Came across this, small arduino project that works well on aldl vehicles, not just for the radio like in the video.
Tx/Rx on the aldl bus.
Coupling this with a MCP2515 Can bus board on an arduino/esp32 should make a useful cheap tool.
https://stuartschmitt.com/e_and_c_bus/
[youtube]https://www.youtube.com/watch?v=OJg6czxvJ2I[/youtube]