What changes
Unit 09, object 0A58: byte 4, bit 2 = 1. With the light switch at “0” the daytime running lights are off; in AUTO they work as usual.
Details
Setting of the newer MQB body control module. Check your local rules: in many countries daytime running lights or dipped beam are mandatory while driving, and with this setting the car drives without lights at “0”. On the older module the same option is object 0D02, byte 1, bit 2, so a3c refuses there before writing. Unit 09 on MQB Evo is SFD-protected — a token for unit 09 is needed. Roll back by writing the object backup from history.