What was done
A Claude Code skill correlates raw CAN frames with a reference signal and fits bit positions, scale and offset. It decoded speed and RPM on a Mercedes E350 in under five minutes, plus signals on a Hyundai and an Opel.
Where the human stepped in
One decode showed -1.6 km/h while parked and had to be anchored to zero; invalid values had to be masked; several OBD2 PIDs were never found. The method needs a reference signal a human can capture.