DTC P0410: Secondary Air Injection System: Description

The secondary Air Injection (AIR) system is designed to lower the exhaust emission levels after engine start up. The Powertrain Control Module (PCM) commands the AIR pump relay on by supplying a ground to the relay control circuit. This action energizes the AIR pump which forces fresh air into the exhaust stream. The PCM also commands the AIR vacuum control solenoid valve on by supplying a ground to the control circuit. With the AIR solenoid activated, engine vacuum is then applied to the AIR shut-off valves. Fresh air from the AIR pump then enters into the exhaust stream. The air that is introduced into the exhaust system accelerates catalyst operation reducing exhaust emission levels. When the AIR system is inactive, the AIR shut-off valves prevent airflow in either direction.

After a warm start up the PCM can detect an AIR system airflow fault by monitoring the Heated Oxygen Sensors (HO2S) and short term Fuel Trim (FT) values. This is a passive test. If the passive test indicates a pass, the PCM takes no further action. If the passive test fails or is inconclusive, the PCM diagnostic will proceed with an intrusive or active test. The PCM will command the AIR system on during Closed Loop operation. The active test will pass or fail based on the response from the HO2S. The active test consists of 3 tests run at 3 second intervals. A lean HO2S response indicates that the secondary AIR system is functioning properly. An increasing short term FT value also indicates a normal functioning system. The AIR diagnostic consists of the combination of the passive and the active tests. If the PCM detects that the HO2S and short term FT did not respond as expected on bank 1 and bank 2, DTC P0410 sets.

The AIR system consists of the following items:

• The AIR pump.
• The shut-off valves.
• The vacuum control solenoid valve.
• The system pipes/hoses.
• The AIR pump relay, fuses, and related wiring.