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Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Mon Feb 21, 2022 5:33 am
by darkman5001
Okay I have managed to get my damaged PCM apart so we can have a look at it's components. I have another P12 that is fully operational that I will use for testing. I am attaching pics of the outside and inside of the P12 PCM as well as a closeup of its CPU and Flash chip. I am not sure who makes the CPU, maybe someone can chime in. I have also found manufacturer documentation for this particular flash chip which is made by AMD. The documentation is very in depth and talks about memory location layout etc. Now that we have pics and info on the hardware, its time to get this badboy to allow PCM Hammer to break through it.
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Mon Feb 21, 2022 5:37 am
by darkman5001
Here are the PCM Pinouts and the flash chip documentation from AMD.
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Mon Feb 21, 2022 10:21 am
by Gampy
Hmmm, I'd have to guess that unit came from the US northeast ...
Thank you for the images!
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Mon Feb 21, 2022 10:44 am
by antus
So it looks like the e38 case, would it be canbus?
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Mon Feb 21, 2022 10:54 am
by darkman5001
There is no CANBUS in the pinouts. Looks like just Class 2 Serial.
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Mon Feb 21, 2022 12:32 pm
by Gampy
Antus, we are getting VPW communication ...
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Wed Feb 23, 2022 6:10 am
by ScarabEpic22
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 platform for 06-07 because the P10 couldn't do CAN comms or use a MAF. It allowed GM to get CAN on the GMT360 for the engine+transmission while leaving the body comms on VPW. GM used the same case and connector style for the LLY Duramax/P12 PCM/E40 ECM.
I'd speculate that using a more "common" PCM that the GMT355/Colbalt SS/others used for the I4/I5s made more sense than continuing with a 1-engine PCM from a $$ standpoint.
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Wed Feb 23, 2022 9:08 am
by darkman5001
ScarabEpic22 wrote:These PCMs do both VPW and CAN. The bench pinouts I have specify both VPW and CAN to be hooked up, I'd have to setup my bench for these and check which comms are used for actual read/write. Seeing Gampy's progress in the other thread, looks like VPW is working.
GM moved to these PCMs on the GMT360 platform for 06-07 because the P10 couldn't do CAN comms or use a MAF. It allowed GM to get CAN on the GMT360 for the engine+transmission while leaving the body comms on VPW. GM used the same case and connector style for the LLY Duramax/P12 PCM/E40 ECM.
I'd speculate that using a more "common" PCM that the GMT355/Colbalt SS/others used for the I4/I5s made more sense than continuing with a 1-engine PCM from a $$ standpoint.
Interesting... I can tell you that I replaced a PCM in a Cadillac XLR and reflashed it myself with TIS2000 and Tech2, and the XLRs PCM looks exactly like this P12 too. Now I'm going to go check and see.
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Wed Feb 23, 2022 9:10 am
by darkman5001
Disregard... The XLR has a slightly different PCM. The part number on the XLR PCM is 12594956, so I don't know which model PCM that falls under.
Re: Delphi P12 PCM (Second Gen PCM for GM 4.2L Inline 6)
Posted: Wed Feb 23, 2022 9:58 am
by ScarabEpic22
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.