Powertrain
generic / SAE
P2440
Secondary Air Injection System Switching Valve Stuck Open (Bank 1)
The switching/check valve in the secondary air injection plumbing on bank 1 is stuck in the open position. With the valve permanently open, exhaust gas can back-feed into the air pump and corrode it, while the downstream O2 sensor sees ambient air constantly.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / 40
Possible causes
- Switching valve stuck open by carbon or corrosion high
- Carbon or debris buildup preventing free movement low
- Component wear with age - mechanical play low
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 80–600 €
- Estimated time: 0.5–2.5 h
- Component: secondary air switching valve
- Component: secondary air pump
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012