So moynah; how do you really know that you need a BCM? Did a dealer tell you that? If it's just the alarm that's affected, maybe it's just the alarm? I don't know anything about a BCM just so you know. But if the alarm is truly all that's affected I would fugetaboutit, (as long as the car operates o.k.) and/or get a second opinion. My names Bob by the way. lol