I have a 2001 Saturn L200. For the last week or so the vehicle has had a mind of its own. Whether the ignition is on or off the doors will unlock on me. Other times the trunk will pop open and a lot of those times the doors unlock, the trunk pops open and the horn will honk simultaneously. I have noticed to that the secuirty light will flash when all 3 things happen at the same time. Also, everyonce in a while the windshield wipers will activate for one wipe then stop, I have not used the key fobs in a few months. I believe the possible problems is a fault in the secuirty system or BCM failure. Please help.
Taking the batteries out of all remotes and seeing if the problem continues is one thought, is there one stuck in your car seat? It is possible there is one fuse you can pull to disable all that stuff without adversely affecting regular operations.
I guess the first thing I’d do is disconnect the battery and reset all of the electronics. Then I’d charge the battery to full charge with a battery charger, clean all the terminals, reconnect the battery, and see if that fixes the problem. It very well might. If it doesn’t, back to the drawing board, might well be some electronic component in the security or BCM as noted has failed. Or it could be something more simple, like a corroded connector or ground connection that has come loose. If it does fix the problem, but the problem returns a few days later, suspect a battery or alternator problem.
If the BCM controls all those things you mention are having trouble (and I wouldn’t be surprised if it does) I agree with your thinking about the BCM possibly causing the troubles. I suppose you could pull the fuse to it when you park the car to see if that keeps the trouble from happening. You might not be able to use the keyless entry system if you do that.
I would go with low battery or bad ground connection. Clean battery connections and ground connections and see if it clears up.