GM Gen III, IV, V and V+ CAN data mapping

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gixxer92
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GM Gen III, IV, V and V+ CAN data mapping

Post by gixxer92 »

I’m capturing raw GM CAN traffic with a Macchina M2 and mapping it to usable ECM and TCM logging channels. My current focus is E92 and E38 ECMs and their transmission interfaces.
In my current setup, I’m recording about 2,800 frames per second to SD without observed loss. That’s an observed rate, not a confirmed limit of the M2 or card.

Does anyone know of public maps, DBCs, documentation, or previous threads identifying message IDs, sending modules, signal positions, scaling, units, and validity bits? I’m also interested in methods for matching broadcasts and diagnostic responses to known scanner channels.

I’ve looked through the Giuthub, commaai and a few other public sources, but I’m looking for additional controller-specific mappings or validation methods.
kur4o
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Re: GM Gen III, IV, V and V+ CAN data mapping

Post by kur4o »

If you have bin files out of pcm and tcm you can easily find what is being sent and received through bin analysis, there is some RX and TX tables, you can even trace each message format to specific ram and figure what it is.

Broadcast data vs data logging format is vastly different, most data logging uses active communication and request specific PIDs or Ram addresses.

broadcast data is for passive logging and is limited to what is configured in module, with fixed rates and data.
fl0wl0w
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Re: GM Gen III, IV, V and V+ CAN data mapping

Post by fl0wl0w »

GMW8762
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gixxer92
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Re: GM Gen III, IV, V and V+ CAN data mapping

Post by gixxer92 »

fl0wl0w wrote: Sat Oct 10, 2026 6:30 pmGMW8762
Thanks, that’s the path I’m working down now. I’ve also got the 2018 revisions of GMW3110 and the GMW8772. They’ve really helped make sense of what I’m seeing in the BINs, especially how the transmitted CAN data ties back to the variables used in the algorithms and calculations.
Pretty cool to see the amount of data coming on to the SD card that you can't funnel through a USB cable.