General Description

Certain vehicles may be equipped with a Secondary Air Injection (AIR) System. This system is used to lower tail pipe emissions on start-up. The PCM grounds the AIR pump relay control circuit, which energizes the AIR pump. The PCM also grounds the AIR Solenoid Valve control circuit, which energizes the AIR Solenoid Valve. The PCM enables both circuits when AIR system operation is desired. DTC P0412 applies to the AIR solenoid control circuit. DTC P0418 applies to the AIR pump relay control circuit. DTC P0410 sets if an air flow problem is detected.

AIR System (If Equipped):

The PCM turns ON the AIR system during startup when engine coolant temperature is between 10°C (50°F) and 110°C (230°F). When ECT is above 80°C (176°F) at start up, AIR system operation will be delayed approximately 65 seconds. The AIR pump will operate for approximately 60 seconds. When the PCM turns the AIR pump OFF, it also de-energizes the AIR Solenoid Valve. The closed AIR Solenoid Valve prevents air from being drawn into the exhaust and also prevents the backflow of exhaust into the AIR System.

Refer to DTC P0410 Secondary Air Injection (AIR) System for enabling and disabling criteria.

RESULTS OF INCORRECT OPERATION
If no air (oxygen) flow enters the exhaust stream, HC and CO emission levels will be too high.

Air flowing at all times could increase temperature of the warm up 3-way catalytic converter.