Could someone please tell me what the A.I.R. system is. I was checking out a fuse in the block under the hood today, and found that a large fuse at the top of the block was missing. According to the manual the missing fuse goes to the A.I.R. system. I have only had my 2002 Escalade for a month, so I'm still learning about it but I want to have all systems working properly. Thanks for the help.