Air Bypass Circuit Functional Test

1. Disconnect hoses from ports A and B of air control valve, then start engine and run until normal operating temperature is reached and turn engine off.
2. Restart engine and run at 1,500 RPM. Air should flow from port A of air control valve. then from port B.
3. If no air flow is observed, proceed as follows:
a. Check diverter valve vents for air flow.
b. If air flow is present, check for vacuum at diverter valve with engine running at 1,500 RPM. If there is vacuum, replace diverter valve and recheck. If no vacuum is present, the divert solenoid is faulty.
c. If there is no air flow from diverter valve vents, check air pump for proper operation and repair or replace as necessary.
4. If air flow from air control valve is normal, proceed as follows:
a. Depress accelerator pedal to floor, then return engine to idle and check diverter valve vents for air flow.
b. If there is air flow, the circuit is operating normally.
c. If there is no air flow, check diverter valve vacuum hose for vacuum. If no vacuum is present, replace diverter valve. If vacuum is present, the divert solenoid is faulty.