'04 Maxx spontaneous unlocking
 

I'm having trouble with the doors spontaneously locking and unlocking while I'm driving my '2004 Maxx. At its worst, it's nearly constant lock & unlock. It happens when it's raining--and I'm living in the Pacific NW, so we're entering the rainy season. Sometimes, it unlocks and locks itself when I'm not even in the car. Also, the inerior lock switch no longer works. Even when it isn't raining, only the driver's door will lock & unlock with the key. The others have to be locked manually.
An independent mechanic said it might be the body control module. All I know is that the dealership is going to charge me upwards of $125 just for a diagnostic. Anyone else experience this problem? Anyone else have an idea what it might be?

Thanks in advance.

I have this problem too!
 

I have a 2005 Mailbu Maxx and I have the same problem! It just started yesterday, I had left my car windows open and I was wondering if it had been the rain that had done it. I don't know why or how but maybe the rain caused a short in some electrical thing? I don't know. Did you ever resolve this issue in yours?

This site seems to have a lot of people with the same problems and there fixes for it. Hope this helps :) Personally I think I might just take out the fuse for mine.

http://www.fixya.com/cars/t1167704-2...axx_electrical

Nikoli_v,

I’m sorry to hear that you’re experiencing issues with your vehicle. Did you replace the fuse in your vehicle? If so, did the issue stop?

Thank you!

Elizabeth, Chevrolet Customer Service

The way I understand it, taking the fuse out is to cut the power to the door locks which will certainly stop the symptom but at the expense of the loss of convenience. As to the fixya dot com website, any insight found there has to be taken with a grain of salt since the problems themselves are usually non-specific and ill-defined.

This is true, but I am heading from 'safe' North Dakota to California for 3 weeks and because of this trip I limited on cash the way it is so I'm willing to suffer the inconvenience to keep my car safe, unless you have a better idea? A quick, cheap fix? This is probably only temporary, and who knows, maybe the problem will stop when I replace the fuse.

In the OP's case (which is before my time on this site), it was probably a door ajar switch intermittently short out. Moisture itself wouldn't do it but salt in solution could allow enough current to flow between the switch contacts. The BCM then senses a door being open and unlocks the driver's door (lockout protection feature). If the current flow is just at the threshold, this can cause the lock to cycle continuously while the vehicle is driven. When the vehicle is parked, the BCM can unlock the door or blow the alarm spontaneously, depending on the model year. If you have the "same problem," you can wait for it to dry out but I'd think it's just a matter of time before the symptoms come back.

Fixed itself!
 

For some strange reason, the doors quit unlocking automatically. I thought that the problem was due to the heavy rain, but have had some equally (some? many! I live in the Pac NW) rainy days with no repeat of the phenomenon. It's a mystery to me.