Electric Divert/Electric Air Switching Valve (EDES)
The Electric Divert/Electric Air Switching Valve (EDES) combines the functions of both the air diverter valve and air switching valve into one integral component.
The ECM controls the air divert valve by controlling the vacuum solenoid in the EDES valve. The EDES switches air pump air as follows:
- To the exhaust manifold during "open" loop.
- To the catalytic converter during "closed" loop.
- To the atmosphere or air cleaner on closed throttle, deceleration, rich running, or high air pump pressure.
The EDES valve will also divert air whenever ECM recognizes a problem and sets check engine light.
The ECM also controls the air switching function of EDES valve by directing air injection flow to exhaust ports during cold engine operation (open loop) and to catalytic converter during warm engine operation (closed loop).