Park Avenue locking itself

My mother has a 2000 Buick Park Avenue. (Burgundy.) Three times now, it has locked itself. The first time was several months ago, my nephew started it in my brother’s driveway to warm up, and when they went back out, the doors were locked. Fortunately, AAA took less than the four hours it promised to come and break in. In the past few days, it has happened again twice. The first of those times, the key was in the ignition (don’t remember if it was all the way in, or pulled out to stop the bonging when the door was opened). No problem, because we had the second key. I don’t remember if the key was in the ignition the next time. My mother keeps the key in the ignition. (Don’t ask me why.) I feel sure we are not bumping either the door lock or the button on the key when we exit, also, if we did, I think we would hear the locking sound.

Anyone have this experience or have any thoughts? Thanks!

Given a choice between spending money to track down an electrical glitch in a 13-year-old car and simply not leaving a key in the car (at least unless I had the remote or the second key in my pocket), I’d opt for the second choice.

By the way, if the car is ever stolen with the key in the ignition, there’s a reasonable chance that her insurance company won’t pay anything.

Thanks, I’m with you! Not sure I can convince her to change her habits. (The key is only in the ignition when the car is in the garage and the door is always down.)

I was curious why you mentioned it is “Burgundy” . Do you mean this is its color? Or that is the option package?

There have been other posters here who have complained of this problem, not on Buicks necessarily. I think the problem is usually that some electronics gadget in the security system has gone on the fritz and needs to be replaced. The only other thing I can think of is that some electrical intereference is doing it. One time I had a garage door that would open by itself. Turned out it was the lady next door using her sewing machine that was doing it.

Hold on to your wallet. You will probably need a dealership to solve this one. Best of luck.

Why not have spare keys made. If the key is in the ignition switch anyway, there should be a couple extra keys available all the time. I carry a key in both of my pockets because I don’t like walking or freezing half to death. I make mistakes but I don’t want to suffer from them any more. It was easier when I was 19.

With this new problem, Mom cannot leave the keys in the car. That is obvious to all of us including Mom.

Thanks for all the responses!

OK, here’s a long shot to try if you want. When you use the key on the driver’s door, all the doors will lock. There is a switch connected to the door lock on the drivers door that may be bad or shorting out due to rust, wear, etc. If you take the door panel off, you can either check the switch or disconnect the wire so that it can’t activate the door locks anymore. I mention this because I had trouble with the door handle on one of my Buicks activating the interior lights at will and draining the battery. So after some age, it would be a likely problem area.

The remote access controller should be in the trunk under the rear deck. This receives the signal from the remote. Then energizes a relay to either lock or unloc the doors. I suppose this could also be bad, or the relay could be energizing. Either one of those though will require going to the dealer to troubleshoot with their test equipment, but something like this isn’t going to show up in normal testing because it all works.

Boy! They sure made the door lock system complicated. But here’s how it works.

The Powertrain Control Module sends a signal to the Body Control Module. Out of the Body Control Module the signal is sent to the Theft Deterrent Module. Inside the Theft Deterrent Module is the reader/exciter for the ignition key. Out of the Theft Deterrent Module the signal is sent to the Drivers Door Control module. The Drivers Door Control module commands over the other three Door Contols Modules.

Before I would even try to troubleshoot this problem, I would first suggest that your mother not leave the key in the ignition switch to if that fixes the problem.


I forgot about the key being left in the ignition, but would the computer command the doors to lock if the key is left in the ignition? Most cars now won’t let you do anything with the key in.

Agree, just put the key on the dash like I do and see what happens and maybe just roll the window down in case it locks.