The door jam switches are built into the door latches on that car. They have a history of having sticking problems. here's a procedure that usually works very well.
Get a can of spray lube like WD40 or something like it and has a straw on the nozzel. Spray it generously up into the latch mechanism. Now open and close the door numerous times to work it in. Repeat this process several times. Since you don't really know which door is causing the problem, you should do all of them. It's usually caused by the most frequently used door but it's not gauranteed to be that one.
If the computer thinks one door is open, it likely won't energize the locks.
Then you still have a problem with one of the door jam switches.
If I were you, I would try a little harder to get it working because your alternative is that the dealer will have to use a scan tool to determine which one it is and replace it.
I'm trying to give you a way to avoid that.
OK, I don't believe the keyless entry is going to lock the doors as long as it thinks one is still open but if you want the location of the module, here it is.
It's called the Vehicle Security Module aka: GEM module and it's located behind the dash, right in back of the radio and heater controls.
Here's what it looks like.