I have a noise I can hear when stopped that sounds like an electric motor running from the rear of my 2016 Tahoe LTZ when my foot is on the brake. I assume it is the compressor for the air ride suspension since it is coming from the rear. The weird thing is that it will stay on both with the engine running and after I turn it off until I take my foot off of the brake pedal. It stops when I take my foot off the brake and then starts once I press the brakes again. It also does this when I first start the vehicle, too. I am not sure if it happens while driving because the road noise would be louder than the sound I am hearing. Is it possible that the compressor would somehow be triggered by the brake pedal? Is there something it could be besides the compressor?