Control system for secondary air valve supplying air to exhaust gas catalytic converter supplies excess pressure to actuator chamber to seal valve during onboard diagnosis

摘要

The control computer (1) receives lambda signals temperature signals, engine speed signals and load signals. It is connected to a switching valve (3) with an air line (21) connected to the operating chamber of the secondary air admission valve (6). A pump (2) draws air from the air cleaner (4) and passes it through a line to the secondary air control valve. The valve controls admission of air to the exhaust pipe (17) to burn hydrocarbons and carbon monoxide in the catalytic converter (30).