Tweet
I'm new to the forum. Saw a post last week about reprogramming the PCM or using a Haltech. The conclusion was that the Haltech wouldn't work.
It seems that, as far as the aftermarket is concerned, the 3.4 is the redhaired stepchild at the GM picnic. Not much out their.
However, there are a bunch of clever, cheap, hardcore, digithead enthusiasts that started designing their own EFI system at:
http://www.diy-efi.org
This same bunch then created another web site and BBS forum dedicated exclusively to GM only based ECUs, PCMs etc at:
http://www.diy-efi.org/gmecm/
From the little bit of research I've done thus far I learned that our PCM is a P66 FLASH programmable PCM. There is another awesome site called TunerCat at:
http://www.tunercat.com
These guys have Software that you can use to copy your PCM's program to your PC, view it, edit it, compare it to other efi programs, save it and send it back up to the PCM.
The real technical obstacle is figuring out what all the code in the PCM actually does. The TunerCat site has a list of all the ECU applications that they have definitively mapped. No suprise, the map for small block V8s were a priority. But they have also mapped 2.8s, 3.1's, 3800s etc Buick Grand Nationals etc. They haven't cracked the 3.4 PCM yet, but they do have alot of utility programs that a technically savy person could use to deconstruct the code and figure out what each part of the code is responsible for.
They talk about P3 & P4 ECUs which require a removable prom, a supply of blank e-proms, a prom burner etc.. but None of that applies to the 3.4 PCM because it is FLASH programmable. As far as Hardware goes, we need two things:
1) An ALDL to RS232 cable and
2) an interface adapter
(3) and, of course a computer ...
You can find a list of suppliers for these bits on the TunerCat site under the links section. You could also make your own bits if you search the diy-efi site for instructions. The diy site (& the GM-ecm part) also has a lot of good background info on how to program ECUs and how the program file is arranged.
Anyway here is a link to a site to get the OBD1 style ALDL to RS232 cable and the interface:
http://www.ttspowersystems.com/
Seems that since many here share the same interest, that we could crack this thing.
Could you imagine re-writing the stock PCM to handle fueling, timing etc for boosted applications? Hmmmmmmm......
Regards,
Brian Corrigan
It seems that, as far as the aftermarket is concerned, the 3.4 is the redhaired stepchild at the GM picnic. Not much out their.
However, there are a bunch of clever, cheap, hardcore, digithead enthusiasts that started designing their own EFI system at:
http://www.diy-efi.org
This same bunch then created another web site and BBS forum dedicated exclusively to GM only based ECUs, PCMs etc at:
http://www.diy-efi.org/gmecm/
From the little bit of research I've done thus far I learned that our PCM is a P66 FLASH programmable PCM. There is another awesome site called TunerCat at:
http://www.tunercat.com
These guys have Software that you can use to copy your PCM's program to your PC, view it, edit it, compare it to other efi programs, save it and send it back up to the PCM.
The real technical obstacle is figuring out what all the code in the PCM actually does. The TunerCat site has a list of all the ECU applications that they have definitively mapped. No suprise, the map for small block V8s were a priority. But they have also mapped 2.8s, 3.1's, 3800s etc Buick Grand Nationals etc. They haven't cracked the 3.4 PCM yet, but they do have alot of utility programs that a technically savy person could use to deconstruct the code and figure out what each part of the code is responsible for.
They talk about P3 & P4 ECUs which require a removable prom, a supply of blank e-proms, a prom burner etc.. but None of that applies to the 3.4 PCM because it is FLASH programmable. As far as Hardware goes, we need two things:
1) An ALDL to RS232 cable and
2) an interface adapter
(3) and, of course a computer ...
You can find a list of suppliers for these bits on the TunerCat site under the links section. You could also make your own bits if you search the diy-efi site for instructions. The diy site (& the GM-ecm part) also has a lot of good background info on how to program ECUs and how the program file is arranged.
Anyway here is a link to a site to get the OBD1 style ALDL to RS232 cable and the interface:
http://www.ttspowersystems.com/
Seems that since many here share the same interest, that we could crack this thing.
Could you imagine re-writing the stock PCM to handle fueling, timing etc for boosted applications? Hmmmmmmm......
Regards,
Brian Corrigan
Comment