OBD codes / P0413
P0413
ModerateSecondary Air Injection System Switching Valve A Circuit Open
P0413 is low urgency for safety — the secondary air system only works during cold-start warmup, so the car drives normally once warm. The cost of ignoring it is higher cold-start emissions and a failed emissions test, so fix it at your convenience but before inspection time.
What this code means
P0413 means the computer found an open circuit — a break in electrical continuity — in the control circuit for the secondary air injection switching valve. The secondary air system pumps fresh air into the exhaust for the first minute or so after a cold start, which helps the catalytic converter light off quickly and burns leftover fuel in the exhaust. The switching (or combination) valve is what lets that pumped air into the exhaust and then seals it off. An open circuit usually means a failed valve solenoid, a broken wire, a blown fuse, or a corroded connector rather than anything mechanical. Because the system only runs briefly on cold starts, you often notice nothing at all except the light. These systems live in a harsh spot near the exhaust, and moisture-related corrosion in the valve, pump, and connectors is a common failure pattern.
Symptoms you might notice
- Check-engine light, often with no drivability change
- Occasionally a rough or noisy cold start
- Secondary air pump not heard running after a cold start
- Failed emissions test
What it costs to fix
Varies by vehicle — get it diagnosed.
The repair cost for this code depends too much on your exact vehicle and the underlying cause to quote a meaningful range. Confirm the cause first so you only pay for the fix you actually need.
Diagnose P0413 for my vehicle →Frequently asked
Is it safe to drive with P0413?
Yes. The secondary air system only operates for a short period after cold starts, so this code doesn't affect normal driving or safety. It's an emissions issue, so handle it before your next inspection.
What does 'circuit open' mean in P0413?
It means the computer sees a break in the electrical path to the switching valve — like a light switch that's disconnected. Common culprits are a failed solenoid coil, a broken wire, a corroded connector, or a blown fuse, not usually a mechanical valve failure.
What does the secondary air injection system do?
It pumps fresh air into the exhaust right after a cold start so leftover fuel burns off and the catalytic converter heats up faster. Once the engine warms up, the system shuts off and stays off for the rest of the drive.
Why do secondary air parts fail so often?
The valves and plumbing sit close to hot exhaust and also collect condensation, so corrosion is common with age. When one part fails it's worth inspecting the pump, valves, and connectors together, since moisture that killed one component often affects the others.
Seeing P0413 on your car? Get a diagnosis specific to your exact year, make and model.
Diagnose P0413 for my vehicleRelated trouble codes
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Generic OBD-II reference. Manufacturer-specific behavior varies — confirm with a scan tool and, for safety-related codes, a professional inspection.