What's the a3ad BMW code?

The A3AD (41901) code on a BMW is listed as CAN-Message from steering engine, missing message: Engine data. You're unlikely to see this code alone, as it's indicative of a communication fault from the ECU. Typically with this code, You'll have the "infamous dashboard C-HRistmas tree", where most of Your icons are lit up and Your gauges are going bonkers. As You can probably surmise, this is an electrical issue. You've either got an alternator that's putting out too much juice, or a fuse that's blown, but didn't protect the console. This can also occur when the ECU itself has failed or started to fail. The best course here is to bring Your beemer into the dealership to have it professionally looked at.