Air Injection: Testing and Inspection
SECONDARY AIR INJECTION - AIRFig. 1 Air Pump:
Monitoring Procedure
This diagnostic operates only once per ignition cycle, during the first long duration hot idle period after engine start. Air injection operation is started and the change in AFT closed loop control value is monitored, After a while, if this value does not change by at least a pre-determined value, then the secondary air system malfunction judgement is made. The diagnostic trouble code (DTC) is stored if the failure judgement is made on two successive ignition cycles.
If the fuel system diagnostic has flagged a lean failure on both banks, the air injection switching valve circuit failure judgment is made. The DTC is stored if the failure judgement is made on two successive ignition cycles.