To program keys of old BMW with N46 engine, ISN is required. If all keys are lost, we can’t get ISN via OBD on part of cars, so we may read it on bench.
1.Connect pins on OBD port of device and on engine ECU
2.GND and +12V mean extra power supply
3.Add a 120ohm resistor between CAN-H and CAN-L
We can also use Godiag Full-Protocol Cable. With short-circuit button on GND 4-5, process will be easier.