B3A31: Active Aerodynamic Feature Control Module D Power Mode Circuit Low Voltage — what it means, the affected system and what to check before replacing parts.
Active Aerodynamic Feature Control Module D Power Mode Circuit Low Voltage. Source catalogue definition; confirm applicability using vehicle service information.
Affected system: Body
Also written as: B3A31-00, B3A3100 (some scan tools add the fault-type byte, e.g. -00).