see if there is a plug for the seat control module. I would research the wiring and chase the failure point further. You could also ask BMW about it. Maybe they have some insight as they deal with thousands of maintenanbce issues.
Audio: Jehnert Flatline speakers, Mobridge M1000 DA2 prepro, Helix P-DSP, Zapco Z-150.6 amp, CIC iDrive upgrade
Performance: Cobb Pro Tune, AR Downpipes, ER FMIC/CP, DCI, RB turbos, KW V2 coilovers, Fuel-It Stage 2 pump w Ported fuel rail, Mfactory LSD