http://e36-drift.blogspot.no/2009/04/14-diy-service-indicator-reset.html
*** SPECIAL NOTE REGARDING SRS SYSTEMS ON ***
E24 AND E30 CHASSIS
(For use with Baum Tools CS1000, Carsoft Software or BMW MODIC.)
On some E24 and E30 model BMWs, the RxD and TxD lines from the SRS control unit are not integrated into the 20 pin
diagnostic socket found under the hood. In order to diagnose and reset SRS lights on these vehicles, you must tap
directly into the harness coming from the SRS control unit.
SRS
bmw code defaut.pdf