Patent ID: 7658069

Claim:
A method for monitoring and diagnosing an air charger system for an engine assembly having pre-existing sensors, said method comprising the steps of: providing a secondary air charger system having a turbine in fluid communication with the intake flow path of said engine assembly, and a compressor in fluid communication with the path of exhaust gas flow of said engine assembly, said turbine and said compressor operatively coupled to one another; providing a control unit for monitoring a plurality of operating conditions of said secondary air charger; providing at least one of said pre-existing sensors, at least one known condition, and a combination thereof, to be used for monitoring of said plurality of operating conditions of said secondary air charger; providing a throttle in operative fluid communication with said turbine for controlling the flow through said turbine, wherein said at least one known condition is a known commanded position of said throttle; providing one of said pre-existing sensors to be a mass air flow sensor, said mass air flow sensor being located upstream of said throttle and said secondary air charger system; said control unit calculating an expected value of a selected operating condition based upon at least one of said plurality of operating conditions; comparing said expected value and at least another of said plurality of operating conditions; and diagnosing a fault condition, if present, based upon said expected value and said at least another of said plurality of operating conditions being outside a predetermined tolerance.