Combination Air Bypass/Air Control Valves

Combination Air Bypass/Air Control Valve:

The Combination Air Bypass/Control valve is located within the air supply line between the air pump and the exhaust manifold, usually toward the rear of the engine near the firewall.

Combination Air Bypass Valve/Air Control Valve Assembly:

The combination valve is normally closed and is equipped with a pressure relief bleed port. The combination valve combines the divert and switching functions into one valve housing.
Manifold vacuum operates the valves when applied the valves vacuum diaphragm chamber. Vacuum application to the chamber is regulated through computer controlled solenoid valves.
The air switching, or bypass, section of the valve protects the converter during open-throttle operation and high temperatures. The divert, or air control, section sends air to the exhaust port during open-loop operation. When the engine moves into closed-loop mode, the valve diverts air flow to an air inlet between the converter beds.
In the event of a malfunction, the pressure relief valve will open to allow air from the air pump the escape.