Air Injection: Testing and Inspection

NOTE: This system should be diagnosed in conjunction with the "Computerized Emission Control" (CEC) system.

Air Bypass Circuit Functional Test
1. Disconnect hoses from ports A and B of air switch valve. Hose A is connected to air injection manifold and hose B is connected to catalytic converter.
2. Start engine and allow to reach normal operating temperature, then turn engine off.
3. Restart engine and increase speed to 15O0 rpm. Air should flow from port A of air switch valve for about 30 seconds, then flow from port B.
4. If there is no air flow as described previously, check base of diverter valve for air exhaust.
5. If air does not flow according to step 4, increase engine speed to 1500 rpm and check that vacuum is being applied to diverter valve. If there is vacuum, replace diverter valve and recheck. If there is no vacuum, check divert solenoid.
6. If air does not flow, inspect air pump for proper operation.
7. If airflow from air switch valve is normal, depress accelerator pedal to floor, then return engine to idle and check base of diverter valve for air flow. If there is air flow, circuit is operating normally. If there is no air flow, check diverter vacuum hose for vacuum. If there is no vacuum, replace diverter valve. If there is vacuum, check divert solenoid.

Air Switch Circuit Functional Test
1. Disconnect hoses from ports A and B of air switch valve. Hose A is connected to air injection manifold and hose B is connected to catalytic converter.
2. Start engine and allow to reach normal operating temperature, then turn engine off.
3. Restart engine and increase speed to 1,5O0 rpm. Air should flow from port A of air switch valve for about 30 seconds, then flow from port B.
4. If air flows from both ports of air control valve, replace the valve and retest system.
5. If air flows from port B only, proceed as follows:
a. Remove vacuum hose and check for vacuum during the first 30 seconds of operation.
b. If no vacuum is present, replace air control valve and retest.
c. If vacuum is present, the [1][2]upstream solenoid is faulty.
6. 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.
7. If air flows only from port B, remove vacuum hose and check for vacuum during the first 30 seconds of operation. If there is no vacuum, replace air switch valve and recheck. If there is vacuum, check [1][2]upstream solenoid.
8. If air flow is normal, depress accelerator to floor, then return engine to idle and check base of diverter valve for air flow.
9. If air flows, system is operating normally. If there is no air flow, check diverter valve vacuum hose for vacuum. If there is no vacuum, replace diverter valve. If there is vacuum, check divert solenoid.