Abstract: A secondary air system comprising a variable speed air pump and a gated check valve connected between the variable speed air pump and an IC engine. The gated check valve has two ports, and generally, a first of the two ports is connected to a first bank of engine cylinders, and a second of the two ports is connected to a second bank of engine cylinders. The system further comprises a controller for controlling the speed of the variable speed air pump, and the positioning of the gated check valve. The gated check valve is operable to fully close air flow to both ports, fully open air flow to one of the two ports, or variably split air flow between the two ports.

Abstract: A diagnostic test for a secondary air system comprising an air pump, a first mass air flow sensor connected to the air pump and a first check valve connected to the first mass air flow sensor. A first testing phase is disclosed comprising a first delay period and a first testing period, wherein the air pump is activated. A second testing phase is disclosed comprising a second delay period and a second testing period wherein the first check valve is opened. A third testing phase comprising a third delay period and a third testing period is disclosed wherein the first check valve is closed. A fourth testing phase is disclosed comprising a fourth delay period and a fourth testing period wherein the air pump is deactivated. An optional fifth testing phase is also disclosed comprising a fifth delay period and a fifth testing period wherein the air pump remains off but the check valve is reopened and engine RPMs are increased.

Abstract: A diagnostic test for a secondary air system comprising an air pump, a first mass air flow sensor connected to the air pump and a first check valve connected to the first mass air flow sensor. A first testing phase is disclosed comprising a first delay period and a first testing period, wherein the air pump is activated. A second testing phase is disclosed comprising a second delay period and a second testing period wherein the first check valve is opened. A third testing phase comprising a third delay period and a third testing period is disclosed wherein the first check valve is closed. A fourth testing phase is disclosed comprising a fourth delay period and a fourth testing period wherein the air pump is deactivated. An optional fifth testing phase is also disclosed comprising a fifth delay period and a fifth testing period wherein the air pump remains off but the check valve is reopened and engine RPMs are increased.

Abstract: A secondary air system comprising a variable speed air pump and a gated check valve connected between the variable speed air pump and an IC engine. The gated check valve has two ports, and generally, a first of the two ports is connected to a first bank of engine cylinders, and a second of the two ports is connected to a second bank of engine cylinders. The system further comprises a controller for controlling the speed of the variable speed air pump, and the positioning of the gated check valve. The gated check valve is operable to fully close air flow to both ports, fully open air flow to one of the two ports, or variably split air flow between the two ports.