[keltis99]

I got 428i and since 2 days the driver side bixenon would not fire, although angle eyes light up fine (in parking lights/DRL mode). i ruled out the D1S bulb problem by swapping the sides. Dash throws adaptive lights and low beam errors. Right unit functions as normal in all modes.

when asked for low/high beams the left side halo rings light up but start blinking and winding noises are coming from inside the unit (seems close to the driver/control modules, but not sure - kind of old printer noise). interestingly when i unplug the left lightbulb in low beam mode the angel eyes are stable (=no blinking). I checked connections, fuses, OBD errors and nothing came up.

anything else i can check before heading to the stealer. a likely (expensive) ballast issue?

thanks for any ideas

Simon
Belgium

[keltis99]

miraculously both xenons fired today...no more errors. i drove the car quite hard with DLR only and after a while tried to switch on the low beams - and voila!
yesterday i tried reconnecting the bulbs, checked the plugs connections once more...maybe it was that fact that the battery got charged more while driving? no idea - will monitor how it goes.