I have a 2012 Town and Country that I purchased new. I keep the car in my garage so there is no need to lock the car. Periodically I have noticed that the car is locked. I never lock it in the garage but I attributed this to my accidentally pushing the button on the key fob.



Yesterday, I left the keys on the dash board while the car was parked in my driveway. When I returned several hours later the car was locked.

At this point I am assuming that the car picks up ambient signals and automatically locks itself. Has anyone else had this experience?

 

Yes, I've had this effect in reverse. My Jag kept unlocking it's boot/trunk when parked in a certain place 2 miles away from the house. I parked it round the corner instead -- prob. disappeared.
Sources of interference with the microwave signal from your keyfob are:
1) Someone else's keyfob nearby.
2) A microwave cooker (very high power and heavily mains-modulated at 2.45GHz.).
3) A wireless lan computer set-up.
4) A mobile phone.

All the above operate at the same microwave frequency, low-power keyfobs etc. requiring no licence. The fact that your keyfob is digitally modulated doesn't mean it can't be interfered with. The data-protection algorithm will be too simple.

There is the possibility your microprocessor board has acquired a glitch, disconnecting the battery -ve for a few minutes will establish. That's the easiest one to get out of the way first.

Leedsman.