P2440: How to Diagnose & Fix — Secondary Air Injection System Switching Valve Stuck Open (Bank 1)
10 vehicles · 4 makes · $100-$4,000 repair
How to diagnose and fix P2440: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Toyota Tundra · 2005–2013
The secondary air injection pump is prone to failure due to water intrusion. The electric motor is located in the wheel well with moisture exposure, and the rubber boot covering the motor traps water, causing the pump to short circuit. This triggers check engine lights with codes P2440, P2443, P2445, P2447, P0418, or P0419. Some vehicles may enter limp mode.
Common Symptoms
- Check engine light illumination
- Jet engine noise on cold startup
- Decreased fuel economy
- Limp mode activation
- Rough idle when cold
How to Fix
Toyota extended warranty coverage on the air injection pumps and air switching valves for 2007-2010 models, and Warranty Enhancement Program ZG6 covers moisture-related air injection pump/switching valve failures on certain 2011 Tundras. Repair costs range from $2,000-$4,000 for OEM replacement. Some owners opt for aftermarket bypass kits with block-off plates.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 17610-0S010 genuine secondary-air pump assembly
replace the corresponding pump only when active testing and the applicable Toyota program identify it as failed Fitment/availability: Cataloged for selected 2007-2013 Tundra applications; exact engine, side/quantity, DTC branch, VIN and …
- Toyota 17610-0S030 genuine secondary-air pump assembly
replace the program-matched pump after active-test confirmation, with all required valves, inlets, gaskets and calibration handled separately Fitment/availability: Cataloged for selected 2012-2021 4.6L/5.7L applications; on this card use…
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Owner tips & cautions
- TipDIY repairs can save significantly - dealer charges $2,000-$4,000 but DIY costs are typically 50-70% less
- TipConsider OEM parts for critical components like sensors and electrical parts - aftermarket can be unreliable
- TipGet a proper diagnosis before replacing parts - similar symptoms can have different causes
Sources for this issue (2)
Toyota Sequoia · 2005–2009
The 4.7L 2UZ-FE's secondary air injection system fails due to corroded air switching valves (ASVs) and seized air pumps. Moisture enters the system and corrodes internal components. Causes check engine light with P2440/P2442 codes.
Common Symptoms
- Check engine light with P2440 or P2442 codes
- Rough idle on cold start
- Ticking or buzzing noise from air pump on startup
- Failed emissions testing
How to Fix
Replace air switching valves (Toyota 25710-50032 and 25710-50042, which supersede 25710-50030/25710-50040) and air injection pump (Toyota 17610-0C010) if seized. Many owners bypass the system entirely with block-off plates since it only operates during cold start for emissions. Bypass plates available from Trail Gear or fabricated from aluminum.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Toyota 17600-0F010 secondary air injection pump assembly
replace a debris-damaged secondary-air pump after bulletin diagnosis Fitment/availability: Exact pump listed by T-SB-0230-12 Rev1 for an eligible 2005-2007 Sequoia 2UZ-FE; replace only when bulletin inspection finds debris in the pump Fi…
- Toyota 25710-50022 air switching valve assembly
replace the corresponding failed or debris-damaged air switching valve Fitment/availability: Exact air switching valve assembly listed by T-SB-0230-12 Rev1; use only on the diagnosed valve branch and confirm VIN before ordering Fitment/a…
- Toyota 25720-50011 electric air control valve No. 1
1 valve only when its bulletin diagnostic branch confirms failure or damage Fitment/availability: Exact No. 1 valve listed by T-SB-0230-12 Rev1; not interchangeable with the No.
- Toyota 25720-50020 electric air control valve No. 2
2 valve only when its bulletin diagnostic branch confirms failure or damage Fitment/availability: Exact No. 2 valve listed by T-SB-0230-12 Rev1; not interchangeable with the No.
- Toyota 89580-34012 air injection control driver
replace the air-injection control driver on the bulletin's residual-code branch Fitment/availability: Exact driver identified by T-SB-0230-12 Rev1; use only if P0418 or P2445 remains after the applicable mechanical repair and confirmatio…
- Toyota 17171-50030 intake manifold-to-head gasket No. 1
reseal both intake-manifold-to-head joints during the applicable repair Fitment/availability: Exact gasket listed by T-SB-0230-12 Rev1; bulletin quantity is two when the applicable air-injection repair requires intake-manifold removal Fi…
- Toyota 17377-50010 air tube gasket No. 4
replace disturbed air-tube seals during the bulletin repair Fitment/availability: Exact air-tube gasket listed by T-SB-0230-12 Rev1; bulletin quantity is four for the applicable repair Fitment/availability: Ships in 1-3 business days wit…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Sources for this issue (2)
Lexus GX · 2003–2009
The secondary air injection (SAI) system pump and switching valves fail due to moisture intrusion and corrosion. The SAI pump introduces fresh air into the exhaust during cold starts to reduce emissions, but the pump motor corrodes internally and the switching valves stick. This triggers a check engine light with SAI-related codes.
Common Symptoms
- Check engine light with P2440/P2441/P2442 codes
- Rough idle on cold start
- Failed emissions inspection
- Whirring noise from passenger side of engine on cold start
How to Fix
Replace the secondary air injection pump and switching valves. Clean or replace the air injection check valves. Clear codes and verify operation. Some owners in non-emissions-testing states choose to bypass the system entirely with a tune.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- 17600-0F010 genuine Lexus secondary-air injection pumpOEM17600-0F010
Replace a commanded-test-confirmed failed secondary-air pump Fitment/availability: Live page explicitly fits 2004-2009 GX470 2UZ-FE/UZJ120. It does not verify the issue's 2003 year.
- 25710-50022 genuine Lexus secondary-air switching/diverter valveOEM25710-50022
Replace the diagnosed failed main air-switching/diverter valve Fitment/availability: Live page explicitly fits 2004-2009 GX470 2UZ-FE and supersedes 25710-50020/21.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipReplace both the pump AND the switching valves at the same time — if one has failed, the other is likely close behind. The valves are $150 each but save a second repair.
Toyota Sequoia · 2008–2019
Toyota Land Cruiser · 2008–2021
Find P2440 by make
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P2440 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 P2440 mean?
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.
What are the most common causes of P2440?
The most common causes of P2440 are: 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. The specific cause varies by vehicle.
How much does it cost to fix P2440?
Repair costs for P2440 range from $100 to $4,000, depending on the vehicle and root cause.
Which vehicles are affected by P2440?
Au7o has documented P2440 across 10 vehicle models from 4 manufacturers: Lexus, Subaru, Toyota, Volkswagen.
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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.