P0411

Circuit Description
The purpose of the Secondary Air Injection (AIR) system is to reduce Hydrocarbon (HC), the Carbon Monoxide (CO), and the Oxides of Nitrogen (NOx) exhaust emissions by causing any combustible gases in the exhaust to re-burn. This also causes the catalytic converters and the heated oxygen sensors to reach the normal operating temperatures more quickly, thus Closed Loop operation occurs earlier.

When the engine is started, the ECM commands the AIR pump relay and the AIR Cutoff Valve Vacuum Control solenoid on, injecting clean air into the engine exhaust ports. The ECM switches the AIR system off when the oxygen sensors become active. The AIR Cutoff Valve prevents air from being drawn into the system when the AIR pump is off. The vacuum to the valve is controlled by the AIR Cutoff Valve Vacuum Control solenoid. A check valve close to the engine prevents hot exhaust gases from backing up into the AIR system.

Conditions for Running the DTC
^ The following DTCs are not set: P0110, P0115, P0116, P0130, P0131, P0132, P0134, P0150, P0151, P0152, P0154, P0171, P0172, P0174, P0175, P0300-P0306, P0412, P0418, P0440, P0442, P0443, P0446 or P0455.
^ The IAT is between 5°C and 40°C (41°F-104°F).
^ The ECT is between 18.8°C and 105°C (65.8°F-221°F).
^ The engine is at idle.
^ The vehicle speed is 0 km/h (0 mph)
^ The AIR system is active.

Conditions for Setting the DTC
The ECM has determined that reduced or no secondary air flow is present.

Action Taken When the DTC Sets
The ECM illuminates the Malfunction Indicator Lamp (MIL) and records the operating conditions in the Freeze Frame on the second consecutive drive trip that the diagnostic runs and fails.

Conditions for Clearing the MIL/DTC
^ The ECM turns off the MIL after three consecutive drive trips that the diagnostic runs and passes.
^ A History DTC clears after forty consecutive warm-up cycles in which no failures are reported by this diagnostic or any other emission related diagnostic.
^ The ECM battery voltage is interrupted.
^ The scan tool clears the MIL/DTC.

Diagnostic Aids

Notice: Refer to J 35616-A Connector Test Adapter Kit Notice in Service Precautions.

^ Use the Connector Test Adapter Kit J 35616-A for any test that requires probing the ECM harness connector or a component harness connector.
^ Using the Freeze Frame data may aid in locating an intermittent condition. If the DTC cannot be duplicated, review the information in the Freeze Frame. Try to operate the vehicle within the same freeze frame conditions (the RPM, the MAF, the vehicle speed, the temperature, etc.) that were noted. This process may help in order to recreate the malfunction.
^ Inspect the AIR pump check valve for a restriction or damage.
^ Refer to Symptoms for Intermittent conditions. Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to the step numbers on the diagnostic table.
14. Inspect the check valve. A check valve that is stuck closed can cause no air flow. Check the hoses after the check valve for evidence of heat damage. A heat damaged hose indicates that the check valve is stuck open allowing exhaust gas back into the AIR system.
19. The AIR pump has a filter element on the inlet side. Check for a blocked pump inlet before replacing the pump.