I have a 2017 Malibu LT. I bought it new and it now has about 10,000 miles. It occasionally makes a loud buzzing sound which seems to be coming from under the dashboard. This noise started soon after I bought the car. It sometimes occurs when driving and can be quite a distraction. It usually happens when I pull into the garage and turn off the ignition. Turning off the radio has no effect. Opening the car door does not stop it. Putting my foot on the brake and the noise ceases, remove my foot and the sound resumes. I have just had to leave the car with the noise continuing. It eventually will stop. What is the connection with the brake and some other electronic activity?
My local Chevrolet dealer cannot resolve this problem. In their defense, it has never made the noise when it has been in their shop.