P0411

P0411-SECONDARY AIR INJECTION SYSTEM INCORRECT FLOW DETECTED

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Secondary Air Injection System reduces hydrocarbon emissions by decreasing the catalyst warm up time. During a cold engine start, after a short diagnostic time out, typically two to three seconds, the Powertrain Control Module (PCM) commands the Secondary Air Pump on for approximately 20 seconds. The Secondary Air Pump supplies air to the exhaust manifold through the Secondary Air Pump Valve, a one-way check valve. This additional air introduced to the exhaust flow aids in the warm up of the catalyst.

- When Monitored:
The Secondary Air Pump is on.

- Set Condition:
Actual air flow is less than the expected air flow.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. DTC IS ACTIVE

WARNING: The normal operating temperature of the exhaust system is very high. Never work around or attempt to service any part of the exhaust system until it has cooled. Special care should be taken when working near any part of the exhaust system. The temperature rises to a high level after a short period of engine operating time.

NOTE: Diagnose and repair any Secondary Air Injection System sensor signal or relay control circuit DTCs before proceeding with this procedure.

1. Turn the ignition on.
2. With the scan tool, select View DTCs and review the DTC environmental data for this DTC.

Is the good trip counter greater than 0?

Yes

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related, splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.

No

- Go To 2

2. AIR INJECTION SYSTEM COMPONENT INSPECTION

NOTE: When a leak has occurred, a whistling noise may be present in the Secondary Air Injection System where the air is escaping from the system. Listening to the system while the Secondary Air Pump is commanded on may aid in diagnosis and the location of any leaks. Do not allow the Air Pump actuation to run for more than 30 seconds at a time. Pump damage may occur. Allow the pump to cool down for at least 10 minutes between actuations.

1. Turn the ignition off.
2. Inspect the Secondary Air Pump Assembly, the Secondary Air Pump Valve, and the connection tubes between them.
3. Look for damage, obstructions, leaks, or any condition that would obstruct or interfere with air flow between the components.

Were any problems found?

Yes

- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related, splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test.