So mine was doing this exact thing intermittently. I took my truck to the dealership for an oil change a while back and told them what it was doing. They looked and said that if it's not doing it at that time, they can't diagnose. They said swing in when it's doing it, and they will take a look at it. Today it started as I was driving past the dealership (got lucky, I guess). I stopped by, they took it in the back for 15 mins, came back out, said I needed a new radio, charged me $125+tax diagnostic fee, and gave me a quote for $820.81.
If anyone has any alternatives, I'm all ears.