An OBD II reader is not going to give you any information other than a code set by the electronic engine emissions system. It is limited in scope and solely based on the federal OBD II mandate for not polluting the air...thus emissions is what its based on.
To speak/communicate with the BMW proprietary control modules etc...you need BMW DIS/GT-1/MoDic...or after market software/hardware like INPA/CarSoft/PaSoft/etc.
You brought up "trifecta" so that means you're somewhat familiar with the search terms. Bluebee has some extensive threads on the trifecta/bifecta warning lights. You can easily find these threads by googling "BMW trifecta Bluebee".
Also, the rear speed sensor is what sends the distance/speed data to the ABS/ASC/DSC control module, which then sends that data to the IKE & DME...so if your speedometer/tachometer isn't registering...you should consider checking that area, too.
Good luck.
