Yes, I did finally get this totally sorted a few months ago. I ended up driving around with an assortment of different ballasts for a while, and endured the Headlight System Fault at every start. The mismatched ballasts also created some other nagging issues across that CANBUS circuit, all of which I’m thrilled to report are now long gone. I now have 2 OEM ballasts ending in “03”, both coded with PIWIS.

Ballast part numbers must match. I also was never able to properly program an aftermarket ballast with an OEM ballast in the other light. I always got the Headlight Fault warning through both scenarios.

I scoured eBay for a few months and found my ballasts for a solid price. Hope this helps

 

PIWIS2+ only, yes. Though I was able to code 2 knockoff chinese ballasts in my car and they work fine. Matching pair. I have programmed "02" revision OEM used ballast to my "02" original OEM ballast as well. I have not tried to program an OEM ballast to a knockoff ballast - would be an interesting experiment I suppose. I have several sets of ballasts sitting on a shelf at this point, lol.

 

@slavie and @PourBoi-Jay , would you guys mind helping a fresh Porsche newbie with a 2018 Cayenne (that I just bought 2 weeks ago) with the same issue? I replaced my ballast on the previously nonfiring headlight and now I at least have headlights/ DRLs working but no adjustment (as well as the dash adjuster function error) and no high beams. I'm in Westchester, NY so not too far if you guys can help a noob out. Lunch and brews on me.