No, the BCM has nothing to do with bags. The Bag Brain controls everything in the SRS system directly, and the only other controllers it talks to are the cluster and sometimes the ABS. The '05's all had passenger bags, just not all of them classified the passenger. OCS's main job is to detect a baby or juvenile in the seat and suppress the bag (or set it off at low power on later models) depending on the passenger's weight. Without OCS, the bag will just blow unconditionally.