There isn't a fuse that affects just the door ajar sensors. Other stuff would be not working as well.
You probably have a latch that got some dirt or something stuck in it. Spray the door latches one by one with WD-40 and see if that helps.
If that doesn't work, the service manual calls for disconnecting each sensor in turn to see if that fixes the problem. Since I don't know where all of the sensors meet up, I would probably have to take all of the doors apart to disconnect the sensor on each latch until you find the problem. (I just did this on my rear hatch for my wagon and now I have Auto Locks again! Kind of troublesome though...)