P0413
AIR System Switching Valve A Circuit Open
Secondary air injection (emissions)
Generic OBD-II
Medium
What it means
P0413 means the ECM has detected an open circuit in the secondary air injection system's 'A' switching valve. The secondary air system pumps air into the exhaust briefly after a cold start to help the catalyst light off and cut emissions. Because it only runs at cold start, the car drives normally — the fault mainly shows up as a failed emissions test.
Medium
Can I keep driving? Yes — the secondary air system only works briefly at cold start, so the car drives normally; the main effect is failing emissions.
Common symptoms
What you'll notice
- Check-engine light on
- Failed emissions test
- Little or no change in how the car drives
- Rarely, a brief rough idle during cold-start warm-up
Common causes
Most likely first
- Failed secondary air injection switching valve 'A'Likely
- Open or damaged wiring in the valve control circuitCommon
- Loose or corroded connector at the valveCommon
- Rarely, a faulty ECM driver for the circuitLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data, then inspect the switching valve connector and wiring for an open or corrosion.
- Check the circuit for the correct control signal and ground from the ECM.
- Test the switching valve's resistance and operation against spec.
- Repair the wiring or replace the valve as indicated, then clear the code and let the AIR monitor re-run.
FAQ
Quick answers
Is it safe to drive with P0413?+
Yes. The secondary air system runs only for a short time after a cold start to reduce emissions, so an open circuit here doesn't affect normal driving. It will, however, fail emissions.
Can I just clear P0413?+
It returns after the ECM re-checks the circuit unless the valve or its wiring is repaired.
Related codes
Often seen with P0413
Read & clear P0413 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX