Entering the PCM World

Bosch Motronic etc ECUs and PCMs
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GeicoGecko
Posts: 4
Joined: Sun Aug 02, 2020 8:22 pm
cars: LS2 Miata, LS3 RX8, L96 2500HD

Entering the PCM World

Post by GeicoGecko »

Over the past week I have done a lot of reading on various forums, after discovering a thread on an LS site where a group (looks like Pete is included) is working on making the LS1 ECUs (P01 and P59) opensource. I think this is a fantastic idea and would love to contribute.

After realizing that the ECUs I have lying around weren't compatible with that effort, I found my way to this forum and found Tazzi's thread on the E38 kernel development.

A few years ago I became obsessed with the LS engine and it has subtly found its way into my life in almost all of my vehicles. The truck has an L96 and I believe an E78 ECU, the daily (RX-8) has a standalone PCM for an LS3 (not sure of the variant but will check when I can) and the race car (Miata) has an LS2 with an E40. I understand the E40 is a bit of a awkward variant so I will ignore that for now. I also have a spare E38 with a full loom from a previous project.

I have a background in embedded programming and would love to participate in anyway I can (I also do some C# coding from time to time). This morning I managed to get my E38 bench set up and running. I have tested the CAN communications with a couple of OBDLink devices I use. Based on my reading it looked like the VCX Nano would be more appropriate so I ordered one of those on Sunday (hopefully it will be here soon). I probably should have checked here first but hopefully that is the correct one?

In the past I have used HPTuners to tune all of my engines but have become frustrated by the move to the MPVI2. I still have my V1s and have no current plans to upgrade. The goal would be to be able to tune without it if possible (with perhaps the exception of the E40).

I would like to look into reading the binaries and disassembling them to understand what is happening. From what I read it looks like IDA is the most popular but I do not currently have a license. Has anyone had success using radare2 for this? I looked at their site and I can see some support for the processors used in the E38.

Look forward to learning more!
Last edited by GeicoGecko on Sun Aug 16, 2020 11:02 am, edited 1 time in total.
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Gampy
Posts: 2331
Joined: Sat Dec 15, 2018 7:38 am

Re: Entering the PCM World

Post by Gampy »

Hi GeicoGecko,

Many are now using Ghidra for reverse engineering.

-Enjoy
Intelligence is in the details!

It is easier not to learn bad habits, then it is to break them!

If I was here to win a popularity contest, their would be no point, so I wouldn't be here!
User avatar
GeicoGecko
Posts: 4
Joined: Sun Aug 02, 2020 8:22 pm
cars: LS2 Miata, LS3 RX8, L96 2500HD

Re: Entering the PCM World

Post by GeicoGecko »

Thanks Gampy! I wil be sure to check it out :)

So I am making progress if but a little slow. I received my VCX Nano and spent ages trying to get the software installed. At first I thought it was issues with Windows 10 (there are plenty of those!) so tried it on an old Win 7 boot camp partition. I discovered there that the Manager software on the DVD was corrupt.

I then retried the tech2win and GDS software but still no joy. Next I tried running the individual installation components (rather than the auto install). Now I could see that other executables on the DVD were corrupt which basically meant the DVD was rubbish.

An email to support later and they gave me links for the software. So far I have GDS2 up and running and communicating with the E38.

I have also made some progress with my OBDII logger. I know there are plenty out there but I wanted to get back into the CAN frames and find a more intuitive way to display the frames for reverse engineering. Currently using an old Syswoxx USB/CAN device I had lying around.

I know eventually I will have to start digging into the Mazda ECU to get seamless integration with the E38 PCM. So question for others, what does the VXDiag do that the VX Nano doesn’t?
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