Code Definition

P0411 — Secondary Air Injection System Incorrect Flow Detected

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0411

P0411 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0411 is stored, the module has detected a signal or supply voltage lower than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0411 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The ECM/PCM sets this code when it detects that the secondary air injection (SAI) system is not delivering the expected amount of airflow into the exhaust. The SAI system injects fresh air to help reduce emissions by accelerating catalytic converter warm-up. Insufficient or excessive flow can result from blockages, valve failures, or pump malfunctions.

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