few others all have 3 connectors of varying sizes -gray, blue, and black. 1260499...

E40 was V8 (maybe a random V6 too?) only, P12 was used on inline engines only and does transmission control as well (last PCM from GM). From what I've read, they're in the same case, but have different hardware internally. The E60/LLY Duramax ECM uses the same case and harness connectors as E40+P12,...