Sean, my dealer's mechanic had the car but did not understand the problem. I requested we go for a ride together and he now understands the issue. He said the sonar sensors are acting way too sensitively. He said the TSB is not related to my issue. He said the service department would discuss with GM the issue because he would have to follow their authorizations to do this repair under warranty. I am still waiting for a response from GM. I will post again when the repair is done.