I think I got an idea how the Headlight Pro (european model) is wired after asking a BMW staff guy at BMW days in Berlin who showed me the wiring plan for my bike (MY2017).
There a 5 wires connecting the Headlight Pro: ground, hight beam, low beam, one for position light and DRL and one for LIN (Local Interconnect Network Bus). The latter probably get's a signal from the bike and tells the Headlight with which intensity the LED Unit shall work: full for DRL or reduced for position light. It also might determine if the DRL is to switch in reduced mode while the low beam takes over (and vice versa) This happens if the board computer is in automatic mode and a sensor at the bike measures how bright it is. For example: If you drive at daylight with DRL and pass a tunnel, the sensor will measure low light, a signal is send to the LIN (I suppose) and this activates the low beam and reduces the LED to the lower position light mode. At least that is what makes sense to me.
Now my question, because I really would LOVE to get rid of my error message ; - )
I replaced the Headlight Pro with a R9T Headlight. The H7 bulb replaces the two H4 bulbs with the same power consumption and makes no problems.
The LED unit in the HL Pro is replaced with a position light which normally draws 5W. In Germany you need to have a working position light. I connected the position light to the DRL wire and put an 39Ὼ resistor to the other wire which feeds the LED unit (which as I know now connects the LIN). The board computer is in non-automatic mode as if I would ride without DRL. Result: everything works fine. At start the position light goes on and after ignition the low beam comes along, no problem switching between low and high beam either. But I got an error message in the display and Navigator 5 tells me the DRL is out of order.
I think the resistor is at the wrong place because it must be at the combined postition light/DRL wire.
But I still can't imagine which draw I must replace with the resistor while running the position light (which others like The Dive Danielle who successfully works with 39Ὼ have not)
The original draws from the LED unit are 8W for the full DRL mode and 1,8W for the reduced position light mode. I could replace the 5W position light with an 1,8W bulb.
If someone has an idea how to eliminate the error message in this setting I would be very happy.
Thank for reading so far by the way ; -)