I contacted three different Hyundai dealer service departments. None of them knew what I was talking about when mentioning the TSB - typical. They all said they would "speak with a technician" and call me back. Guess what? No calls back. I emailed Hyundai corporate and at least got a case number. Since the last time the car was serviced for a knock sensor issue was prior to 2015 I doubt this ECU update was implemented. I'm going to take a chance and schedule a service visit at a nearby Hyundai dealership. Corporate said to use the case number. Perhaps that MIGHT result in getting the update at no charge. My son thinks everything is peachy because the light stays off MOST of the time. To me, if it comes on at all due to faulty programming it is unacceptable.