They upgraded the firmware in the ACM. Forscan can't do that. I believe you need IDS or some other Ford licensed software. They charged me $99 "diagnostic" even though I figured it out and told them exactly what to do. Just have them apply SSM 46129 as quoted above. Well worth $100 for me, I bought the car a week ago and was having serious buyers remorse until I got this fixed....and a few other mods, but this one was really driving me crazy. Love it now.
One of the "service advisors" even tried to convince me the static is normal, his sister's car has it. They tried "everything" and you just get used to it. I said I can't agree that it's normal, maybe common, but definitely not normal. I bet he's gonna fix his sister's car and pretend he figured it out.