P0415 Code: Secondary Air Injection (AIR) Switching Valve B Circuit Malfunction
🟠 Moderate severity · drivable
Drivable — this affects cold-start emissions, not drivability.
What P0415 means
The circuit for the secondary air injection switching valve B isn't working right. This valve opens to let the air pump push fresh air into the exhaust during cold start, helping the catalytic converter warm up faster.
Symptoms
- Check engine light is on
- Possible failed emissions test
- Possible air leak noise
- No driving symptoms
Common causes
- most common: Faulty switching valve or its solenoid
- common: Damaged wiring or connector
- less common: Blown fuse or faulty relay
How to fix it
| Fix | DIY? | Typical cost |
|---|---|---|
| Check the fuse and relay for the AIR system | Yes | $0–60 |
| Replace the switching valve | Yes | $50–150 |
| Repair damaged valve wiring | Mechanic | $50–150 |
Frequently asked questions
Can I drive with a P0415 code?
Yes. It affects cold-start emissions, not drivability, but fix it before an emissions test.
What is the most common cause of P0415?
A faulty switching valve or its solenoid, or a wiring problem in the valve circuit.
How much does it cost to fix a P0415?
Typically $50–$150 for a new switching valve; a fuse or relay is cheaper.
Related codes
P0412
P0412 Code: Secondary Air Injection (AIR) Switching Valve A Circuit Malfunction
P0416P0416 Code: Secondary Air Injection (AIR) Switching Valve B Circuit Open
P0417P0417 Code: Secondary Air Injection (AIR) Switching Valve B Circuit Shorted
Updated 2026-08. This page is informational and not a substitute for professional diagnosis.