Hi Phil
It's a long story, but in summary:
1. Headlight must be cracked, as misting up.
2. Condensation is blowing ballast units (seen corrosion in connector of most recent ballast to blow - cheap ebay unit)
3. Decided to buy New unit from Eurospares (£1500) - Out of stock at factory, and no date for back ordering.
In the meantime, while I wait for the new unit:
4. Decided to see if I have the technical ability to remove the headlight myself (assuming it can be done without having to remove the front bumper!), and see if I can find and fix any cracks.
5. buy another ballast unit from ebay.
I was trying to understand what and how to 'Code' the ballast unit.
sorry to be late to reply. an SD3 is the $50,000 diagnostic system that dealers use to work on the car. many computers on the car need to be configured to work with the rest of the car. I have no first hand knowledge of what needs to be coded for the adaptive headlight feature, other than what I've heard anecdotally.
I do know first hand that replacing a ballast will get the headlight to work (i.e. light up and have low/high beam functionality) without doing anything other than simply plugging it in.
I also know that the ballast also contains the "computer" for the light, but that it is not at all related to any of the auxiliary bulbs like turn signals, running lights, flash to pass lights, DRLs, etc. all of those will work with a completely dead ballast.
so, my suggestion -- while waiting for the $1500 part, buy the $50 part and see if it works.