DTC codes / P34xx · Auxiliary emission controls / P3479
P3479 indicates that the powertrain control module (PCM) has detected a low-voltage condition on the electrical circuit that controls the exhaust valve for cylinder 10. This circuit typically operates a solenoid or actuator that adjusts exhaust flow, and a low signal means the PCM sees voltage below the expected range, which can prevent the valve from functioning correctly.
Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.
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