: Something is probably wrong with the "pin switch" that controls the dome light. It also tells the door lock module when the door is closed. If it thinks the door is open, it won't lock the doors. You can notice this by opening the driver's door and trying to lock it while it is still open. The locks will go down and then immediately unlock. Try removing the switch and then cleaning it. If it is the newer style that is built into the latch, on the body side, let me know because I think I found a TSB on this subject. There is some kind of corrosion problem and the cure is a new, revised latch/switch assembly. Hope this helps.