Patent ID: 6935625

Claim:
An air suspension control system for a vehicle comprising: a source of pressurized air; an air spring; a height control valve having an air inlet port connected to said source of pressurized air, an exhaust port connected to atmosphere and an air spring port connected to said air spring, said height control valve operable to selectively couple between: the air inlet port and the air spring port, the exhaust port and the air spring port, or a neutral position where the air inlet port, the air spring port, and the exhaust port are isolated from each other; an air restriction valve fluidly coupled between said height control valve and said air spring, said air restriction valve operable to selectively open and close communication between said height control valve and said air spring; a first control input for controlling said height control valve, said first control input based on a first parameter; a second control input for controlling said air restriction valve, said second control input based on a second parameter, said second parameter being different from said first parameter; wherein said first parameter comprises a measured vehicle height and said second parameter is selected to control said air restriction valve such that air losses in the air suspension control system are minimized.