So one day the backup assistant sensors stopped working. I have version with no camera, so just the beeping stopped completely. I was driving with it like that for quite some time since I have good estimation where obstacles are around vehicle but it was annoying. Then one day I was changing lights and I unplugged the battery for like 1/2 hr. When I pulled it in, set the time and radio, suddenly the sensors started working again. I had no issues with them since then for past two years. System just needed a good old reboot.