Where to start?

They go by many names, P01, P59, VPW, '0411 etc . Circa 1999 to 2006. All VPW OBD2 PCMs.
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Where to start?

Postby battlesthecrab » Wed Sep 04, 2019 1:05 pm

Hello, This is my first post. I just spent the last 2 hours reading through the posts here to try and get some info, as well as checked out google and some youtube videos. I have already downloaded PCMHammer and all of the extra files from github. I also have TunerPro RT. I am using a GM MDI, all the drivers are installed and it is up to date. It communicates with PCMHammer no problem, however I have not made my bench harness yet to connect to the 0411 PCM from my LS swapped burb. The PCM in my burb came from PSI Conversions. They flashed it for me and disabled VATS, rear 02s, evap stuff, etc. and it is set up for a manual/non-electronic trans because I was using the stock TH400 from the 89 burb. I have since swapped in a 2004 4L60E, and I have been using some toggle switches to control the shift solenoids in the trans manually. I've finally become fed up with having to shift it manually and want to pull the trigger to flash the PCM and include the 4L60E control. Before I jump in head first and lose my current flash, I wanted to ask what steps I should go about to make a copy of the flash that is currently on my PCM to save in case I want to start over, and also see if someone can point me in the right direction to figure out how to modify the file in TunerPro to flash back onto my PCM. I do have an extra 0411PCM from another engine that I bought that is on a stand currently, So I will begin my trial and error on that PCM as to not brick the one in my functional vehicle. Any guidance would be greatly appreciated. I know I'm asking the most general of questions about this software and I'm sure it has already been discussed many times. I'm just having trouble finding a fairly straightforward "do this to make this happen" walkthrough. As well as attempting to modify my own files, I would be more than happy testing things further as far as the program is concerned using my MDI, if need be. Thanks!

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Re: Where to start?

Postby antus » Wed Sep 04, 2019 1:58 pm

So some basics. The pcm software has an operating system (OS) that runs it, and it also includes the calibration of the car. The calibration must must mach the OS. Also called OSID. So record your OSID from pcmhammer when it connects. This will tell you what definitions you need for tunerpro to edit its calibration (XDF).

Then build a bench harness and try and read it. The tuner might have locked it, and there is information about how to hack around this on the site, but this will tell you what your dealing with.

The PCMs come in 2 main varieties. There is also a rarer early one. The main ones are P01 (512kb) and P59 (1mb). Different operating systems have different capabilities. The P59 also have sligthly different on board configuration depending if they can handle drive by wire. Dont worry about this now but keep it in mind.

Once you have read the first one, do a full write to the second one, then write the paramater block to clone it. Try that one in your car, you should now have a backup pcm.

In tunerpro load the bin, and the xdf, start looking at the tune....
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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Re: Where to start?

Postby battlesthecrab » Wed Sep 04, 2019 4:18 pm

Thank you! I will get a quick and dirty bench harness made up tomorrow to use on my extra PCM and I will get the software installed on my laptop to copy the vehicle PCM. When I read the flash that currently on the PCM I can then save all of that information to my computer, correct? Just want to be sure I'm not going to accidentally lose anything. The spare PCM I have had a 4L60E flash on it, so if I can save the flash from both PCMs before I do anything that would be helpful. At that point I may be able to combine the parameters from the two to get what I need.

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Re: Where to start?

Postby NSFW » Wed Sep 04, 2019 5:01 pm

Yes, the "real full contents" button will copy the entire flash memory from the PCM to your computer. With that file you can make any PCM into a clone of the original PCM.

I don't have any experience with combining pieces of different PCM bin files, but I think that's what the "Bin stacker/splitter" tool in Tuner Pro is for?

Another option might be to copy the most significant tables from the currently-in-the-vehicle PCM into the calibration of the 4L60 PCM - MAF scaling, VE, timing, idle, power enrichment, fuel injectors... heck maybe just copy everything. :)
Please don't PM me with questions about tuning or flashing - start a thread instead. Thanks!

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Re: Where to start?

Postby battlesthecrab » Wed Sep 04, 2019 5:30 pm

NSFW wrote:Yes, the "real full contents" button will copy the entire flash memory from the PCM to your computer. With that file you can make any PCM into a clone of the original PCM.

I don't have any experience with combining pieces of different PCM bin files, but I think that's what the "Bin stacker/splitter" tool in Tuner Pro is for?

Another option might be to copy the most significant tables from the currently-in-the-vehicle PCM into the calibration of the 4L60 PCM - MAF scaling, VE, timing, idle, power enrichment, fuel injectors... heck maybe just copy everything. :)


Awesome, thanks for clarifying. Unfortunately, I haven't gotten my PCM dyno tuned, so while the truck does run, it isn't the ideal tune. It smells rich and plumes black smoke from the exhaust during a WOT shift. So it definitely needs some tuning work to it and I'm hoping the MDI will communicate with TunerPro so I can check real time values and maybe see what I need to change. I have a little bit of experience tuning a '90 Cherokee that had a turbo and a Split Second module on it. I'll keep my fingers crossed and report back what kind of success I have.

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Re: Where to start?

Postby antus » Wed Sep 04, 2019 6:10 pm

Im not sure what logging tools work with J2534 which is the applicable standard the MDI supports. You'll need to do some research there.

I wouldnt worry about loosing the existing auto tune. Forum members can 99% likely provide any factory bin (flash contents, in binary aka raw format) that was released. You'll have all the choice you need when you get to that part. I wouldnt swap segments without a good reason. You'll probably be better off comparing your existing bin to the factory one and recording whats changed. Then load an appropriate auto OS with factory calibration and migrate the same changes in. Then full flash to load the new operating system and calibration to the pcm.

Bin stacker/splitter is more for the older rom chips when the target rom is not the size you need, or you have added hardware hack to switch between two copies of the roms, or are using other similar hardware. Its not really for segment swapping, though if you got serious with the right numbers you could probably do it. Segment swapping compatible segments for the OS is not a beginner topic, and only ever required in special cases.
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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Re: Where to start?

Postby jlvaldez » Thu Sep 12, 2019 6:27 am

This is a helpful thread.

I'm also new to dealing with the binary on these older ECUs. I'm very familiar with HPTuners and have been using that to tune a lot of my vehicles.

The problem I'm having now is that there are some specific binary tweaks I want to make that HPT doesn't give access to.
I was able to pull someone's disassembled binary code and I found the offending line in the binary that I want to change. The problem is I have no idea how to then take this changed hex and then get a valid checksum and flash it to the ECU.

Are there any suggestions on that? I'm familiar with assembly and instruction sets of these processors, but I have never had to try to take a hex binary and attempt to flash it onto a ECU. I've always had my C code and compiled my way from that (for other embedded processors)

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Re: Where to start?

Postby antus » Thu Sep 12, 2019 12:38 pm

Have a look at this viewtopic.php?f=42&t=3845

The OS segment is in 3 chunks, so its a 16 bit sum of those 3 areas you'll need to recalculate and store.
Have you read the FAQ? For lots of information and links to significant threads see here: viewtopic.php?f=7&t=1396

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