06 ford Taurus door ajar problem?

I got a 06 Taurus and when I go to start the car my screen says passenger door ajar but the door is closed and locked and suggestions

The switch (sensor) that detects whether or not the door is closed is mounted to the door latch inside the door. Its not an expensive part but the labor to replace it can add up. The door panel must be removed as well as the latch itself which takes time. My guess is an experienced mechanic should be able to do it in an hour, a DIYer considerably longer, but cost would depend on labor rates in your area.

There's a small electrical switch in each door that tells the computer weather that door is open or closed. Most Fords have the switch inside the door back by where it locks to the door post.