Just recently my Buick Park Avenue 2003 model has started sounding the car alarm whenever any door is opened. I cannot figure out how to stop this. Can someone help?

You need to get yourself a service manual at your local parts house to get the wiring diagram to disable it.

All door lock switch inputs run through the drivers door module. Since any door opened sets the alarm, I would look at the drivers door module. It is virtually impossible for all four door lock switches to be bad at the same time. Since they route through the drivers door module, I would have that checked with a scan tool. Either the wire that feeds door lock status to the content theft deterrent module has an open or the driver door module requires replacement. The driver door module is about $600 new, maybe you can pick one up on eBay.

You may try locking and unlocking the drivers door a couple of times with the key. My car did the same thing a couple of times and it quit.

@boba42 ... that's a hell of a lot cheaper than a module and is for sure worth a try.