P0415: Secondary Air Injection System Switching Valve B Circuit Malfunction
What to do
Driveable with no symptom you would notice. Will fail an emissions test.
What this code means
A circuit fault on the second secondary air switching valve. Engines with two cylinder banks often inject air into each bank separately, so a second valve carries the B designation; the diagnosis is identical to valve A applied to the other circuit.
Where A and B faults appear together, look for the shared supply or ground before assuming two valves have failed at once.
Likely causes
Start here
- Faulty secondary air switching valve · moderate
- Corroded or loose connector · easy
- Open or shorted solenoid winding · easy
Less common
- Damaged wiring harness near exhaust heat · moderate
Symptoms
Components involved
Information, not instruction
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Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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