One of Saber automatic washes has an issue where every few washes the butterfly arms will close on the vehicle. The arms close right as our tri-foam cycle is about to begin. We've looked at the butterfly collar and prix sensor and they seem to be fine. The motor and gear box are fairly new so it most likely isn't either of those. Could it have something to do with the photo eye sensors or the sonar sensors? Has anyone else ever had an issue like this? Thanks for any responses.