Thread: Piggybacked/Dual PCM's?

i just got a basic "it cant be done" he said when someone else figures out how to get into them he can tune them but for now its a no go

thats why you have two completely separate ones that are switched. turn off the car, switch PCM, turn car back on.

in the 08's if its not another acdelco pcm the car wont start at all

but nick that defeats the purpose of tuning, car won't run very well on the non-tuned pcm if he is turbo'd or something along those lines. So you need to leave the ACdelco PCM there so the car runs, then have the Delphi pcm run the engine management. Basically just splitting up the harness. Not sure how the car would react as far as when you start it and it can't detect the engine at all.

Both need to running at the same time. But if you can't get the pinout for the AC Delco you are dead in the water....even for megasquirt.

Only other thing you could do is get a Delphi pcm and full wiring harness and do a swap out, would have to remarry it to the car.

Originally Posted by OmegaRed

in the 08's if its not another acdelco pcm the car wont start at all

See and, that's what I thought Will fixed, using the Delphi PCM's instead...

Guess not?

Originally Posted by FriboRage

There's an issue with the 08's, two pcm's came in 08's... a Delphi one and an AC Delco one. Cars with the Delphi pcm are tunable, cars with the AC Delco pcm are not, and the two pcm's are not interchangable. The AC Delco pcm wont program, last he spoke to me, Will couldnt even read them correctly.

He sent me a Delphi one and it wouldnt even start my car, he confirmed it by putting an AC Delco pcm in his 04 (stock Delphi), and that wouldnt start his car.

The last I spoke to him, he told me he was waiting for a pin-out diagram from a GM tech friend, so he could work on building something to read the pcms, and then HOPEFULLY being able to go on to program them.
That was in like June, though... so Im starting to become curious about any progress (or lack thereof) and I see Omega is too...

'07 and earlier are all Delphi, and fine, though.

.

What would be the reason for running 2 pcm's instead of one

Edit: oop never mind

So 3 options:

1. Dual PCMs; one to run and manage the motor and the other for everything else to make the motor start. UNTESTED and Not 100% since the ACDelco may not let anything run right.

2. Megasquirt; but it sounds like you have to still keep the AC Delco PCM attached some how just to start the car.

3. Full harness/PCM Swap out; Swap for Delphi PCM and Harness. But the BCM may not be happy.

too bad i dont technically own the car yet or i would just swap the whole harness and motor for a 5.3l and be done with it

has someone tried swapping both BCM and PCM from a 05? would that not work?

EDIT i know people have doing the dual PCM thing for a while on LSX swaps in late model cars. Im sure if you dig in LS1 tech you can see how they do it.