Functionality testing of secondary air injection systems

• Main Author: SAM PRICE
• Format: Patent
• Language: English
• Published: 30.01.2008
• Subjects: BLASTING; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; STEAM ENGINES; WEAPONS

A method and system for detecting faults in a secondary air injection system 10 of an internal combustion engine 11. The system has an air pump 16 for supplying air to the engine exhaust manifold 13 and, a programmable unit 21 for controlling operation of the pump and valve and a pump current draw sensor 31 for sampling electrical current at predetermined time periods spaced over at least on operational cycle of the system. The measured pump current is analysed by the control unit 21 to identify failures in the system. Current draw is measured in three phases of the operational cycle of the system; a first phase with the pump on and the valve closed, a second phase with the pump on and the valve on and a third phase with the pump off and the valve closed.