Patent ID: 7216552

Claim:
A system for estimating the condition of a compressed air supply system installed on a motor vehicle, the compressed air supply system having a prime mover, a compressor coupled to be energized by the prime mover, a governor controlling engagement of the prime mover to the compressor, an air line from the compressor, a storage tank coupled to receive compressed air from the air line and an outlet air line from the storage tank for connection to a vehicle subsystem requiring pressurized air, the system comprising: an air pressure sensor communicating with the storage tank for measuring air pressure therein and generating an air pressure signal of the measurements; a brake pedal position sensor indicating a brake pedal up or a brake pedal down status; a source of a clock signal; a source of a cycle interval norm for the compressor, a duty cycle norm for the compressor, a maximum air pressure norm for the storage tank, a minimum air pressure norm for the storage tank, norms for pedal up and pedal down leak rates; an information processor having access to the norms, the air pressure signal, the clock signal and connected to receive the status of the brake pedal, and programmed to correlate variance in measurements of the air pressure from the maximum and minimum air pressure norms for the storage tank, variance in duration of charging time for the storage tank from the duty cycle norm, and variance in frequency of charging of the storage tank from the cycle interval norm with at least a first potential or actual fault condition.