A couple of days ago my front driver's side sensor kept going off, even when I wasn't close to anything or while I was driving on the open road. Just checked it last night, and it's gone- not sure whether it's pushed in or it fell off. Has this happened with anyone else?

 

Happened to me exactly once when I was stopped at a light long ago and haven't experienced it since.

Is this an ongoing thing and does it happen when you're moving? Next time you start up the car try disabling and reenabling the parking sensor feature from the dash. That might help. If it persists maybe it is failing and needs repairing/replacing.

 

Probably pushed in and is detecting the bumper

 

Has happened to me on occasions when the car is dirty (not filthy) but just enough for something to trigger the sensor into thinking something is present. Sounds crazy I know but the two times it's happened I took some spray wax (always keep some handy in the trunk) to the side in question and problem was resolved. Hope it's that easy for you as well - good luck.

 

Recently a pheasant jumped out in front of the car when I was doing about 90 km/h. It hit the bumper on the right hand side, pushing the fog light and parking sensor out of their holders and left them hanging loose behind the bumper. It was only when the parking sensor started howling that I realized the pheasant had done some damage. The sensor could be pushed back into its hole (it's a press fit), but unfortunately the fog light had broken the bracket. Now fixed.