P2444 on Subaru: How to Diagnose & Fix
Secondary Air Injection System Pump Stuck On (Bank 1)
1 Subaru model · 1 documented issue · 1 critical
P2444 on Subaru by model: symptoms, diagnosis and fix
On turbocharged Forester XT models, the relay controlling the secondary air injection (SAI) pump can fail in the closed position, leaving the air pump running continuously. Sustained operation can overheat the pump, which may melt and give off odor or smoke and possibly catch fire; the check engine light comes on when this happens. Subaru recalled about 100,000 turbo vehicles (Forester XT, Impreza WRX/STI, Legacy/Outback turbo) for the defect.
Common Symptoms
- Burning / melting smell from engine bay
- Air pump audibly running after engine warmed up or off
- Check engine light with SAI codes
- Blown SAI-circuit fuse
How to Fix
Free recall repair under Subaru campaign WTM-73 (NHTSA 16V-738): the dealer replaces the secondary air injection pump relay. If the pump itself was already damaged by prolonged overheating it is replaced as well. Owners of turbo XT models should confirm the recall has been completed by VIN, as completion rates on older vehicles are often incomplete.
Sources for this issue (4)
- NHTSA Part 573 Safety Recall Report 16V-738 (Subaru WTM-73)recall
- Subaru Product Campaign Bulletin WTM-73 — Secondary Air Injection Pump Relay Replacementrecall
- Subaru Recall WTM-73: Power Relay May Fail Allowing Air Pump to Overheat (NHTSA 16V738000)recall
- Subaru WRX/STI, Forester XT, Outback Recall for Fire Risk Reaches US Modelsarticle
P2444 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P2444 mean on a Subaru?
P2444 stands for "Secondary Air Injection System Pump Stuck On (Bank 1)." This powertrain/emissions code means the secondary air injection (AIR) pump for bank 1 appears to be stuck in the 'on' position, continuing to push air when it should be off. The secondary air system briefly pumps fresh air into the exhaust after a cold start to help the catalytic converter heat up and reduce emissions. The computer detected airflow or pressure when none was expected. This is mainly an emissions concern but, if ignored, can affect the air-fuel mixture and over time stress emissions components. On Subaru it is documented across 1 model: Forester.
What are the most common causes of P2444?
The most common causes of P2444 are: Faulty secondary air injection pump (running continuously), Stuck-open air switching/check valve, Wiring or relay fault keeping the pump powered, Faulty pump control relay, Connector corrosion or short in the AIR circuit, Faulty engine control module (rare). The specific cause varies by vehicle.
How much does it cost to fix P2444 on a Subaru?
Repair costs vary widely with the root cause and Subaru model; each issue on this page carries its own estimate where one is published.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.