The info on my CC rig is in the "Compressed Air" discussion of the "Automotive" section of the CC Manual.
It does say there is a Chime and Light Alert when the air pressure is below 65 PSI.
1995 38' CC Magna #5280
C8.3L 300hp Cummins, 31,000lbs
Gillig Bus Chassis 05 Jeep Wk