GM-LAN bible but for J1850 VPW

They go by many names, P01, P59, VPW, '0411 etc. Also covering E38 and newer here.
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Fixed until broken
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GM-LAN bible but for J1850 VPW

Post by Fixed until broken »

Is there a document like the https://docs.google.com/spreadsheets/d/ ... sp=sharing GM LAN Bible for Class 2 stuff?

To give context. I really just want to be able to tell a GMT-800 cluster Transmission temp numbers to test the feature when modding them. I used to use a PCM in a box with some pots on it to do this. Once someone else figured out how to send the message to the cluster to sweep all the gauges like a tech 2 does I sold my PCM in a box because I thought I didn't need it anymore. I didn't realize that the diagnostic sweep message will sweep the transmission temp gauge even if the cluster isn't programmed to use the gauge

For anyone who wants to know how to do that it's covered in this post viewtopic.php?f=13&t=7040 People who have been having issues with doing what's shown in the post, it's just faulty or poorly designed Elm327s. we covered that on my Facebook group.
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Tazzi
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Re: GM-LAN bible but for J1850 VPW

Post by Tazzi »

Unfortunately does not exist as GM never made it consistent between vehicles.

For the small contract work I have had in the past for testing clusters and radios on older vehicles, every single car has its own 'broadcast' ID's and data that was used to wake up modules, put to sleep, live data display ect.

It wasnt until Global A (2013ish onwards) where everything became consistent. :thumbup:
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Re: GM-LAN bible but for J1850 VPW

Post by NSFW »

This seems like something the community could create, little by little. Start by recording the messages sent by a Tech 2 for various tasks, and the replies that it gets.

Of course that would require a Tech 2 and an app that monitors the bus, at the very least. Better yet, an app that monitors the bus and tags each message with whatever information we know about it, so that unknown message stand out in the recording. I think jvaldez was working on something like that.
Please don't PM me with technical questions - start a thread instead, and send me a link to it. That way I can answer in public, and help other people who have the same question. Thanks!
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Re: GM-LAN bible but for J1850 VPW

Post by gmtech825 »

I could help out with the tech2 monitoring I believe. It would help if I had a better way to monitor the buss. Has anyone been able to get the drewtech bus monitor to work? I've sent messages with it but for some reason it never picks up any traffic.
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Re: GM-LAN bible but for J1850 VPW

Post by Tazzi »

gmtech825 wrote:I could help out with the tech2 monitoring I believe. It would help if I had a better way to monitor the buss. Has anyone been able to get the drewtech bus monitor to work? I've sent messages with it but for some reason it never picks up any traffic.
What settings do you have for the drewtech bus monitor? Might need to set the mask to 000000 so that it allows all frames to pass through. :thumbup:
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gmtech825
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Re: GM-LAN bible but for J1850 VPW

Post by gmtech825 »

Under the filters tab there's a pass all filter that can be selected. I tried that but still couldn't get it working. I do have a pico scope I've used for can traffic, but that seems to miss some messages. I can check and see if vpw is supported by the pico serial decoder.
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Re: GM-LAN bible but for J1850 VPW

Post by ironduke »

I wrote a very rough logging program that does vpw, 6&14, and pin 1.. It does have filters you can use but it can also log everything.. Either to the screen or to a file.. I posted it up here somewhere, I'll try and find it and see if it's the latest version I've been playing with..

It's not fancy, it doesn't identify messages or anything, you get to do the hard work, lol..

as far as I know it does work with just about any J2534 device, I can only test with the GM mdi though..
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Re: GM-LAN bible but for J1850 VPW

Post by ironduke »

Something else I had found a little while ago.. link is below.. It is not my work and I don't know anything about it past what google finds, There is a .msi download that works ok to install it and it does work but I have been unable to download the source and get it to compile to something workable.. You install it and it installed itseld and adds some registry entries to appear to be another J2534 device.. When your connecting to a device you would pick the logger device and it opens another dialog window where you then select the device your actually using.. It logs a lot of info and seems to catch everything. It throws the logs in the documents folder, when I change the folder it doesn't seem to save anything though so I have to keep it pointing to the my documents folder.

https://code.google.com/archive/p/j2534 ... /downloads
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Re: GM-LAN bible but for J1850 VPW

Post by gmtech825 »

ironduke wrote:I wrote a very rough logging program that does vpw, 6&14, and pin 1.. It does have filters you can use but it can also log everything.. Either to the screen or to a file.. I posted it up here somewhere, I'll try and find it and see if it's the latest version I've been playing with..

It's not fancy, it doesn't identify messages or anything, you get to do the hard work, lol..

as far as I know it does work with just about any J2534 device, I can only test with the GM mdi though..
that seems like it would be perfect, and I believe I found it: viewtopic.php?t=6773&p=106591

I'll give it a try. OP let me know if there's something specific I can log from the Tech 2. (gauge sweep test maybe?)
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Re: GM-LAN bible but for J1850 VPW

Post by Fixed until broken »

Tazzi wrote:Unfortunately does not exist as GM never made it consistent between vehicles.
Makes sense I didn't know for sure but thought this might be the case.

I was hoping it might be the same across the board for a lot of the basic stuff just because a GMT-800 pcm can control a trailblazer cluster. So I would say its safe to guess some of it is at least cross-platform for a few vehicles. I may justhave to build a new pcm in a box and start sniffing it.
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