Air rider suspension
 

2017 Suburban Premier with air ride and magnetic suspension.

Lately, the cat has been very bouncy and I no longer hear the air ride compressor kick on ever. I'm guessing that at least one of the struts has gone out. How do I determine which one? Using a bidetectional odb scanner, no codes are thrown. Out is it just that the compressor is out and therefore not pumped up?