P2440 Secondary air switching valve stuck open (bank 1)

Secondary Air Injection System Switching Valve Stuck Open Bank 1

Monitor

Most bulletins for this code describe only a check engine light, and KBB notes you can often drive with it, but have it checked early so it does not progress to drivability problems or catalytic converter damage.

It gets more serious if:

  • Inspect soon: Get it checked soon if the engine goes into limp mode (Toyota and Lexus describe limited throttle around 25 mph in sub-freezing weather), runs rough or stalls.

Source: how we rate severity

P2440 in short

P2440 means the engine computer thinks the secondary air switching valve on bank 1 is stuck open. On Toyota and Lexus trucks, water, ice or debris in the valve and engine computer logic in freezing weather are the usual causes. You can usually drive, but get it checked soon if the engine goes into limp mode.

On a cold start, some engines pump fresh air into the exhaust to heat the catalytic converter faster. An air pump supplies the air and a switching valve on each bank lets it in, then closes once the engine warms up.

P2440 sets when the computer sees signs that the bank 1 valve is still open when it should be shut. On Toyota systems, an air pressure sensor between the pump and valve should not see exhaust pulses when the valve is closed. On many Audi V6 and V8 models the valve is a vacuum-operated combi valve.

Toyota and Lexus link the code to ice or debris in the switching valve, moisture or a damaged filter in the air pump, and engine computer logic in sub-freezing weather. On some 2014–2016 Tundra and GX 460 trucks, the computer can also limit throttle to about 25 mph.

Most likely causes

  1. Air switching valve held open by water, ice or debris

    Supported by vehicle data
    Why it ranks here
    Toyota bulletins for 2012–2015 Tundra and Sequoia 3UR blame debris or ice in the air switching valve, Lexus modified the valve on the 2010–2013 GX 460, and Toyota's training case replaced the valves after a pump failure. On 2005–2009 4.7L models, Toyota lists P2440 among codes caused by contamination in the air system.
    What would change this
    Rises if the air pressure sensor still sees exhaust pulses with the valve commanded closed, or debris is found in the valve. Falls if the valve opens and closes cleanly in an active test.

  2. Engine computer logic that misreads the valve in freezing weather

    Supported by vehicle data
    Why it ranks here
    Toyota reprograms the engine computer for P2440/P2442 in freezing weather on 2012–2013 Tundra and Sequoia, and the 2014–2016 Tundra and GX 460 bulletins link the codes to sub-freezing temperatures. Volkswagen (2013–2015 Jetta, Beetle, Passat) and Audi (2019–2020 A3) also fixed false P2440 with software.
    What would change this
    Rises if the code only sets after cold nights and the dealer finds a newer calibration. Falls if the computer is up to date.

  3. Air pump damaged by moisture or a failed pump filter

    Supported by vehicle data
    Why it ranks here
    Toyota traced the codes on the 2012 Tacoma to moisture in the air pump and to pump filter damage, and Lexus modified the pump filter on the 2010–2013 GX 460. A damaged pump can send debris into the valves.
    What would change this
    Rises if the pump draws abnormal current, sounds rough or holds water. Falls if it runs normally in an active test.
    How to test the secondary air pump

  4. Vacuum solenoid or combi valve (Audi)

    Supported by vehicle data
    Why it ranks here
    Audi's bulletins for 2011–2015 models say either a combi valve on one bank or the vacuum solenoid that controls both is defective, and how the codes stored decides which part is replaced.
    What would change this
    Rises if P2440 and P2442 set together on an Audi, which points to the shared solenoid. Falls if only one bank sets, which points to that bank's combi valve.

  5. Valve wiring, hoses or air pressure sensor

    Possible — needs testing
    Why it ranks here
    Toyota's training case checks the valves for open and short circuits, and KBB lists wiring, hoses and check valves among the causes. No bulletin names these alone.
    What would change this
    Rises if a valve circuit tests open or shorted or a hose is split. Falls if the circuits and hoses test good.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all codes and freeze-frame data, and note whether P2442, P0418 or P2445 are stored too and whether the code set after a cold night.

    Low riskTool: OBD-II scan tool

    • IfP2440 and P2442 set together after freezing weather

      It meansToyota links this pattern to ice in the valves and computer logic.

      Go to step 2

    • IfOnly P2440 is stored

      It meansA single valve on that bank is more likely.

      Go to step 2

  2. Ask a dealer to check the VIN for engine computer updates and secondary air bulletins.

    Low riskTool: VIN lookup at a dealer

  3. With a scan tool that has secondary air active tests, run the pump and each valve with the engine running and watch the air pressure sensor and the upstream oxygen sensor.

    Use cautionTool: scan tool with active tests (for example Toyota Techstream)

    Warning:Run the engine outdoors or with exhaust extraction, keep hands clear of belts and the fan, and do not touch the air pump, valves or pipes: they get hot.

Symptoms

  • Check engine light on
  • Often sets after a cold or wet night
  • Limp mode with throttle limited to about 25 mph Gets more serious: stop and have it checked.
  • Rough running or stalling Gets more serious: stop and have it checked.

Compare with: Check engine light with loss of power

How to fix

  1. Ask a dealer to check the VIN for engine computer updates and secondary air bulletins first. Several fixes are a reprogram or updated parts.

  2. Note whether the code sets after cold or wet weather. This helps the shop choose between a valve fault and the software fix.

On your vehicle

Toyota

  • 2005–2016 · Tundra

    Supported by vehicle data

    2005–2006 4.7L: air system contamination. 2012–2015 5.7L: ice or debris in the air switching valve, engine computer update. 2014–2016 1UR-FE: limp mode possible in sub-freezing weather. Bulletin status not verified.

  • 2005–2015 · Sequoia

    Supported by vehicle data

    2005–2007 4.7L: air system contamination. 2012–2015 5.7L: ice or debris in the air switching valve and an engine computer update. Bulletin status not verified.

  • 2012 · Tacoma

    Supported by vehicle data

    1GR-FE: moisture in the air injection pump or a damaged pump filter. Bulletin status not verified.

  • 2005–2009 · 4Runner

    Supported by vehicle data

    4.7L 2UZ-FE: P2440 (bank 1 only) among air system codes caused by contamination. Bulletin status not verified.

  • T-SB-0079-16Status unverified

    MIL with P2440 or P2442, possible limp mode

    2014–2016tundra · issued · NHTSA 10134361

    1UR-FE trucks may enter limp mode (limited throttle, about 25 mph); triggered by sub-freezing temperatures.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0143-14Status unverified

    MIL with P2440 and P2442

    2012–2013tundra, sequoia · issued · NHTSA 10109359

    Debris or ice in the air switching valve; engine computer logic changed.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0144-14Status unverified

    MIL with P2440 and P2442

    2014–2015tundra, sequoia · issued · NHTSA 10109360

    Debris or ice in the air switching valve; engine computer logic changed.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0033-12 RevStatus unverified

    P2440/P2442 in freezing conditions

    2012–2013tundra, sequoia · issued · NHTSA 10133783

    Reprogram the engine computer.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0333-17Status unverified

    MIL with P2440/P2442, moisture in the air pump

    2012tacoma · issued · NHTSA 10140599

    Moisture intrusion into the air injection pump on the 1GR-FE.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0033-17 RevStatus unverified

    MIL with P2440, P2442 and P2445, pump filter damage

    2012tacoma · issued · NHTSA 10141580

    Air injection pump filter damage on the 1GR-FE.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • T-SB-0230-12 RevStatus unverified

    Secondary air injection codes on 2UZ-FE

    2005–20094runner, land-cruiser, sequoia, tundra · issued · NHTSA 10132097

    P2440 and other air system codes from contamination in the air system on 4.7L engines.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Lexus

  • 2010–2016 · GX

    Supported by vehicle data

    2010–2013: modified pump filter and air switching valve. 2014–2016: limp mode possible in sub-freezing weather. Bulletin status not verified.

  • L-SB-0038-16Status unverified

    MIL with P2440 or P2442, possible limp mode

    2014–2016gx460 · issued · NHTSA 10086315

    Same condition as the Tundra bulletin, triggered by sub-freezing temperatures.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • L-SB-0028-14Status unverified

    MIL with P0418, P2440, P2442 and/or P2445

    2010–2013gx460 · issued · NHTSA 10132729

    Air pump filter and air switching valve assembly modified.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Audi

  • 2011–2015

    Supported by vehicle data

    A6, A7, A8, Q5, Q7, S4, S5, SQ5: a combi valve on one bank or the vacuum solenoid that drives both. How the codes stored decides which. Bulletin status not verified.

  • A011519Status unverified

    MIL with P2440 and/or P2442

    2011–2014a6, a7, q5, q7, s4, s5 · issued · NHTSA 10119983

    One combi valve or the vacuum solenoid is defective.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • A011688Status unverified

    Replace combi valve or vacuum solenoid for P244000/P244200

    2011–2015a6, a7, a8, q5, q7, s4, s5, sq5 · issued · NHTSA 10130175

    Which part is replaced depends on how the codes were stored.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • A0119402058095Status unverified

    Software update for P244000

    2019–2020a3 · issued · NHTSA 10169522

    Engine computer software update for P2440 on the A3 Cabriolet.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

Volkswagen

  • 2013–2015 · Jetta

    Supported by vehicle data

    Also Beetle and Passat: engine computer software update for false P2440. Bulletin status not verified.

  • V011514Status unverified

    Update programming, P0491 and/or P2440

    2013–2015jetta, beetle, passat · issued · NHTSA 10122989

    Engine computer software causing false codes; update it.

    We couldn't confirm whether this bulletin is still current, so it doesn't count as confirmation.

  • P2442Secondary air switching valve stuck open (bank 2)

    Other bank Supported by vehicle data

    P2442 is the same fault on the other bank. When both set together, look for a shared cause such as ice, the air pump, software or, on Audi, the shared vacuum solenoid.

All Secondary air injection codes

P2440 questions

Is it safe to drive with P2440?

Usually, if the engine runs normally. Get it checked soon if it goes into limp mode, runs rough or stalls.

Why does this code come back every winter?

Toyota and Lexus link it to ice or moisture in the air switching valve or pump, and have released engine computer updates and modified parts for freezing conditions.

Sources and review

  1. P2440 code: AIR system switching valve stuck open bank 1 — Kelley Blue Book (KBB Service Advisor, reviewed by Gary Hardesty)
  2. MIL with P2440 and P2442 (bulletin T-SB-0143-14) — Toyota Motor Sales / NHTSA ,
  3. MIL with P2440 or P2442, possible limp mode (bulletin T-SB-0079-16) — Toyota Motor Sales / NHTSA ,
  4. MIL with P2440 or P2442, possible limp mode (bulletin L-SB-0038-16) — Toyota Motor Sales (Lexus) / NHTSA ,
  5. MIL with P2440 and P2442 (bulletin T-SB-0144-14) — Toyota Motor Sales / NHTSA ,
  6. MIL with P0418, P2440, P2442 and/or P2445 (bulletin L-SB-0028-14) — Toyota Motor Sales (Lexus) / NHTSA ,
  7. Toyota Secondary Air System Diagnosis and Repair (TOYOTAtech) — AutomotiveTechInfo.com / Toyota Motor Sales ,
  8. Secondary air injection codes on 2UZ-FE (bulletin T-SB-0230-12 Rev) — Toyota Motor Sales / NHTSA ,
  9. P2440/P2442 in freezing conditions (bulletin T-SB-0033-12 Rev) — Toyota Motor Sales / NHTSA ,
  10. Update programming, P0491 and/or P2440 (bulletin V011514) — Volkswagen of America / NHTSA ,
  11. Software update for P244000 (bulletin A0119402058095) — Audi of America / NHTSA ,
  12. MIL with P2440/P2442, moisture in air pump (bulletin T-SB-0333-17) — Toyota Motor Sales / NHTSA ,
  13. MIL with P2440, P2442 and P2445, pump filter damage (bulletin T-SB-0033-17 Rev) — Toyota Motor Sales / NHTSA ,
  14. MIL with P2440 and/or P2442 (bulletin A011519) — Audi of America / NHTSA ,
  15. Replace combi valve or vacuum solenoid for P244000/P244200 (bulletin A011688) — Audi of America / NHTSA ,
  16. Audi Air Injection Causes Trouble Codes — Vehicle Service Pros (TSB content from Mitchell 1) ,
  17. Final Regulation Order: 13 CCR §1968.2, Malfunction and Diagnostic System Requirements (OBD II), 2004 and subsequent model-year passenger cars, light-duty trucks and medium-duty vehicles (2015 amendments) — California Air Resources Board
Last reviewed
Written by
Saurabh K.
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