Parking Sensor Failure

[jenpearman]

Help please? I have a 3 series with factory fitted sensors x4. They were working fine but a few days ago put it in to reverse and the warning sound came on (no pics on dash tho). I changed the fuse and still not working. I have listened for the clicks and all 4 are present. They are also clean. Anyone have any ideas what this can be please?

[stevewak]

What BMW? E46 a known issue. Just had one replaced but beeping has returned. Puzzled technician will swap over to another new one next week to see if that solves it.