P0410 in 2026: Air Pump, Valve, Clogged Ports or Software — What 154 Documents and 559 Complaints Show

P0410 is the secondary air code, and the quick answer is "the air pump failed." The documents rarely say that.

P0410 is the general code for the secondary air injection system, and the maker papers almost never use it; they print narrower codes: Toyota prints P2440 as "Secondary Air Injection System Switching Valve Stuck Open Bank 1", GM prints P0411 as "Secondary Air Injection System Incorrect Air Flow Detected", and Audi prints P0491 as "Secondary Air System Insufficient Flow, Bank 1". The general-code label comes from standard code lists, not from a maker paper in our set. What the system does: 🟢 Toyota's dealer letters (the customer Q&A in them) say it "is designed to pump fresh air into the exhaust stream during a cold engine start; the fresh air helps speed the catalytic converter warm up time to reduce cold start emissions" (ZHA dealer package), and its F0A dealer letter says the system "operates briefly when a cold engine is first started" (F0A). It is an electric air pump, one or two switching (combination) valves, hoses or pipes and a relay; some cars add a pressure sensor.

Why a cold start. The pump runs only briefly after a cold start, so that is when a stuck valve, a failing pump or a blocked port shows, and when owners notice: "HEAR LOUD VACUUM CLEANER NOISE FROM PUMP WHEN STARTING COLD ENGINE, LASTS FOR ABOUT 30 SECONDS" wrote a 2006 Tundra owner. Toyota ties the valve fault to freezing weather: "This condition can be triggered by sub-freezing ambient temperatures" (T-SB-0079-16).

We went through NHTSA's index of manufacturer communications for papers that name a secondary air code or describe the system: 189 entries. Setting aside 3 with no file and 8 heavy-truck and bus papers, and counting exact copies once, leaves 154 distinct documents. Of the 186 entries with a file we read 88 in full (14 of them scanned pages) and compared 90 revisions and copies with them line by line. Of the 178 files we read or compared, only 2 print P0410, and they are two versions of one Bentley bulletin (TPI 2061064); 2 print P0411, 15 print P0418, 52 print P0491 or P0492, 47 print P2440 or P2442 and 16 print P2444 or P2445. No maker paper prints a repair for P0410 itself.

We also went through 559 complaints from NHTSA's file, received from January 2015 through September 2026, that name P0410 or a sister code (P0411 to P0419, P0491, P0492, P2430 to P2449) or describe the secondary air system in owners' words ("secondary air", "air injection pump", "smog pump"). Each was sorted twice, independently, by the same written rules; the two sortings matched on the main category in 92% of them (513 of 559). 483 describe a secondary air fault on the owner's car; 76 do not. Only 6 of the 483 print P0410 themselves, and 181 print some code of the family.

Where the complaints are. Toyota accounts for 393 of the 483 relevant complaints (Tacoma 183, of which 166 are model year 2012; Tundra 170, of which 83 are 2011-2012; Sequoia 25; 4Runner 13), Lexus 12, Subaru 25, Volkswagen 15, Chevrolet 15 and Audi 5. The file shows who wrote to NHTSA, not which cars fail: Toyota ran extended programs for this system and owners wrote about it. Toyota and Lexus papers are the only ones that print limp mode, so the power-loss shares below describe mostly trucks.

Claims marked 🟢 rest on a document listed in the Sources section. Every repair price on this page is what owners told NHTSA, published with ODI numbers. Every complaint count comes from the 559 complaints sorted twice and published; the documents file lists every index entry and how it was checked.

Words on this page. Secondary air injection (SAI): the system above. Switching valve, combination valve: the valve that lets the pump's air into the exhaust (Bank 1 and Bank 2 are the two sides of a V engine). ECM, PCM: the engine computer. DTC: a trouble code. MIL: the check engine light. Limp mode: reduced power and speed the computer chooses. Bulletin (TSB): a maker's repair instruction to dealers, not a recall. Campaign, warranty enhancement program: a free repair outside a safety recall; enhancements pay only for the listed condition. SSC, LSC: Toyota's Special and Limited Service Campaigns, free dealer repairs. Flash: a software update loaded into the computer. Software ID: the engine software's version number, on the label under the hood. 3UR, 1UR, 1GR, 2UZ-FE: Toyota engine names as the papers print them (3UR is the 5.7L V8, 2UZ-FE the 4.7L V8); LEA: the GM engine in the Equinox and Terrain bulletin. VIN: the 17-character vehicle identification number on your registration card. ODI number: NHTSA's reference number for a complaint.

I built PulsCar after a $380 "full diagnostic" in Phuket in 2025 led to roughly $6,000 over six months across several shops (the story is on the About page).

What P0410 says: a fault in the secondary air system, not in a named part

What the code reports. 🟢 Toyota's 2UZ-FE bulletin lists the codes behind its warning light as "Switching Valve “A” Circuit", "Relay “A” Circuit" and "Pump Stuck Off Bank 1" and says the condition "may be caused by debris passing through the air injection pump assembly and contaminating various components in the system" (T-SB-0230-12 Rev1). Audi blames carbon, a vacuum leak, a combination valve or software depending on the engine.

What you feel. Sometimes a check engine light and nothing else. On the Toyota and Lexus trucks that dominate the file it is more: 🟢 Toyota's campaign letter says the vehicle could enter limp mode, in which "the vehicle's power and speed will be reduced, which could inconvenience you and require immediate repair" (F0A owner letter). Of the 483 relevant complaints, 300 describe a stall, a loss of power, a limp mode or a speed cap, or a traction light on with the engine light (292 of them on a Toyota or a Lexus).

What it is not. It is not the converter efficiency code (P0420, P0421), a lean code (P0171) or a misfire (P0300), although a car in limp mode can feel rough.

What is P0410, and is it usually the air pump, the valve or a clogged port? PulsCar went through 154 distinct maker documents and 559 federal complaints on the secondary air system, each complaint sorted twice by fixed rules. Only 6 of the 483 relevant complaints print P0410, and only two documents, versions of one Bentley bulletin, do; owners and maker papers use P2440, P2442, P2445, P0418, P0491 or P0411 instead. Where a shop or dealer named or replaced a part, the owner names a pump in 73 cases, a valve in 62 and several parts together in 123, and 199 report no shop diagnosis or repair. The papers are less part-focused: a software update, a relay, a vacuum leak, carbon in the ports, moisture and ice come first in several makers' instructions, and Toyota's 20TC01 says not to replace the pump unless a pump code is set. These are complaints, not failure rates. Read the exact code, then test the cheap causes first.

First: P0410, P0411, P2440/P2442, P2444/P2445, P0418, P0491/P0492 ... which one is yours

Read the exact code before you buy anything. The family has more than 30 members; the papers treat it as one system, so this page does too.

Which code you will probably see. On a Toyota, Lexus or Subaru most likely P2440 or P2442, with or without P2445 or P0418; on an Audi or Volkswagen P0491 and P0492 together (V6) or P244000 (3.0T, A3; Audi prints two extra digits, and P244000 is P2440); on a GM Equinox or Terrain P0411. In the complaints: P2442 in 97, P2440 in 79, P2441 in 16, P0418 in 16, P2445 in 10, P0411 in 9, P0410 in 6, P0491 in 5.

The labels differ by maker. 🟢 Audi writes "DTC P244000 (Secondary Air Injection System Switching Valve Stuck Open Bank1)" (2058095/1); Toyota's 4.7L bulletin lists "P2445 - Secondary Air Injection System Pump Stuck Off Bank 1" and then names P2445 "Pump Stuck On" in a repair-manual title for the 2006-2009 4Runner (T-SB-0230-12 Rev1); Bentley maps "Bank 1 Pressure check P0410" (TPI 2061064). A scanner label tells you the circuit; the paper for your car tells you what the maker found.

The maker atlas: who prints software, a relay, a vacuum line, carbon ports, a valve or a pump

The documents split by maker: a 2012 Tundra in freezing weather and a 2011 Audi with carbon in its cylinder head are on different roads. Document numbers link to the NHTSA PDF. (Honda's 20-061 is a fuel-cell air pump controller, a different system.)

The Toyota papers argue with each other, and that is the finding. 🟢 The same warning light has four printed causes: debris or ice in the switching valve, fixed by software (F0A, T-SB-0144-14); software that may "cause an emissions control component called an Air Injection Pump to fail under certain driving conditions" (D0E); moisture or water in the pumps and valves (POL11-05, ZG6, ZHA, ZLH); and a moisture-degraded pump filter (JLG, 20TC01). The 2012 Tacoma bulletin changed its own cause in five months: "This condition may be caused by moisture intrusion into the air injection pump." (T-SB-0333-17), then "This condition may be caused by air injection pump filter damage." (Rev1). Lexus' bulletin changed its repair logic: Rev1 replaces by code ("If DTC P2440 is present, replace the Secondary Air Injection Valve Assembly (Bank 1) and Secondary Air Injection Pump", Rev1); Rev2 says "If one or more of the above DTCs are present, replace all parts listed in procedures below." (Rev2).

The do-not-replace lines: what the papers tell a shop not to buy first

Papers that say do not buy the part first. 🟢 Toyota, Tacoma 2012: "DO NOT replace the air pump unless these DTC’s are present." (20TC01). 🟢 Toyota, software papers: "The ECM (PCM) should NOT be replaced as part of the Repair Procedure." (T-SB-0079-16); F0A: "Replacement parts are not required for this SSC." (F0A). 🟢 Volkswagen: "DO NOT diagnose or replace Combination Valve, Secondary Air Pump, Secondary Air Hose, before performing the update function as explained in this bulletin." (2040822). 🟢 Subaru: "Replacement of the air pump is only required if the Check Engine light is illuminated and the corresponding DTC is present." (WTM-73R). 🟢 Toyota, 4.7L: valves are "Replace ONLY If damaged by debris. Reuse parts when possible." (T-SB-0230-12), and POL11-05 says of the 2UZ-FE "Most vehicles will not require the replacement of the Bank 1 Air Pump." (POL11-05). 🟢 Audi: the 2033001 pump rule changed in revision 9 (October 13, 2016) from replacing the pump to saying the bulletin does not apply, and the A8 paper puts a vacuum test before any valve (2033001/26, 2035002/4). 🟢 GM: "If moisture/ice has been confirmed to be the cause ... do not proceed with the bulletin." (18-NA-061).

Papers that say replace the parts together, or the pump outright. 🟢 Toyota's 2012 Tacoma Rev1: "ALL parts listed in this bulletin MUST be replaced to ensure the condition is properly addressed" (T-SB-0333-17 Rev1); POL11-05 for the 1GR, 1UR and 3UR engines, if moisture or water is found: "it is imperative that all air pumps and the emission control valves are replaced."; Audi's S6 and S7 paper: "Replace the secondary air pump motor (V101) and update the ECM software." (2036558/3). The difference is the evidence asked for first: Rev1 drops the voltage and pressure tests of its original issue, while 20TC01 for the same truck says the pump is only for a pump code.

The 10-minute check

Everything here is our advice, built from what the papers test first; it needs only a code reader and your ears.

1. Write down what happened. A cold morning, freezing weather, a noise for the first seconds, a truck that would not go faster than 35 mph, a trip to the mountains: the papers split on exactly this.
2. Read the whole list of codes. On the Audi 3.0T the shop's paper checks which stored code turned the light on: one code points to a combination valve, both codes together (stored at the same time) to the vacuum solenoid; on a Subaru STI one switching-valve code means checking both banks.
3. Listen at a cold start. The pump should run briefly and stop. A loud noise that lasts, or a pump that keeps running after the engine is off (the recall's printed symptom is a pump that may operate continuously, with the check engine light on), is a reason to stop, switch off and call a tow, then the dealer.
4. With the engine off and cool, look. Hoses on at both ends, not split or taped.
5. Ask the dealer by VIN. "Does this VIN have an open recall, campaign or software update for the secondary air system?" is the first question of every route below.

Six secondary air situations, and which is yours

1. A steady light, the car drives normally (Routes 1 and 5). Reset once, drive, ask about software and the programs before parts. The exception is a Subaru turbo under recall 16V738: do not reset and drive on; contact a Subaru dealer immediately.

2. Check engine and traction lights, then a truck that crawls (Routes 1, 4 and 5). Software if the code is P2440 or P2442 on a 3UR or 1UR truck; a pump or valve if P0418, P2444 or P2445. This is the limp-mode case; see "Can you drive".

3. A loud whine or vacuum noise for seconds at start-up, then a light (Route 5). Some owners with a failed pump describe exactly this; the first question is whether a program covers your VIN.

4. Smoke, or a pump that does not stop (Route 2, Subaru). Pull over, switch off, do not drive it and call a tow, then the dealer for the recall (towing is free); the letter highly recommends not parking in a garage.

5. P0491 and P0492 together on an Audi or Volkswagen V6, or P0411 on a GM LEA engine (Route 3). Carbon in the ports (Audi and VW papers) or moisture and deposits in them (GM) are the printed causes; but on a Q7 3.0T the bulletin for the same pair (2039899) names water in the pump after deep-water driving and says to check that the pump runs before replacing it.

6. The light is back after a pump or valve was replaced (Routes 2 and 4). In the file, 56 of 483 complaints say a light, code or symptom returned or a repair did not hold. The papers give reasons: a relay left in place when the pump was replaced, a cause on the other bank, and parts replaced one bank at a time (Lexus' first revision) against all at once (its second).

The secondary air price ladder, from the bottom up

No repair guide on this site prices a secondary air pump or valve, so there are no ⚪ estimates here: the dollar rows are what owners told NHTSA, the others what the papers print.

The ladder is a rule of thumb for order, not a forecast: 115 of the 149 dollar figures in the file are quotes or amounts the narrative does not say were paid, billed or offered. A whole-system median below the pump-alone median does not mean valves add nothing: the figures come from different owners, and most are quotes or unstated amounts.

The five secondary air routes, cheapest first

Owner counts come from the 483 relevant complaints; "came back" means the owner says the same light, code or symptom returned or the repair did not hold. 405 of the 483 drive a Toyota or a Lexus, so none of these shares is a forecast for your car.

Route 1 · Software, a cold reset and altitude — $0 to ask

What it is. The computer logic, not a part, is the printed cause: a routine that does not clear ice or debris, software that can make a pump fail, a diagnostic that reports faults that are not there.

What the documents say. 🟢 Toyota and Lexus: 2014-2016 Tundra and GX 460 with the 1UR-FE may set P2440 or P2442 and "may enter limp mode" with a throttle limit of about 25 mph; "This condition can be triggered by sub-freezing ambient temperatures." The fix is a flash, because "The ECM (PCM) should NOT be replaced as part of the Repair Procedure." (L-SB-0038-16). The 2012-2013 3UR trucks get the same flash for "debris/ice in the air switching valve assembly" (T-SB-0143-14). Campaign F0A reaches certain 2012-2014 Tundra and Sequoia: "The current Air Injection System Control Logic may not clear itself of debris/ice that may become lodged at the air switching valve." and "Replacement parts are not required for this SSC."; Toyota "has turned Limited Service Campaign (LSC) F0A into Special Service Campaign (SSC) F0A with no expiration date" (F0A). D0E (completing it also completes F0A) replaces the Bank 1 pump only with old software and P0418 or P2445: "If the ECM has the updated calibration and P0418 and/or P2445 it is not covered under this campaign." (D0E). 🟢 Volkswagen: for P0491 or P2440 on certain 2013-2015 Jetta and Beetle and 2014-2015 Passat the cause is "Current ECM software causing erroneous faults." (2040822); for the 2022 Golf GTI, "The error detection of a stuck open secondary air valve is deficient above an altitude of 6560 ft. (2000m)." and "Volkswagen is not notifying consumers." (24iM, dealer notice). Audi's A3 with P244000 gets software too (2058095/1).

What the owners report. None of the 483 complaints ends at a software update as the only repair. Of the 199 with no shop or dealer diagnosis or repair, 128 report a stall, a loss of power, a limp mode, a speed cap, or a traction light on with the engine light. A 2012 Tacoma owner wrote that the codes "PUT ME INTO LIMP MODE WHILE ON THE FREEWAY IN SNOWY AND ICY CONDITIONS"; a 2011 Tundra owner described a drop "from 70 mph to 40 mph". Another 2012 Tacoma owner, with P2440 and P2442, was told by the dealer "THE ECM COMPUTER IS BAD"; Toyota's software papers for other trucks print the opposite.

The cheap cause that gets skipped. Software that is not the latest. Toyota's bulletins tell the dealer to check the label: "If the calibration ID listed is the latest ECM (PCM) calibration – this bulletin does NOT apply. Continue diagnosis using the applicable Repair Manual." (T-SB-0143-14).

Fix it yourself. Only look; do not flash the software yourself (our advice): the papers require a battery support station to hold 13.5 volts during a flash and a label on the car afterwards. No limp mode, and not a Subaru turbo under recall 16V738? Clear the code once with a reader, drive, and see whether it comes back.

At the shop — say this: "Is there a software update or a campaign for the secondary air system on my VIN? Please check the software version on the label under the hood before you order a pump or a valve, and tell me the number."

Route 2 · The relay, the vacuum lines and the hoses — free under the Subaru recall

What it is. The pump or the valve is fine and the thing that feeds or controls it is not: a relay welded closed, a vacuum line that is off, a split pipe, a taped hose, a pressure sensor.

What the documents say. 🟢 Subaru recall 16V738 (100,127 vehicles): "the relay may allow the pump to operate continuously" and "the secondary air injection pump could begin to smoke, increasing the risk of fire". Subaru replaces the relay free and the pump only "if the Check Engine light is illuminated and the corresponding DTC is present"; "If replacing the air pump is required, do not start the car until the relay has been replaced." (WTM-73R). Audi's 3.0T paper gives two causes for P2440 and P2442, a defective combi valve or "The vacuum solenoid is defective.", and says "Before performing any repair, determine if Scenario A or Scenario B is causing the condition." (2040403/1). Aston Martin (DB11 V12, P0492 only): "In some incidents, the pipe has split at the elbow for the sensor." (SB-03-0450). Subaru's STI paper: "there is a possibility the root cause may be related to component(s) found on the opposite bank of the engine for the displayed DTC." (11-147-14). The A8 4.2 paper checks the vacuum check valve, then applies vacuum to the lines with a hand pump, 400 mmHg (2035002/4), the R8 paper replaces a pressure sensor (2049142/2), and BMW's service action is a coolant hose rubbing the secondary air check valve gasket (SIB 17 01 00).

What the owners report. Of the 25 Subaru complaints, 13 mention the recall and 9 are among the 10 smoke or fire reports. Across the file 6 complaints end at a relay, wire or sensor, and 4 of the 6 say it came back. Almost no owner prices this group: the one hose-and-sensor repair in the file was $350 (a 2009 Jetta). The file's five "other part" figures, which also include a bypass kit and two port cleanings, run $350 to $2,500. A 2009 WRX owner wrote that after the recall relay the dealer "INFORMED ME THAT I WOULD HAVE TO PAY FOR THEM TO CHECK THE PUMP"; a 2014 Impreza owner wrote that the dealer "did not replace relay alongside the pump" and the relay then failed.

The cheap cause that gets skipped. The part upstream of the one the code names: on a Subaru turbo the relay, on an Audi 3.0T the solenoid before the valves, on an STI the other bank.

Fix it yourself. Only the looking: hoses on at both ends, nothing split or taped (our advice). Under the Subaru recall the repair and the towing are free, so there is nothing to save by doing it at home; a pump that keeps running after the engine is off is a stop-and-tow, not a project.

At the shop — say this: "Is the pump relay replaced under recall 16V738, were the vacuum lines tested, and was the other bank checked? If a pump is quoted, was the relay replaced first?"

Route 3 · Clogged ports: carbon, deposits and moisture — a pressure wash, not a part ($500 and $2,500 in two owner reports)

What it is. The pump runs and the valves move, but the air cannot get into the exhaust: carbon or deposits in the small ports of the cylinder head, or ice and moisture in the lines.

What the documents say. 🟢 Audi (3.2 FSI and 3.0 TFSI V6), P0491 and P0492 stored together with more than 15,000 miles: "Under certain driving conditions, the secondary air ports in the cylinder head can accumulate carbon over time, causing a restriction." After a test, the repair is a pressure wash of the ports with the converter pipes lowered, the plugs and a coolant pipe removed and a new freeze plug (2033001/2, 2033001/8). The pump comes first: for the 3.2 FSI A6 and the Q7 3.0T, revisions 7 and 8 (2014-2016) say "If the pump is not running or if it makes abnormal/unusual noise, replace the secondary air pump."; for the other models they ask the technician to check that the pump runs normally. The later revisions say that if the pump does not run or is noisy the bulletin does not apply (2033001/26). A sister paper covers a service-reset message with the light off: "clean immediately" or "clean within next 1000 miles" (2035454/4). VW's Touareg Hybrid paper uses the same test (2040202). 🟢 GM, P0411 on 2013-2015 Equinox and Terrain with the LEA engine: "This condition may be caused by moisture and/or ice build up in cold climate areas." and "This condition may also be caused by a by-product of using inferior fuel, creating restriction in the SAI ports in the cylinder head"; if moisture or ice is confirmed "do not proceed with the bulletin" (18-NA-061).

What the owners report. 13 complaints end at a hose, a port or a line; 4 of them say it came back. A 2016 Q5 owner was billed $249 for the diagnosis and quoted $2,500 for cleaning the cylinder-head ports; a 2015 Terrain owner had "Water in PCV system obstruction in the secondary air system" cleaned for $500.

The cheap cause that gets skipped. The test that decides between a port and a pump. Audi's early test read two values from the secondary air system check before anything was taken apart: a pressure difference above 170 mbar with an air-flow value below 0.6 meant the ports had to be cleaned; GM asks for a moisture and ice check, with a thaw, before it cleans ports.

Fix it yourself. No. The wash needs the coolant drained, the converter pipes lowered and a special tool set (our reading of the steps). A light that appears only in freezing weather deserves the moisture question before a teardown.

At the shop — say this: "What were the measured flow values before and after, did the pump run and sound normal, and was moisture or ice ruled out? Please write the readings on the invoice."

Route 4 · The switching (combination) valve — $400 to $2,860 in owner reports

What it is. The valve that opens the pump's air to the exhaust is stuck open, stuck closed or leaking, or its check valve has failed.

What the documents say. 🟢 Toyota's 2012 Tacoma bulletin first set tests (a voltage check with the pump on and a pressure reading while it ran) and replaced pump, cover, valve and gaskets only when liquid was found; its revision dropped the tests and replaces all four on any of three codes (T-SB-0333-17, Rev1). Lexus' GX 460 paper replaced a valve by code (P2440 valve and pump, bank 1) and in Rev2 replaces "all parts" (Rev1, Rev2). Smart: "The secondary air injection system combination valve may not close completely under certain climate conditions due to condensation in the exhaust system.", warranty "from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 15 years / 150,000 miles" (11031591).

What the owners report. 62 complaints end at a valve, and 16 of them (26%) say it came back, the highest share among pump, valve and whole-system complaints (pump 11 of 73, several parts or the whole system 12 of 123; the small relay and hose groups come back more often, 4 of 6 and 4 of 13). 25 owners give a valve figure: median $1,300, from $400 to $2,860. A 2008 Tundra owner: valve "FAILED FOR THE 2ND TIME UPON STARTUP", free the first time at 68,000 miles, "COST IS $2100 FROM THE DEALER!" at 154,000; a 2010 Impala owner paid $567 and then $478 for the same check and shut-off valve.

The cheap cause that gets skipped. The other bank and the second valve. Subaru's STI paper says the cause may be on the opposite bank, and Lexus moved from one bank's valve plus the pump (Rev1) to all parts (Rev2).

Fix it yourself. The papers give an owner no steps. Three Tacoma owners wrote that they did the job themselves or took the system apart (parts $770 in one, about $1,000 in total in another, new valves for $479 in a third); we do not rate it a home job, because Toyota's revised paper says "ALL parts listed in this bulletin MUST be replaced" (Rev1), and the gaskets and cover are part of the repair (our reading).

At the shop — say this: "Which code lit the light, one bank or both? Was the other valve and the pump inspected for liquid or damage? If you replace a valve, are the cover and the gasket included, and is my VIN in a program that pays?"

Route 5 · The air pump and the whole system — $500 to $5,000 in owner reports

What it is. The pump itself has failed (a filter that let moisture in, debris, a bearing, water) or the whole assembly is being replaced under a moisture program.

What the documents say. 🟢 Toyota's 2UZ-FE paper: "This condition may be caused by debris passing through the air injection pump assembly and contaminating various components in the system", and "The debris may consist of air injection pump filter material or fan blade fragments." (T-SB-0230-12 Rev1). The moisture programs replace pump and valves: ZG6 (2011 Tundra and Sequoia), ZHA (2012 Tacoma) and ZLH (2010-2013 GX 460) say "moisture/water in the Air Injection Pumps and/or Air Switching Valves" (ZG6, ZHA, ZLH), and campaign JLG replaces the pump filter and the switching valves free because "There is a possibility that moisture in the air may cause a filter in the vehicle emissions system to degrade." (JLG). 20TC01 for the 2012 Tacoma installs a repair kit unless a pump code is set: "Air Pump Assembly replacement is only necessary if DTC’s P2444, P2445 and/or P0418 are present." (20TC01).

What the owners report. 73 complaints end at a pump and 123 at several parts or the whole system; 11 and 12 of them say it came back. Pump owners give 29 figures (median $2,200, $500 to $5,000) and whole-system owners 86 (median $2,058, $750 to $4,200). A 2012 Tacoma owner at 91,000 miles got code P2445 and listed the dealer's bill as valve $690, pump $813, gaskets $132 and labor $610 under "TOTAL $2063"; those four lines add to $2,245, and both numbers are the owner's. For the Tundra owner's view by mileage see Toyota Tundra problems by mileage.

The cheap cause that gets skipped. The program that already pays. 209 of the 483 complaints mention a recall, campaign, extension or bulletin for their car as performed, offered, missing, refused or asked about, and most programs have an end date, a mileage line or a first-use date that the dealer reads from the VIN; a few print none.

Fix it yourself. No: some papers replace pump and valves together once their conditions are met (our reading), while 20TC01 wants a pump code for a pump and the 4.7L paper reuses sound valves; either way it is a shop job (our advice).

At the shop — say this: "Which codes are stored, P2444, P2445 or P0418? Is my VIN in ZG6, ZHA, ZLH, POL11-05, JLG or 20TC01, and was the filter or cover damaged and was there liquid in the pump?"

The coverage file: which programs and recalls run in September 2026

Status "as of September 2026" is our computation from the printed terms; "cannot be computed" means the paper prints no end date or no start point. A recall or a program is not a repair of your car until a dealer has done it and written it down; ask by VIN.

Toyota's programs are narrower than the trucks that fail. 🟢 ZG6 covers "Certain 2011" Tundra and Sequoia, ZHA the 2012 Tacoma and ZLH the 2010-2013 GX 460; a 2012 Tundra, a 2005-2006 Tundra and a 2014 Tacoma are in none of the moisture programs listed above. The 2012 Tundra owner who paid $3,034.87 wrote that the parts matched "POL17-02 WHICH COVERS THIS DEFECT IN OTHER MODELS, BUT NOT IN MY 2012 MODEL". For the 2012 Tacoma, 131 of the 166 complaints were received before ZHA was announced on January 11, 2018. The software papers' own emission warranty is 96 months or 80,000 miles from the in-service date, which has run out by time for cars put in service before September 2018.

The documents contradict each other on one number. 🟢 The ZHA policy bulletin prints a California Emission Warranty of "3 years or 50,000 miles" (POL18-01); the ZHA dealer package prints "7 years or 70,000 miles" (ZHA package). Ask which one the dealer applied.

F0A's end is a question, not an answer. The April 2016 package says the program is "extended with no expiration date", and nothing we read shows whether it is still open in September 2026; the label under the hood shows whether the software was already updated.

What 559 complaints show

How we went through them. We took every complaint in NHTSA's file received from January 2015 through September 2026 that names P0410 or a sister code, or describes the secondary air system in owners' words and says something went wrong. Each was sorted twice by the same written rules and the two sortings matched on the category in 92% of them (513 of 559); a written rule settled every disagreement. We publish the sorting rules and how we did it.

300 describe a stall, a loss of power, a limp mode or a speed cap, or a traction light on with the engine light (62%), 292 of them on a Toyota or a Lexus; 209 mention a recall, bulletin, extension or campaign; 56 say the same light, code or symptom returned or the repair did not hold; 10 describe smoke, a burning smell, heat damage or fire. NHTSA's own fields record 1 crash, 6 fires and 3 tows, and no injury or death. The cars run from model year 1994 to 2022 with a median of 2012, and the 394 that give a mileage have a median of 78,000. Where the complaint ends at a valve, 16 of 62 owners say the problem returned; at a pump, 11 of 73; at several parts or the whole system, 12 of 123; where it ends with nothing diagnosed, 7 of 199.

Can a failed secondary air pump or valve put a truck in limp mode, and does replacing the part end it? PulsCar sorted, twice and independently, the 559 NHTSA complaints from 2015 to September 2026 that name a secondary air code or describe the system: 483 describe a fault on the owner's car, 300 of them a stall, a loss of power, a limp mode, a speed cap or a traction light with the engine light, 292 of those on a Toyota or a Lexus. Where the complaint ends at a valve, 16 of 62 owners say the problem returned; at a pump, 11 of 73; at several parts or the whole system, 12 of 123. Toyota's own letters print that limp mode reduces power and speed and may require immediate repair, and Toyota prints its fixes as measures that reduce the possibility, not remove it. These are complaints, not failure rates. Our rule: limp mode on a highway means stop safely and tow, not drive on.

The 6 complaints that print P0410, and what they show

The 6 complaints that print P0410: three are Subaru (a 2009 Forester, a 2013 Impreza and a 2014 Impreza), and one each Ford, GMC and Mercedes-Benz; 1 ends at a valve, 1 at the whole air system (diagnosed, not repaired) and 4 with nothing diagnosed. A 2009 Forester owner wrote that the pump "ACCUMULATES MOISTURE" with codes "P2444, P2444B, P0410, P2440" and "UPTO $1500" to fix. A 2004 Envoy owner wrote "OBD II CODE P0410 SECONDARY AIR INJECTION VALVE CHECK VALVE" replaced twice, and a 2013 Impreza owner that two codes "restricted me from passing safety inspection".

The 10 complaints with smoke, burning or fire

Ten complaints describe smoke, a burning smell, heat damage or fire, and 9 of them are Subaru cars of model years 2006 to 2017 (the recall covers only turbo models; most owners do not name the engine); the tenth is a 2005 Tundra owner whose pump fan "BROKE AND THE PIECES BLEW INTO THE EXHAUST PORTS AND MELT". A 2008 WRX owner, parked with the engine off, was told of smoke, found the plastic pump on fire under the hood and put it out with an extinguisher; a 2008 Forester owner's pump "CAUGHT FIRE" while driving and "BURNED OUT ON ITS OWN"; a 2009 Impreza was "ENGULFED IN FLAMES" on a highway shoulder 29 days after the recall relay was replaced; a 2017 WRX owner wrote "Car engulfed in flames" ten days after the dealer repaired the air system a second time; a 2013 Impreza owner, writing in July 2024, shut the engine off and found the pump "kept running" and hot. At least four of the nine are model years that the recall's printed list does not include (a 2006 WRX, a 2008 Forester, a 2016 WRX and a 2017 WRX), and we cannot tell whether the relay or the pump started any of these. What the paper prints is clear: 🟢 "do not operate the vehicle" if you smell smoke, a precautionary "highly recommended" not to park in a garage, car port or other structure until repaired, and "Both the repairs and the towing will be at no cost to you." (WTM-73R). Any car with a hot-plastic smell from under the hood gets the same answer from us: stop, switch off, call a tow.

What owners say they paid

Of the 483 relevant complaints, 135 state a dollar figure that meets our inclusion rule, 149 figures in all (one text filed three times counts once): 15 amounts paid, 18 bills, 72 quotes, 43 where the narrative does not say and 1 offer. The figures are what owners wrote, not audited invoices, and we publish them with ODI numbers.

The 140 repair figures (whole system, pump and valve) have a median of $2,000, from $400 to $5,000; amounts paid (12 of the 15) have a median of $1,335 and bills (15 of the 18) $2,063. 131 of the 140 are Toyotas, 5 Lexus, 2 Subaru and 2 Chevrolet. Details: the 2012 Tacoma bill that does not add up (Route 5; ODI 10943863); a 2009 Q5 owner who paid $2,045.75 for repairs at an Audi dealer after a 2019 warning light.

How much does it cost to fix a secondary air fault, and who pays? PulsCar's reading of the file: nothing for a software update or a Subaru recall relay when covered; owners who gave a figure for a pump, the valves or the whole system name a median of $2,000 (140 figures, $400 to $5,000), a valve alone $1,300 (25 figures), a pump alone $2,200 (29). Of the 149 figures in the file, 15 are amounts owners say they paid and 18 are bills; 72 are quotes and 43 do not say. A 2012 Tacoma owner listed valve $690, pump $813, gaskets $132 and labor $610, which add to $2,245, not the $2,063 total they wrote. No repair guide of ours prices a secondary air pump, so these are single owner reports, not a price list. The ranking is the useful part: ask for software, a program and the relay before a pump.

Why a secondary air code comes back after a repair

The remedy reduces, it does not remove. 🟢 Toyota's F0A letter says the software "has been updated to reduce the possibility of this condition occurring" (F0A), and its Tacoma bulletin says "Air pump cover installation will reduce the possibility of filter damage." (T-SB-0333-17 Rev1). The part was not the whole story. Lexus' first revision replaced one bank's valve and the pump, its second everything; Subaru's STI paper says the cause may be on the other bank. The moisture is still there. JLG and 20TC01 blame moisture degrading a filter. The recall fixes the relay, not a pump already damaged. One owner writes that the dealer charged for the pump check after the recall relay, and a 2014 Tacoma owner whose pump was "replaced twice already" wrote of a valve code on a "6 month old part"; a 2014 Impreza owner had the pump fail twice in 13,057 miles.

Can you drive with a secondary air code?

It depends on how the car behaves, and this is our rule, not any maker's. A steady light with normal driving and no stalls: a shop within days (a Subaru turbo under recall 16V738: contact a Subaru dealer at once if the light is on). If the car has stalled, lost power, shown reduced power or limp mode, failed to restart even once, or the check engine light is flashing, pull over safely, switch the engine off and have it towed; the one exception is a shop within 2 to 3 miles, reached gently, under 40 mph and on a light throttle. What the papers print: 🟢 Toyota's campaign letter says that in limp mode "the vehicle's power and speed will be reduced, which could inconvenience you and require immediate repair" (F0A owner letter). For limp mode no document we read says to stop driving or tow. On a highway in limp mode, move to the shoulder or off the road safely and stop; do not keep driving. Only if a restart then brings full power back and the shop is within 2 to 3 miles, go gently under 40 mph; otherwise tow. A hot-plastic smell, smoke or a pump that runs with the engine off is a stop-now case on any car, and on a Subaru turbo it is a recall case.

Should you buy a used car with a secondary air history?

Ask what was found, not what was replaced. A history with a software update, a relay or a program repair and a clean cold start afterwards is better than the same pump replaced twice. On a 2012 Tacoma or a 2005-2013 Tundra or Sequoia, ask which program, if any, the truck was in and whether the work is on the invoice. On a Subaru turbo, ask whether recall 16V738 was done and whether the relay was replaced when a pump was. On an Audi V6, ask for the flow readings before and after any port cleaning. The system only runs briefly after a cold start, so have the car scanned after a cold start too (our advice). A car with an open secondary air code is a price conversation, not a deal-breaker (our view): owners report $400 to $5,000 for a pump, valves or the whole system.

Clearing a secondary air code before an inspection

A cleared code returns if the cause is a valve, a pump or a port, and an inspection needs the car's self-checks to have run again (our advice). In the file, at least 12 owners say a car failed or could not pass a smog, emissions or safety inspection because of the secondary air system. 🟢 Mercedes-Benz warns that an open Smart fortwo combination valve could light the check engine lamp, which "could cause the vehicle to fail a state smog inspection" (11031591). Fix first, drive several normal trips including cold starts, then test. Our guide on how to reset a check engine light covers the mechanics.

What the papers tell a shop to do, checkpoint by checkpoint

Checkpoint 1 — the history: a cold start, freezing weather, altitude, a stretch of limp mode. Checkpoint 2 — the software: the label under the hood (Toyota), the engine software version (VW). Checkpoint 3 — the upstream part: relay (Subaru), vacuum solenoid (Audi 3.0T), vacuum test (A8 4.2), pipes (Aston Martin), the other bank (STI). Checkpoint 4 — the measurement: voltage and pressure rise (Tacoma, original issue), flow readings (Audi). Checkpoint 5 — the program, by VIN. Checkpoint 6 — the part, with the code that justifies it on the invoice.

Three secondary air traps

Trap 1 · Buying the pump from the code. Toyota's 20TC01 says "DO NOT replace the air pump unless these DTC’s are present", VW says not to replace before the update, and Subaru's recall replaces the relay first.

Trap 2 · Assuming a program still pays. Most Toyota programs are tied to ten years from first use, and our computation has them ended by time; F0A, JLG and 20TC01 print no end date (and Subaru's recall prints none), so ask which program, which date and which VIN rule.

Trap 3 · Replacing one valve. Lexus changed its paper from one bank to all parts, Subaru says check the other bank, and several owners write that a valve was replaced twice.

The secondary air plan: 10 minutes, today, this week

Today (10 minutes). Read all codes, write down what happened and whether it was cold, listen at the next cold start, look at the hoses with the engine off. Today (VIN). Enter your VIN at nhtsa.gov/recalls, then ask a dealer about a recall, campaign, program or software update for the secondary air system, giving the paper number from the atlas. This week. If the light is back, pay for one diagnosis, ask for the readings in writing and let the shop try the cheapest route first. If the car has stalled, lost power, shown reduced power or limp mode, failed to restart even once, or the check engine light is flashing, pull over safely, switch the engine off and have it towed (the one exception is a shop within 2 to 3 miles, reached gently, under 40 mph and on a light throttle). On a Subaru turbo, call a dealer about recall 16V738 today. On any car, if you smell smoke or hot plastic, stop, switch the engine off and call a tow; do not wait for the week.

These are composite scenarios, not individual customers: each starts from one owner report in the file, and the dollar figures are that owner's. If you drive a 2012 Tacoma at 91,000 miles that went into limp mode with P2445 and a dealer lists a valve, a pump, gaskets and labor (the bill in Route 5, ODI 10943863), ask for Toyota's 20TC01 and the T-SB-0333-17 revision by number, and for the pump code that justifies a new pump. If you drive a 2009 WRX with a check engine light and a pump that does not stop, pull over, switch off and call a Subaru dealer for recall 16V738 and the free towing; one owner whose relay was replaced under the recall was told the pump check would be charged (ODI 10956645). If you drive an Audi V6 with P0491 and P0492 stored together at more than 15,000 miles, ask for the flow readings that decide a port wash before a pump; one 2016 Q5 owner, with P0491 only, was billed $249 for the diagnosis and quoted $2,500 for cleaning (ODI 11714224).

Sources and documents

Primary documents only. Where a claim in this guide is marked 🟢, it rests on one of the items below, and the reference is given so you can pull the document yourself.

1. Toyota and Lexus, software updates and campaigns: T-SB-0079-16; L-SB-0038-16; T-SB-0033-12 Rev2; T-SB-0143-14; T-SB-0144-14; F0A (package, owner letter); D0E (scan, technical instructions, January 2015); T-SB-0024-13.
2. Toyota and Lexus, pump, valve and moisture programs: T-SB-0230-12 Rev1; POL11-05; ZG6 (POL17-02, dealer letter); ZHA (dealer package, POL18-01); ZLH (dealer package, POL17-01); T-SB-0333-17 and Rev1; 20TC01; L-SB-0028-14 Rev1 and Rev2; campaign JLG.
3. Subaru: recall 16V738, WTM-73R (read from the dealer bulletin and the owner letter; recall page); 11-147-14.
4. Audi, Volkswagen, Bentley: 2033001/2, 2033001/8, 2033001/26; 2035454/3 and 2035454/4; 2040403/1; 2035002/4; 2036558/3; 2039899/1; 2058095/1; 2049142/2; VW 2040202, 2040822, 24iM and dealer notice; Bentley TPI 2061064/1 and EA81.
5. GM, Mercedes-Benz, Aston Martin, BMW, Honda: GM 18-NA-061; Mercedes-Benz USA Smart fortwo notice and owner letter; Aston Martin SB-03-0450 and V2; BMW SIB 17 01 00; Honda 20-061.
6. PulsCar analysis of NHTSA public data, October 2026: 559 complaints about the secondary air system, each sorted twice by the same written rules; owner-reported amounts; the document list with check status and links. Complaints, amounts, documents, the sorting rules and how we did it (CC BY 4.0).

For the neighboring pages: what a check engine light means, the P0420 guide and the P0421 guide for the converter codes the cold-start system is meant to protect, P0171 for the lean code, P0300 for misfires, and a car running rough.

PulsCar does not diagnose a secondary air fault from the sound of the engine. For a code in this family, the reading, the VIN lookup and the documents above are the evidence.

Methodology. The complaint set is every complaint in NHTSA's file received from January 2015 to September 2026 (the file was searched to October 4) that names P0410 or a sister code (P0411 to P0419, P0491, P0492, P2430 to P2449), or describes the secondary air system in owners' words with a word about a fault, a repair or a symptom: 559 in all. Every complaint was sorted twice by the same written rules; the two sortings matched on the category in 92% of them (513 of 559), every disagreement was settled by a written rule, and a final check of the 76 complaints that both sortings had put under "nothing diagnosed" although the text mentions a dealer, a price or a warranty decision changed 43 of those rows. The document set is every NHTSA index entry whose summary names a code of the family or describes the secondary air system: 189 index entries, 186 with a file and 3 without. Model years, engines and build dates are as printed in the documents, never from NHTSA's index. Coverage status "as of September 2026" is our computation from printed terms. Amounts follow one written inclusion rule.

Prices verified October 2026: the dollar figures are owner reports, checked against the NHTSA complaint text; no repair-guide prices are used on this page. Technical documents verified October 2026: the 154 distinct documents in our published file, of which 88 were read in full, among them Toyota's F0A package, Subaru's WTM-73R and Audi's 2033001 family.

Had a secondary air code cleared by software, a relay, a program or a port wash, or a pump replaced for nothing? Email [email protected] with the vehicle, mileage and outcome.