P2440: AIR System Switching Valve Stuck Open Bank 1
What Does P2440 Mean?
P2440 is a diagnostic trouble code indicating: AIR System Switching Valve Stuck Open Bank 1. This code relates to the powertrain system. It has been reported in NHTSA complaints across 8 different vehicle models.
Symptoms of P2440
- ⚠️ Check engine light illuminated
- ⚠️ Loss of engine power
- ⚠️ Vehicle won't start
- ⚠️ Traction control system activated
- ⚠️ Vehicle enters limp/reduced power mode
- ⚠️ Failure to accelerate
Common Causes
- 🔍 Failed or deteriorated catalytic converter
- 🔍 Worn or fouled spark plugs
- 🔍 Clogged or leaking fuel injector
- 🔍 Turbocharger or boost system issue
- 🔍 EVAP system component failure
P2440 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"ON MY 2012 TACOMA THE CODE P2440 AND P2442 WHICH REPRESENT A STUCK OPEN VALVE IN THE SECONDARY AIR INJECTION SYSTEM. UPON MY RESEARCH INTO THIS ISSUE ON FORUMS I HAVE LEARNED THIS IS A COMMON PROBLEM WITH THE TOYOTA SYSTEMS PARTICULARLY THE 2012 TACOMA. THE COST OF THE PART IS ABOUT 400 TO 500 DOLLA"
— Toyota Tacoma owner, 04/10/2020
"FAILURE OF THE SECONDARY AIR INJECTION SYSTEM P2440 AND P2442, WHILE THE VEHICLE WAS MOVING ONTO A CITY STREET FROM A PARKING LOT. WHEN ACCELERATING IMMEDIATELY THERE WAS A DECREASE IN POWER AND THE CHECK ENGINE LIGHT ALONG WITH THE "TRAC OFF" LIGHT ILLUMINATING SIMULTANEOUSLY. THE VEHICLE HAS A NOW"
— Toyota Tacoma owner, 12/30/2019
"WHILE ON A ROAD TRIP I HAD MY CHECK ENGINE LIGHT COME ON WHILE ON THE HIGHWAY DUE TO DEFECTIVE SECONDARY INJECTION VALVES BEING STUCK CLOSED/OPEN. THE CODES I HAD FOR THIS ISSUE IS P2440 AND P2442. IN MY CASE THIS ISSUE MADE MY TRUCK GO INTO LIMP MODE WHICH IS OFTEN A LOSS OF POWER IN THE ENGINE AND"
— Toyota Tacoma owner, 04/25/2019
Source: NHTSA Complaints Database
Most Reported Vehicles for P2440
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | TOYOTA TACOMA | |
| 2 | TOYOTA TUNDRA | |
| 3 | SUBARU IMPREZA | |
| 4 | TOYOTA 4RUNNER | |
| 5 | TOYOTA SIENNA | |
| 6 | CHEVROLET CRUZE | |
| 7 | SUBARU FORESTER | |
| 8 | SUBARU WRX |
P2440 Reports by Vehicle
Detailed NHTSA complaint analysis for each vehicle model.
Diagnostic Tips
- Scan all modules, save freeze-frame data, and clear unrelated history codes before focusing on P2440.
- Confirm whether companion codes are present first; they often identify the root cause sooner than the headline DTC.
- Prioritize inspection around engine and the most common failure path for this code family.
- Graph upstream vs downstream O2 sensor activity at warm idle and cruise; downstream should stay more stable than upstream.
- After each repair step, complete one drive cycle and verify readiness monitors instead of judging success after a quick idle test.
- If the code keeps returning on high-incidence platforms (for example TOYOTA TACOMA), check TSB patterns and wiring/connector fitment before major part replacement.
Common Mistakes to Avoid
- ❌ Skipping freeze-frame review and losing the exact RPM/load conditions when the fault set.
- ❌ Installing a catalytic converter before ruling out upstream fueling/misfire conditions that can kill the new unit.
- ❌ Clearing P2440 and returning the car before monitors complete — this often creates repeat visits.
- ❌ Treating intermittent wiring or connector faults as permanent component failure without wiggle testing.
Frequently Asked Questions
Can I drive with this code?
Will this code clear itself?
How do I find the exact cause?
Reported Repair Costs for P2440
Based on 45 owner-reported repair costs from NHTSA complaints.
⚠️ These are owner-reported costs, not estimates. Actual costs vary by location, labor rates, and root cause. Source: NHTSA complaints database.
What To Do Next
Possible Fixes
- 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
- 🔧 Check and tighten the gas cap — replace if cracked or damaged ($5-15)
- 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
-
1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
-
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
-
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.