https://draft.caps.is/tags/debugging/Recent content in Debugging on DraftHugoen-usSun, 10 May 2026 00:00:00 +0200https://draft.caps.is/posts/can-capture-that-lied/Sun, 10 May 2026 00:00:00 +0200https://draft.caps.is/posts/can-capture-that-lied/<p>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&rsquo;s programmed to forward.</p> <p>Early captures used a script with a bus-labeling bug. Powertrain frames from CAN2 were written to the capture file with bus tag <code>3</code> — the body network tag. In the logs, frames like <code>0x131</code> (SoC), <code>0x187</code> (gear selector), and <code>0x191</code> (BMS current) appeared to be arriving on CAN3.</p>