Back in 2006 HUMTECH made a post here
http://www.elcovaforums.com/forums/s...air+suspension about "If this is an early model H-2 with A single stage compressor there is a programming update to address your concern, talk to your dealer tech and he should know about it. Likely the service consultant or service manager will not have the info."
Maybe yours hasn't had the update ?
Good luck, Ed