P0410AIR System A
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- After a cold start the secondary air (AIR) pump blows fresh air behind the exhaust valves so that unburnt fuel burns off and the catalyst heats up faster; a shut-off valve opens the path and stops exhaust from flowing back. P0410 is the general function code for secondary air system A. Many Bosch-managed engines check it passively: with the pump running, the front oxygen sensor must read lean or the fuel control must react; Pierburg lists P0410 as no lean signal, i.e. no air detected. Saab's Motronic 900, by contrast, uses it for too much air. GM's systems with a pressure sensor use P0411 and P2440 ff instead. The check runs once per trip after a cold start; driving is unaffected.
- What you may notice
- Check engine light on
- Secondary air readiness not set (emission test)
- Pump silent after a cold start, or unusually loud
- Driving normal, higher cold-start emissions
- Likely causes
- LikelySecondary air pump failed (water ingress, seized)
- LikelyCombination or shut-off valve carboned up or stuck
- PossibleVacuum hose or electric changeover valve leaking or faulty
- PossiblePump relay or fuse faulty
- PossibleAir ducts in the head carboned up or hose off
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €80 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.