2001 Park Avenue doors won’t unlock

[PK.AVE.JIM]

I own a 2001 Park Avenue that has had some strange door lock problems. Since I bought it about ten years ago, when I get out and try to lock it with the remote, it will lock and unlock, lock and unlock a random number of times and always ends up unlocked. At seemingly random times it will do this lock and unlock without any input, just spontaneously. Later, a rear door locked and will not unlock with the remote or manually. Later, the other rear door did the same thing and then the front passenger door. I could not unlock these doors by any means. The driver's door seems immune so far, maybe because it has a key lock mechanism. I removed the door panel on the passenger side and manipulated the mechanism at the lock and got it to unlock once, then I locked it and haven’t been able to unlock it again. Because of the structure of the metal door, I can't see the mechanism at the lock and the 2100 page 2001 Park Avenue Service Manual doesn't have a clear diagram of it nor the Haynes or other parts store manuals.
I want to disconnect the electronic mechanisms and lock and unlock manually from inside.

Is anyone familiar with this type of problem or have a good diagram of the front and rear door locking mechanisms?