US Patent 8161808 Exhaust treatment diagnostic system and method

A method and system for monitoring operation of an exhaust treatment system of a diesel engine includes a dosing system including an injector for injecting an injection fluid and a pump for pressurizing the injection fluid. The system also includes a pressure sensor in communication with the dosing system generating a pressure signal. The system further includes a control module that determines a pressure error signal in response to the pressure signal and generates a fault signal in response.