Yes!! This is my issue! But my sirius xm if factory and it's making a loud speaking popping sound even when the car is off and we arent around it.it drained my battery the other day. Were you ever ableo figure out the problem?I suspect you'd have mentioned it, but is there a message in the DIC (on the dash) that says something like "Park Assist Off"??? I have an aftermarket Sirius and Bluetooth setup and this (no sound) sometimes happens to me, but I do get that message.