What changes
Central electrics 09 long coding, byte 10, bit 0 = 0 (light scenario). Opening any door switches on all interior lights, not only those on that door's side.
Details
From the factory the bit is set: only the lights on the side of the open door come on. To restore the factory behaviour, set the same bit to 1. A long coding parameter of the MLB Evo central electrics unit (J519). One bit changes, the other bytes stay. 09 coding on MLB Evo usually needs no access code; from model year 2019 the unit may accept changes only with the bonnet open. If the unit is SFD-protected, a3c warns before writing.