just bought a 2009 navigator and everything was great until i started playing around with the different features. I was scrolling through the info menu figuring how things worked when I came upon the air suspension on/off. I switched it off then scrolled through the menu again and turned it on, Now the back end is sagging and i'm getting a check suspension message on the info screen. I don't hear the compressor running anymore either, The compressor was replaced a few months ago. Is there a way to reset the system?