I have a 05 Tribute with and intermittent Door Ajar light coming on. It's been driving me crazy. Tried the WD-40 trick but it didn't work. I was able to put the vehicle in diagnostic mode using the Trip / Reset button and cycling down to #31 - Door. With all the doors closed, the diag display shows "Door - C". As I open each door, the only one that change the display is the drivers side door. When I open the drivers side door, the dig display changes to "Door - A". When I close the drivers side door, the diag display changes back to "Door - C". None of the other doors change the display when opening and closing each door. What is the chance of having 5 bad door sensors?

 

Have the same problem with my '05 Tribute. Could not figure out which door it was and the alarm would randomly go off. Took it in to have a tech hook up his scanner and tell me it's the rear passenger door, the sensor is $150 and the labor was another $200. I just popped the door panel, cut the wires and tied them together to close the circuit. No light, or alarm, but also no power lock on that door. It's a quick temporary fix to shut the alarm up until I buy a new sensor.