Code Definition

P0412 — Secondary Air Injection System Switching Valve A Circuit Malfunction

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

About P0412

P0412 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 P0412 is stored, the module has detected an electrical-circuit fault in the wiring, connector, or driver associated with the named component.

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 P0412 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 an electrical fault in the control circuit for Secondary Air Injection (SAI) Switching Valve A. This valve controls the flow of fresh air into the exhaust system to reduce emissions. A malfunction in the circuit can lead to improper air injection operation.

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