DTC P0410: Secondary Air Injection System: Description

Secondary Air Injection (AIR) pump is used lower tailpipe emissions on start-up. PCM grounds the AIR pump relay control circuit, which energizes the AIR pump. PCM also grounds the AIR combination valve vacuum control circuit, which energizes the AIR vacuum solenoid valve. Vacuum is then applied to both AIR combination valve diaphragms which open the shutoff valves. PCM enables both circuits simultaneously when AIR system operation is desired. When AIR system is active, the AIR pump forces fresh air into exhaust stream in order to accelerate catalyst operation. The AIR solenoid valves replace the conventional check valves. When AIR system is inactive, the shut-off valves prevent airflow in either direction. DTC will set if an airflow problem is detected.