The CAN capture that lied
The OVMS module talks to the car over two buses. CAN2 handles powertrain — BMS, gear selector, VIN. CAN3 handles the body network — speed, GPS, clima, locks. The J533 gateway sits between them and bridges selected frames. Not all traffic. Specific IDs it’s programmed to forward. Early captures used a script with a bus-labeling bug. Powertrain frames from CAN2 were written to the capture file with bus tag 3 — the body network tag. In the logs, frames like 0x131 (SoC), 0x187 (gear selector), and 0x191 (BMS current) appeared to be arriving on CAN3. ...