Yesterday, I noticed the horn did not work in my S85. While driving, I rebooted the dash and the center console and it still would not work. I had no trouble pushing the horn, just no noise. Upon arriving home, I was able to activate the horn with the iphone app. Once home, I again went to reboot the dash and console and still no horn. This am, 10 hours later, the horn now works. I tried to look for posts on this and found no answer. I obviously will continue to monitor this and bring it to Tesla's attention at the next service. Has anyone experienced a similar problem and/or does anyone know what is going on?