Air Bypass Circuit

This circuit is used only on California vehicles (except Eagle). In addition to the Federal components, this system consists of an air bypass valve, diverter solenoid, extended idle circuit, two-way and reverse delay valves. This system is controlled and activated by the Computerized Emission Control (CEC) system.

The air bypass valve releases system air pressure to the atmosphere when the diverter solenoid is energized by the Open Loop 3 switch of the CEC. However, for the first 75 seconds of Open Loop 3 (warm idle) operation, the extended idle relay switch cuts current flow to the bypass valve to prevent dumping of the system air. After 75 seconds, the idle relay switch turns off and the air pressure is dumped to the atmosphere.

The two-way and reverse delay valves are used to prevent loss of vacuum during acceleration. A thermal vacuum switch is located in the air cleaner to block system vacuum below temperatures of 50° F.