Success reading I-CAN bus on Ford vehicle but not MS-CAN

[cr08]

Hoping someone can help figure out the issue here. I've done a TON of troubleshooting so far on this and here's kind of a summary of what I'm working with:

Running an ESP32 Devkit1C_V4 board with the ESP32-WROOM-32D chip. SN65HVD230 CAN transceiver tied into GPIO 4 and 5.

Previously ran this setup with great success doing some CAN sniffing on the I-CAN bus (500k) on my Ford vehicle through Savvycan. It's set up in AP mode and having Savvycan connect in network mode.

However now I am wanting to shift gears to another bus. In this case MS-CAN (125k). Connected through the OBD port and pinouts verified. No gateway/security mess on my vehicle and confirmed via wiring diagrams. Savvycan continues to show the de ad heartbeat messages going back and forth but nothing else comes through.

On a whim I tried a barebones sketch that just sets up the TWAI infrastructure and prints received frames to the serial monitor. There I am getting valid data. Just not in Savvycan/via ESP32RET. But just for MS-CAN (so far. I have two additional buses, HS and HEV. I-CAN is the only one I've confirmed works reliably so far).

Thoughts?

[JoeBargo]

What vehicle is it? or if you have the network diagram that would help. I'm not familiar with ford using "I-CAN" designation for any of their protocols...

[cr08]

It's a 2013 C-Max (North American Hybrid/Plugin). I-CAN has been around in Ford's fleet but mostly older models. It's primarily for infotainment related modules. I don't know the exact cutoff but I think in some vehicle models they began migrating those modules onto secondary HS1/2/3/etc CAN buses in the later 2010's.