The P0415 code indicates that the engine control module (ECM) has detected a malfunction in the electrical circuit of the secondary air injection system switching valve 'B'. This valve controls the flow of fresh air into the exhaust to reduce emissions during cold starts. The fault is typically an open, short, or high resistance in the valve's circuit.
The solenoid or valve itself has failed internally, often due to an open coil or mechanical sticking, preventing proper operation.
Chafed, broken, or corroded wires and loose or corroded connectors in the valve circuit cause high resistance or open circuits.
A blown fuse in the secondary air injection system circuit can cut power to the switching valve, often due to a short or overload.
Wiring insulation damage can cause the valve control wire to short to ground or to a power source, leading to circuit malfunction.
An internal ECM driver failure is a rare cause; only consider after all other circuit and component checks are exhausted.
Yes, the vehicle is generally safe to drive as this code does not affect engine performance or safety systems. However, it may cause a failed emissions inspection.
In the vast majority of cases, no. The PCM is rarely the cause of this code. The switching valve itself or wiring issues are far more likely. Only after a complete diagnosis ruling out all other possibilities should the PCM be suspected.
It pumps fresh air into the exhaust manifold during cold starts to help burn unburned fuel, reducing hydrocarbon emissions and warming up the catalytic converter faster.
No, a P0415 code typically does not cause any noticeable change in engine performance, fuel economy, or drivability. It is strictly an emissions-related fault.