P0413 — Secondary Air Injection System Switching Valve A Circuit Malfunction
Drive with caution — fix soon.
What P0413 means
This code means the engine computer detected an electrical problem in the control circuit for the secondary air injection switching valve 'A', the valve that directs fresh air into the exhaust at startup. It usually points to a faulty switching valve, a wiring or connector issue, or a problem with the control relay. It's a fairly common code and is typically fixable without major engine work.
Common symptoms
- Check engine light is on
- Rough idle shortly after a cold start
- Unusual noise from the air pump at startup
- Will likely fail an emissions test
- Little to no change in everyday driving
Common causes
- Faulty secondary air switching valve (A)
- Damaged or corroded wiring or connector at the valve
- Failed control relay for the switching valve
- Poor power or ground to the valve circuit
- Faulty engine control module signal (less common)
Typical repair cost
$150 – $600
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0413 code?
Usually yes, since this valve mostly affects cold-start emissions rather than normal driving. The car stays safe to drive, but it will likely fail an emissions test, so plan to have the circuit and valve checked.
How much does it cost to fix a P0413?
Most repairs land between about $150 and $600. A wiring or relay fix is on the lower end, while replacing the secondary air switching valve costs more.
Is a P0413 code serious?
It's not a safety emergency and rarely strands you, but it means part of your emissions system isn't working. It should be repaired so the car passes emissions and runs cleaner on cold starts.
What does switching valve A circuit malfunction mean in P0413?
It means the computer saw an electrical fault in the control circuit for the air switching valve 'A', usually a wiring, connector, relay, or valve problem rather than damage to the engine itself.