What changes
Central electrics 09 long coding, byte 2, bit 2 = 1 (drl_break). While the parking brake is applied, the daytime running lights are off.
Details
Handy when parked with the engine running: the DRLs do not dazzle people in front. Release the brake and the lights come on. To turn off, set the same bit to 0. 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.