Diagnostic data supported ?

Thanks, helpful reply. "CUMMINS 2003; sc: ECM; 0x10ae" is identical to what I'd like to interface with and there are PIDs in it's list that I'm interested in. The "overlap" you mention means that native GUI doesn't decode description and value for that particular PID ? This ECM would support SBEC3 flashing ?  User's Guide was helpful, thanks.  Also found these videos interesting:  www.youtube.com/@ascension1989

I appreciate you taking time to answer. Although I'm not familiar with ECMs your latest reply and user's guide tells me that high-speed mode requires knowledge of ECM-specific RAM structure while slow-speed mode is a single synchronous call ? I noticed a PID for a cylinder contribution test on these DRBDBReader Cummins records. What's involved in getting a test like this work as I'm interested in trying to figure out something like that ? A query of Internet reveals MPC555 is the microcontroller within CM848.

Helpful walk-through, thank you. Great that this cylinder contribution test should work out of the box. From your example it would seem easy to cobble together code to display any FX in more easily readable ways. The ECM has many "diagnostic" values that I'm interested in seeing, some on a permanent basis. Something graphical ( e.g. line chart, radial gauge ) although I'm still thinking how best to implement. I've seen nice I2C OLED displays. But I think it would be easier to use this scanner as gateway and push desired data to CAN (ESP32 supposedly has such interface) and then display desired data on standard 52mm (2-1/16") CAN gauge.

Part of the appeal of this device is the open-source nature and excellent documentation. I'll likely get one despite no flashing ability. I do see that some scanner/tuners are able to flash the CM848 although they say that cannot read current firmware in flash. They start with a clean file for particular ECM and then change based on tune before flashing. It's hard to weed through all the marketing and vague terms of commercial products for this vehicle.

www.nxp.com/docs/en/application-note/AN2000.pdf

Maybe nobody has tried it with the right tools. ;-)

Thanks for the replies and application note. Beyond my abilities at least without cooperation. But I can do basic interfacing and certainly software so I plan to do some things with this device. Can anybody answer if there are GPIO pins available that can be purposed for CAN controller ? I'd like to make a gateway device to interface with CAN instruments ( so many good ones now ). I understand I still need transceiver for this, but they seem cheap and plentiful.

Sven

That would be great. I'll do some digging for an extra ECM at junkyards, etc. as I don't want to be stranded should something happen and they are getting more difficult to find with every year. If I find and extra I can share or test. Thanks for tip about i2c to CAN module. Didn't know so accessible. With a max i2c speed of 400k my hunch is that such a gateway will be data limited, but certainly useful for a handful of dedicated displays. Looking forward to getting the scanner when back in stock.