Wasn't really sure where to post this up.

A while back when I was about to begin my LS swap, I did a lot of digging into DIY flashing a stock computer for cheap for the swap. That LS has since left the garage, but ever since it's been bugging me that the factory 4.3 V6 computer can be flashed to run a 5.3 V8 lol.

So I dug out some stuff and built a thing. Benchtop harness to power up and read/flash the computer.

It's powered by a small 2 amp 12v power supply, has individual switches for 12v constant and 12v ign, and is housed in a random car audio fuse holder because I have like 10 of them kicking around lol.

So far it works with the cheap OBDII bluetooth dongle I have. Can power up and connect to the a computer. Tomorrow my OBDLink LX should be in and I can actually start digging in, downloading the computer, altering some settings, and reflashing!

I have a couple spares to play with

Mainly after little tweaks like turning off the DTC for the down stream O2 sensor, possibly enabling electric fan control, etc.

We'll see!

 

Thats awesome! Following this

 

Interesting - I have to look into that for my 1st gen ECU.
Good idea to look into connecting via the ALDL plug. Im a bit more inclined to place a connector below the dash on the passenger side for the laptop to connect.

Following the progress.

 

This is going to get very interesting

Got one of the computers connected and downloaded today. There's so much fun to be had here lol

Removing the VATs so I can throw the computer into any S10/Blazer if I wanted to, or I could just reassign it my VIN. Calibrating for tire size. Removing the O2 sensor codes.

It's going to be an exciting next few days!

 

Very impressive! Definitely following this!

 

Should prove interesting, if nothing more, just to see the architecture of one without having to fork out hundreds of dollars for something from EFI Live or others.

 

Very interested!!

 

Made a little more progress on this today. At first it was proving to be a little more difficult being that mine is a 2004 model with a bit of a later computer. The two spares that I have were also from 2004, same numbers on the stickers on the outside of the computers. But reading the programming on them I seen that my original had a different operating system programmed to it, an "updated" system. While the 2 spares I have had the older operating system on them despite being the exact same hardware. It confused me at first because there's no "decoder" file for the newer OS, but there is for the older OS, so my variables were not showing right when using the "decoder" for the older OS when trying to read the newer OS. Then found out that I can just flash any of them with the older OS, the the older "decoder" would be able to make since of the data, and I could change any settings that I desire!

Being that I have 2 spare computers, I'm not playing with the programming on the original in my truck, it's going to stay bone stock, that way I have it to fall back on if things go south with this little experiment lol.

I played with and flashed one of them, changed a few things, and threw it in the truck. Happy to report that it seems to be working Have 2 computers now that my Blazer can run with lol.

So now I've played around with and flashed the other spare, changed a couple other little things. Mainly at this point trying to get the tire size calibration right (I overshot on my first flash; use to read low, now it reads high lol). So tomorrow I'm going to throw THAT computer in the truck and see how that goes.


For anyone that's curious and would like to dig into this, I'm using PCMHammer (free) to read and write to the computers, and TunerPro (free) to modify the parameters. With my computers, I'm using the OS 12587603 which is 2004 specific, so with TunerPro you need to use the XDF file (which is basically the "decoder" I was hinting at earlier) for that OS specifically if you have the 12586243 computer.

Along with my bench harness, I've been using a VCX Nano ($100) for USB reading and writing, as it's CONSIDERABLY faster than wireless, but I can also use my OBDLink LX ($50) and do the same thing via bluetooth, it just takes twice as long...

I've tried to do it in the truck, but discovered that you need to fully remove power from the computer to make it reboot for changes to take full effect. You could just disconnect the battery or pull a fuse to do this, but being that this is just a project that I'm working on in spare time, and I have extra computers to play with, I've just been bench flashing them and swapping them out lol.

 

Have you tried, or are you going to try flashing any OS for V8's into the V6 computers?

 

I haven't yet, but I don't see where it would be a problem. Just a matter of changing the cylinder number and engine type in the tuning software.