P2440 on Volkswagen
Secondary Air Injection System Switching Valve Stuck Open (Bank 1)
P2440 on Volkswagen vehicles indicates secondary air injection system switching valve stuck open (bank 1). Au7o has documented this code across 1 Volkswagen model — most commonly on Phaeton. P2440 indicates the secondary air injection (SAI) system's switching/diverter valve on engine bank 1 is stuck open. The secondary air system briefly pumps fresh air into the exhaust at cold start so the catalytic converter heats up and lights off faster, cutting cold-start emissions. The computer commands this valve closed once warm-up is done; if it senses the valve hasn't closed (air is still flowing when it shouldn't be), it sets this code. A stuck-open valve can let exhaust pressure or moisture back into the air pump and skews the oxygen sensor readings during warm-up. Typical repair costs on Volkswagen range from $300 to $1,200, depending on the specific model and root cause.
Common Causes of P2440
- •Air switching/diverter valve stuck open or seized
- •Carbon, rust, or debris fouling the valve
- •Faulty valve vacuum control solenoid or leaking vacuum line
- •Corroded or moisture-damaged secondary air pump
- •Wiring or connector faults at the valve solenoid
- •Clogged or failed combination/check valve
- •Vacuum leak preventing the valve from closing
P2440 on Volkswagen by Model
Volkswagen Phaeton(1 issue)
- Secondary Air Injection Pump Failure on V8/W12 (P0410/P2440)2004-2016
The petrol V8 and W12 engines have a secondary air injection (SAI) pump used during cold start to reduce emissions. Moisture (naturally present in exhaust) backflows through worn one-way check valves into the pump, corroding/freezing it and causing failure. This triggers a check-engine light with SAI codes. On the Phaeton the pump sits above the front of the left wheel-well liner. A frequent re-failure cause is not fitting the drain tube to the pump housing during replacement.
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View P2440 across all makes →Frequently Asked Questions
What does P2440 mean on Volkswagen?▼
P2440 stands for "Secondary Air Injection System Switching Valve Stuck Open (Bank 1)." P2440 indicates the secondary air injection (SAI) system's switching/diverter valve on engine bank 1 is stuck open. The secondary air system briefly pumps fresh air into the exhaust at cold start so the catalytic converter heats up and lights off faster, cutting cold-start emissions. The computer commands this valve closed once warm-up is done; if it senses the valve hasn't closed (air is still flowing when it shouldn't be), it sets this code. A stuck-open valve can let exhaust pressure or moisture back into the air pump and skews the oxygen sensor readings during warm-up. On Volkswagen specifically, this code is documented across 1 model.
What causes P2440 on Volkswagen vehicles?▼
Common causes on Volkswagen: Air switching/diverter valve stuck open or seized, Carbon, rust, or debris fouling the valve, Faulty valve vacuum control solenoid or leaking vacuum line, Corroded or moisture-damaged secondary air pump, Wiring or connector faults at the valve solenoid. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P2440 on a Volkswagen?▼
Repair costs on Volkswagen range from $300 to $1,200, depending on the specific model and root cause.
Which Volkswagen models have P2440 documented?▼
Au7o has documented P2440 on 1 Volkswagen model: Phaeton.