P1326 Code in 2026: Hyundai and Kia's Bearing Alarm, What the Dealer Must Test, and Who Pays

P1326 is a message from software, not from a sensor that broke. It says the engine computer heard something it reads as a worn connecting-rod bearing.

P1326 — printed by Kia as a code "specific to the KSDS" and labeled "Knock Signal Range/Performance" in some bulletins, printed by Hyundai as P132600 in its campaign papers and P1326 in its repair procedures — is stored when the Knock Sensor Detection System (KSDS) hears the vibration pattern of connecting-rod bearing wear. The knock sensor is the same part that listens for detonation; the campaigns rewrote the engine computer so it also listens for a bearing. When it triggers, the check-engine light blinks continuously and the engine is held to about 1,800 to 2,000 rpm so you can reach a dealer before the bearing fails.

We went through every Hyundai and Kia manufacturer communication in NHTSA's index whose summary names P1326, the KSDS, the knock sensor, connecting rods, rod bearings, bearing clearance or long-block and short-block coverage, the recall files for the thirteen recalls those documents cite, and NHTSA's investigation records: 642 distinct files, 200 of which print P1326 in their own text. The documents agree on one thing: P1326 starts an inspection, not an engine order. The dealer's first step is a bearing clearance test, and a passed test ends in software or a knock sensor.

We also read 1,766 complaints from NHTSA's file, received from 2015 to 4 October 2026, that name P1326 or the KSDS, mention the knock sensor or its software on a Hyundai, Kia or Genesis, or describe the KSDS warning. Every complaint was sorted twice, independently, by the same written rules; the two sortings matched on the category for 1,610 (91%). 1,429 were about the system on the owner's car. Of the 870 that describe the code or the warning, 281 end with an engine replaced, approved, damaged or failed, 132 with a knock sensor or its wiring, and 384 with nothing found or done yet. Across all 1,429, owners report a refusal, a request to pay part of the cost, or paying for the repair themselves in 682 (a complaint count, not a refusal rate).

By the end you will know what the dealer has to test, which of five routes your P1326 is on, what each costs, which Hyundai or Kia program covers your engine in 2026, and what gets a claim refused.

Claims marked 🟢 rest on a document listed in the Sources section, gone through in full unless marked otherwise. Claims marked ⚪ are shop-price estimates carried from our repair guides. Owner-reported figures are what people told NHTSA, published with ODI numbers, and every complaint count here comes from the 1,766 complaints sorted twice and published.

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). P1326 is the opposite problem: the expensive answer is sometimes right, and the fight is over who pays for it. Every claim below that rests on a document names it.

What P1326 says: the software heard a bearing

Where the code comes from. 🟢 Kia's campaign bulletins put it in one paragraph: "The KSDS detects vibrations indicating the onset of excessive connecting rod bearing wear." Then: "If vibrations caused by bearing wear start to occur, the Malfunction Indicator Lamp (MIL) will blink continuously, and the vehicle will be placed in Limp Home Mode." And: "At that time, Diagnostic Trouble Code (“DTC”) P1326, specific to the KSDS, will be recorded in the ECU." (Kia's SC200 software bulletin, Rev 2 of June 2021, for 2011-2013 Optima Hybrid, 2012-2013 Sorento, 2012 Sportage and 2012-2015 Forte.) 🟢 NHTSA's closing summary of its engineering analysis EA21-003 describes the same software as "intended to detect impending engine failure, alert the driver, and limit engine power (to lessen likelihood of engine failure)."

What you feel. 🟢 "Engine RPMs will be limited to approximately 1800-2000 RPM." Kia's owner letters add: "This means the maximum vehicle speed will be limited to approximately 65mph or less depending on vehicle loading and road conditions." Hyundai renamed limp mode "Engine Protection Mode" in 2019, and its campaign 953 papers add a chime on certain vehicles. 🟢 Hyundai's dealer guide warns that the code may not set until the car has been driven through a normal drive cycle.

What it is not. P1326 is not a circuit fault in the knock sensor, the job of P0324 to P0334; our P0325 guide covers those codes and how the sensor became a bearing alarm. It is not a diagnosis either: every current procedure asks for a bearing clearance test before an engine.

First: P1326, P1327, P0325, or a code a reader called "knock sensor"?

Reading the exact code is the first check, and some owners in our file had it misread.

Search traps. Owners in our file wrote the code as P1236, PO1326 with a letter O, OBDP1326 and "code 1326". 🟢 Kia's recalls for the Nu 2.0L Soul and Seltos use the companion code P1327 for piston-ring noise, and the dealer replaces the engine if that code sets.

The campaign atlas: which Hyundai and Kia engines can set P1326

A car can only set P1326 if it carries the KSDS software. The software arrived through more than a dozen campaigns and recalls, each with its own number, vehicle list and coverage terms. Hyundai prints one set of numbers for the update and another for the follow-up repair.

Hyundai, Theta II 2.0L turbo and 2.4L GDI: campaign 953 for the software, T3G for the repair. 🟢 Campaign 953 grew from 2015 Sonatas in August 2018 to, by its 2019 revisions, 2011-2014 and 2015-2019 Sonata, 2013-2018 Santa Fe Sport, 2019 Santa Fe, 2014-2015 and 2018-2019 Tucson 2.4L and 2019 Veloster N 2.0T. 🟢 20-01-006H, February 2020, is the last 953 revision in our file. 🟢 Campaign T3G is the repair procedure for the same cars: "THETA GDI ENGINE DTC P1326 - ENGINE INSPECTION / REPLACEMENT" in 20-01-004H-3 and "ENGINE BEARING INSPECTION / REPLACEMENT" in 22-01-033H, April 2022.

Hyundai, other engines: campaign 966 for the software, T6G for the repair. 🟢 24-01-068H, August 2024, lists 2010-2012 Santa Fe 2.4L MPI, 2010-2013 Tucson 2.4L MPI, 2014-2015 Tucson 2.0L GDI, 2016-2021 Tucson 2.0L GDI, 2011-2015 Sonata Hybrid, 2016-2019 Sonata Hybrid and Plug-In, 2012-2017 Veloster 1.6L GDI, 2014 Elantra Coupe, 2014-2016 Elantra, 2014-2017 Elantra GT and 2018-2020 Elantra GT. Its purpose, in Hyundai's words: "enhance the knock sensor software to detect abnormal engine bearing noise before potentially severe engine damage occurs". 🟢 Campaign 982 (22-01-031H) gives 2017-2018 Sonata Hybrids that already had 966 a newer update. 🟢 The repair is T6G, 22-01-023H-2, November 2022.

Hyundai recalls that carry the KSDS. 🟢 20V-746 (Hyundai recall 198, 128,948 vehicles: 2012 Santa Fe, 2011-2013 and 2016 Sonata Hybrid, 2015-2016 Veloster) and 21V-727 (recall 209, 95,515 vehicles: 2017 Tucson and Sonata Hybrid) inspect the engine, replace it if bearing damage is found, and install the KSDS update. 🟢 The earlier Theta II recalls, 15V-568 (2011-2012 Sonata, 470,000) and 17V-226 (2013-2014 Sonata and Santa Fe Sport, 572,000), inspected and replaced engines before the software existed; the KSDS reached those cars through campaign 953.

Kia, Theta II: PI1802 and PI1803, then PI1805 and PI1806. 🟢 PI1802 covers 2014-2018 Optima, 2014-2018 Sportage and 2015-2018 Sorento built from late 2013 to mid-2018; its Q&A counts 1,059,479 vehicles. 🟢 PI1803 covers 2011-2013 Optima, 2014 Optima built at KMMG, 2012-2014 Sorento 2.4L and 2011-2013 Sportage 2.0L turbo, 614,689 vehicles, and must follow the SC147 recall inspection (17V-224). 🟢 PI1805 extends the update to 2019 Optima, Sorento and Sportage (193,863), and PI1806 to some 2020 Sportage (62,344). The follow-up repair procedures are the "W/X" bulletins of 2018-2019 and the "Y/Z" bulletins from 2020: 🟢 PI1802Y/Z Rev 7 and PI1803Y/Z Rev 7, March 2024, are titled "ENGINE REPLACEMENT INSTRUCTIONS FOR DTC P1326".

Kia, other engines: PI2002A and B, PI2101 to PI2108, and three recalls. 🟢 PI2002A and PI2002B update 2012-2016 Soul 1.6L and 2014-2016 Soul 2.0L; PI2101 the 2011 Sorento; PI2102 2010-2011 Forte and Koup; PI2103 2011-2013 Sportage 2.4L; PI2104 2014-2016 Optima Hybrid; PI2105 2016 Forte; PI2106 2017-2018 Forte; PI2107 2017-2019 Soul; PI2108 2019-2020 Optima Hybrid and Plug-In. The ten Q&As print vehicle counts that add up to 985,687 (our arithmetic). 🟢 Recalls 20V-750 (SC200, 294,756 vehicles: 2012-2015 Forte and Koup, 2011-2013 Optima Hybrid, 2012-2013 Sorento, 2014-2015 Soul, 2012 Sportage), 21V-844 (SC218, 2017-2018 Optima Hybrid and Plug-In, 10,731) and 23V-877 (SC291, 2011 Sorento 2.4L, 79,812) inspect the engine and install the software.

The 10-minute P1326 check

1. Read the code with a tool that shows maker codes, and photograph the screen (2 minutes). P1326 alone, or with misfire codes, oxygen-sensor codes or an oil-pressure light? Write the mileage down. Do not clear it: the dealer needs the stored code and its freeze-frame data, and several owners in our file say a dealer would not act once the code was gone. 🟢 Hyundai's procedures clear it only at the end of a repair: "Clear DTC P1326 with engine ON. P1326 may reset if not cleared with the Engine ON." A cheap reader does the job; our scanner guide covers what they show.

2. Check the oil level and look under the oil cap (2 minutes). 🟢 Every current Hyundai and Kia procedure begins here: photos of the dipstick, the underside of the oil filler cap and the filler opening. On a Kia, no oil on the dipstick, or sludge, lacquer or varnish under the cap, sends the claim to a maintenance review; on a Hyundai a dry dipstick means the oil is drained and measured, and less than 1.5 quarts goes to a prior approval before the bearing test. If the dipstick shows no oil, do not drive: tow.

3. Listen at idle with the hood up (2 minutes). A steady knock that rises with engine speed, a metallic rattle, or nothing unusual? 🟢 Hyundai's N-model bulletin applies only when "There is no abnormal engine noise present"; the bearing procedures branch on abnormal noise.

4. Find your paperwork (4 minutes). The date the car was first sold or put into service, the oil-change receipts, and any repair order that shows campaign 953, 966, 982, PI18xx, PI20xx, PI21xx, SC200, SC218 or SC291. The programs below count years from first delivery or first service, not from your purchase, and both makers can ask for oil-change records.

Then call a dealer with the VIN. nhtsa.gov/recalls shows safety recalls only; the product improvement campaigns and warranty extensions that carry most of the KSDS coverage are answered by the dealer or the maker.

Six P1326 situations, and which is yours

"Blinking light, limp mode, P1326, and the engine sounds normal." The software triggered; the test decides. → Route 3 if the test passes, Route 5 if it fails.

"Blinking light, limp mode and a loud knock, smoke or a burning smell." Stop driving. → Route 5.

"An Elantra N, Kona N or Veloster N after a car wash or heavy rain." Water in the connector. → Route 1.

"P1326 came back after the software update on a 2016-2021 Tucson 2.0L, or right after any campaign visit." A software or wiring issue is possible. → Routes 1 and 2.

"The dealer found low oil, sludge or a misfire before running the test." → Route 4.

"The engine seized or will not turn, with or without a code." → Route 5.

The P1326 price ladder, from the bottom up

The first two lines are what the programs pay for. The owner lines are what people told NHTSA they were quoted or charged when a program did not pay in full or did not apply, listed with ODI numbers; the ⚪ sensor figure is carried from our P0325 guide. The lowest engine figure is a $200 extended-warranty deductible; the next two are a $3,000 difference for a new engine instead of the used one an extended warranty approved and a $3,200 share quoted after Hyundai agreed to pay half.

What does P1326 cost to fix in 2026, and when is a new engine the wrong purchase? In PulsCar's review of 1,766 federal complaints, owners report 75 engine figures from $200 to $18,000, median $8,000, and 69 of them are quotes, not bills; 9 knock sensor figures run from $100 to $995, median $600. The campaign software, the bearing clearance test and an engine that fails the test on a qualifying car cost the owner nothing under the Hyundai and Kia programs. An engine is the wrong purchase when the bearing test has not been run, when it passed without bearing noise, when the car is an Elantra N, Kona N or Veloster N that set the code after rain or a car wash, or when the code returned on a 2016-2021 Tucson 2.0L right after its software update. Ask for the test result in writing before any quote.

The five P1326 routes, cheapest first

Route 1 · A false or early alarm: water, the software itself, a code cleared wrong — $0 under warranty

What it is. The KSDS listens through a knock sensor and decides with software. Water in the connector, an early software version, or an update that left the code coming back can all set P1326 on a healthy engine. The documents name each case.

What the documents say.

🟢 Hyundai 24-EM-010H, December 2024, 2022-2025 Elantra N, 2022-2023 Kona N, 2019-2022 Veloster N. "Certain Elantra N (CN7 N), Kona N (OS N), and Veloster N (JS N) vehicles may have DTC P1326 set due to water intrusion in the knock sensor connector during heavy rain or car wash conditions." And: "There is no abnormal engine noise present, and the vehicle may enter "limp home" mode." The repair is a new knock sensor and a spliced connector, 1.7 labor hours; the bulletin says "Normal warranty applies." It sets its own limit: "If the vehicle is experiencing any abnormal engine noise, this bulletin does NOT apply."

🟢 Hyundai 26-EM-014H (September 2026), superseding 24-EM-002H (March 2024), 2016-2021 Tucson 2.0L. "Some Tucson (TL) vehicles equipped with a 2.0L engine may exhibit a continued DTC P132600 after an ECM logic update has been performed per TSB 24-01-068H, Engine Monitoring Logic (Service Campaign 966)." Before any new software the dealer runs a mechanical pre-check: oil clean and changed within the last 3,000 miles or 6 months, coolant, spark knock from fuel or deposits, the knock sensor's mounting surface and torque, the connector pins, and a passed bearing test with no abnormal noise. If the code does not return on the test drive, "NO update or other steps are required." If it does, a manual-only update. Both versions have the pre-check; the 2026 revision drops the earlier requirement to call Hyundai's technical line first.

🟢 Kia's first KSDS software had errors twice. On 2014-2015 Optimas, PI1802 software installed before September 7, 2018 "has an error": Kia's owner letter (PI1802A1) says that once limp mode starts, "if driving above 20mph, the vehicle will decelerate slowly until it reaches 20mph", and after a stop only first gear engages. On 2017-2018 Optima Hybrids and Plug-Ins, the opposite fault: 🟢 SC218A says the original software "has an error and requires the installation of a corrected and updated KSDS software", and Kia's owner Q&A says it "will not correctly detect the vibrations indicating the onset of excessive connecting rod bearing wear in the engine, thus preventing driver warning and the initiation of limp home mode."

What the owners report. 44 relevant complaints end with software as the only repair stated, and 27 with a dealer that checked and found nothing or only cleared the code. Ten complaints concern an Elantra N or Kona N; eight of them mention rain, a car wash, water or a wet car. One 2023 Elantra N owner was told by a dealer that "the N models do that a lot in the rain or through carwashes, it triggers false knock sensor codes".

The cheap cause that gets skipped. The circumstances. Rain, a car wash or a software visit the day before the code are each named in a Hyundai or Kia document, and none of them needs an engine.

At the shop — say this: "Is this P1326 stored with abnormal engine noise or without? Which software version is on the car, and does a newer KSDS version or a bulletin such as 24-EM-010H or 26-EM-014H apply to my VIN?"

Route 2 · The wiring: interference, the extension harness and the connector — $0 under the campaigns

What it is. The knock sensor reports through its own wiring; on the N-model engines it is shielded beyond about 40 mm from the connector. Interference, a poor ground or corrosion can look like vibration. In 2018 and 2019 both makers treated P1326 first as a wiring question.

What the documents say.

🟢 Hyundai T3G, first version 18-01-032, October 2018, 2015 Sonata. "Follow the procedure to inspect the vehicle and install a wire harness extension or replacement engine based on the inspection results." The wiring signal check runs with the oil at "176° F (80° C) or greater"; a failed check meant a harness extension kit, 0.5 to 0.6 labor hours. 🟢 Hyundai's April 2019 re-test notice gives dealers a customer script saying the retest "narrowed down the repair to a small engine wire harness (and knock sensor) that was picking up interference".

🟢 Kia PI1802W/X Rev 1, November 2018, 2014-2015 Optima and Sportage and 2015 Sorento (later revisions extend the list to 2018). A scan-tool "Wiring Signal Interference Check", about three minutes at idle; "NOT OK" meant installing the Knock Sensor Extension Harness, moving the three knock sensor terminals at the engine computer and cutting off the old ones; "OK" meant an engine long block. 🟢 In April 2019 Kia's service action SA379 put held cars through an added engine noise inspection first, and warned dealers that "ALL claims for engine or harness replacement without the required diagnostic inspection/results or authorization are subject to claim chargeback/denial without exception."

🟢 From 2020 the bearing test replaced the wiring check as the first step in both makers' procedures. 🟢 The Tucson bulletin keeps the connector in the pre-check: "Clean the 2 pin connection points with an electrical contact cleaner and compressed air."

What the owners report. In 151 relevant complaints a knock sensor, its harness or its connector was the final repair; 132 of those describe the code or the warning. One 2017 Optima owner's dealer "PERFORMED WIRING INSPECTION AND REPLACEMENT OF KSDS (KNOCK SENSOR)", then a software update, and the light came back within 48 hours.

The cheap cause that gets skipped. The connector. A pin with green corrosion or a chafed wire is a few minutes for the dealer once the connector is exposed.

Fix it yourself. Leave the connector to the dealer. The bulletins reach it with the battery disconnected, which may erase the stored code, and on the N models by removing the intake manifold. 🟢 Hyundai's N-model bulletin also warns "Do NOT cut past 40 mm as the knock sensor wiring contains a shielded wire beyond this point to prevent external noise."

At the shop — say this: "Does a connector check apply to my car, such as 24-EM-010H on N models or 26-EM-014H on the Tucson 2.0L, and what did you find? Please write it on the repair order."

Route 3 · The knock sensor — owners report $100 to $995 for a sensor; ⚪ $200 to $500

What it is. The bearing clearance test is the hinge of every current procedure. A sealed tool pushes air and pulls vacuum through each cylinder in turn to measure how much the rod bearings move. A pass means the bearings measured within limits that day.

What the documents say.

🟢 Kia PI1802Y/Z Rev 3, July 2020. "If DTC P1326 is present, first perform the bearing clearance inspection with the Engine Bearing Clearance Tester device (SST KQ231-2T110QQK)." "This device checks the rod bearing clearance by placing air and vacuum into the cylinder block." "There are three (3x) rounds per cylinder to complete." The tool reports PASS or NO PASS; no clearance figure is printed.

🟢 What a pass leads to. In Kia's first Y/Z bulletins a pass with no knock meant a software update and a cleared code. From PI1802Y/Z Rev 4, November 2020, a pass means a software update if one exists and otherwise "Replace Knock Sensor"; 🟢 PI2103Y/Z adds "Only order replacement knock sensor if directed by the flowchart." 🟢 Hyundai's T3G and T6G flowcharts (22-01-033H, 22-01-023H-2) send a pass without abnormal noise to an oil change if due, then "New version of KSDS ECU update available?", and only if no update exists and the sensor has not been replaced before, "Replace Knock Sensor"; a car that already had one goes to Hyundai's technical line. Labor for the knock sensor runs from about 0.9 to 2.3 hours depending on the engine and the maker.

🟢 A pass is not the end of the argument. Hyundai's 2020 T3G dealer guide: "If a vehicle passes the bearing inspection test, but DTC P1326 comes back on after the code is cleared, contact Techline" (Hyundai's technical line). Noise is handled separately. In Kia's engine-noise flowchart a pass with connecting-rod bearing noise goes to a technical-line prior authorization and can end in an engine, while a pass without it is diagnosis coverage only, "Do Not Submit as a Campaign Claim". Hyundai's flowchart sends a pass with abnormal noise to its technical-support system with a video, and any engine needs a prior approval.

What the owners report. 9 owner figures for a knock sensor run from $100 to $995, median $600; only one of the nine says the bearing test had passed. Several owners describe a sensor replaced two or more times.

The cheap cause that gets skipped. The torque. 🟢 Hyundai's procedures set the knock sensor bolt at 21 Nm (15.5 lb-ft) and warn: "Improper installation can result in DTC codes."

Fix it yourself. Only after the dealer's bearing test passed, the dealer confirmed by VIN that no program and no newer software apply, and you kept the printout. Use the maker's sensor, clean the mounting surface, torque to the specification for your engine, and clear the code with the engine running.

At the shop — say this: "May I have the bearing clearance test result as a printout or screenshot, with the date and mileage? If it passed, is a newer KSDS software available before we replace the sensor?"

Route 4 · Oil and other causes found on the way — owners report $199.95 to $5,000, median $1,201.50

What it is. The current procedures inspect the oil before the bearings. Low oil, sludge, an overdue oil change or a misfire can end the visit with a different repair, or with a maintenance review that decides who pays for the engine.

What the documents say.

🟢 Hyundai 22-01-033H, April 2022. If there is no oil on the dipstick, the oil is drained into a container marked at 1.5 quarts: "If measured drained oil is below the 1.5-quart line:" the bulletin sends the car to a prior approval (PA) with photos and waits for Hyundai's answer. The bulletin's notice says "Poor oil maintenance reduces the engine oil lubrication and cooling capacities." 🟢 Hyundai's T3G dealer guide is explicit: "Engine oil consumption is not a condition that would qualify for an engine replacement under T3G."

🟢 Kia PI1802Y/Z Rev 7, March 2024. "If NO oil is registered on the dipstick, or oil lacquering, oil sludge and/or oil varnish is present (NG), then the engine is therefore suspect to maintenance neglect." Then: "Review of the vehicle's maintenance history is required." Kia checks dealer and Carfax records first; if they are insufficient it asks the customer in writing for records due within 10 days, and a finding of neglect leaves diagnosis coverage only.

What the owners report. 54 relevant complaints end with another repair named as the cause: plugs, coils, a catalytic converter, a fuel pump, a combustion chamber cleaning, an oil change. Owners report 38 figures for other repairs, from 35 complaints (10 of them in that group), from $199.95 to $5,000, median $1,201.50. By script, 187 of the 1,429 relevant complaints mention oil consumption, burning oil or adding quarts.

The cheap cause that gets skipped. The dipstick, before the engine runs again. A dry stick means tow, not drive; tell the dealer what you saw and bring your oil receipts, because on a Kia it starts a maintenance review and on a Hyundai the drained oil is measured.

At the shop — say this: "Before any other repair, was the bearing clearance test run, and what was the result? If you suspect maintenance, please tell me in writing which records you need and by what date."

Route 5 · Bearing damage: the engine — $0 under a program; owners report $200 to $18,000, median $8,000

What it is. The test fails, the crankshaft will not turn, or the engine has already seized or thrown a rod. The repair is a long block or, on some Kia programs, a short block, with the knock sensor moved over and the software updated.

What the documents say.

🟢 Hyundai 22-01-033H and 22-01-023H-2. A NO PASS result generates a draft prior-approval request, in 22-01-023H-2's words: "Please note that a PA and Engine Diagnosis Worksheet will be auto generated and SAVED in DRAFT if a "NO PASS" result is achieved." If the crank needs more than 94 lb-ft to turn, the dealer records it on video. Hyundai's 2022 TXXC bulletin adds: "A Warranty Prior Approval (PA) must be submitted on all applicable vehicles that exhibit the conditions above". 🟢 After a second NO PASS on re-inspection, Hyundai's 2019 T3G bulletins tell dealers "Do not inform the customer that they will need a new engine until approved by Warranty Prior Approval (PA)."

🟢 Kia Y/Z bulletins. NO PASS means replace the engine and update the software; a seized engine gets a prior authorization with a video of a 94 lb-ft torque attempt. Engine labor in the op-code tables runs from 5.3 to 9.4 hours depending on the model.

🟢 New or remanufactured. Hyundai's recall 198 bulletin uses a new engine within 5 years or 60,000 miles and a remanufactured one, if available, beyond.

🟢 Rental, diagnosis and money already spent. Hyundai's T3G and T6G dealer guides of 2019 to 2022, such as the June 2020 T3G guide, say every customer who arrives with P1326 or Engine Protection Mode "should be provided an SRC or alternative 3rd Party Rental" (a service rental car), paid "regardless of PA's decision", and: "Do not charge diagnosis for vehicles that previously had campaign 953 performed" (966 in the T6G guide). 🟢 Hyundai's campaign 953 Q&A sends owners who already paid for repairs to www.HyundaiUSA.com/campaignhome, and Kia's SC200 and SC291 recall letters offer reimbursement through Kia Customer Care for expenses paid before the letter.

🟢 After the engine. Recall 18V-907 (Kia SC172, 71,653 vehicles) inspected the high-pressure fuel pipe on Optimas, Sorentos and Sportages that had received an engine under SC147, a warranty or the KSDS campaign, because the pipe "may have been damaged, misaligned or improperly torqued during the engine replacement procedure"; Kia's letter says to stop driving and tow if you smell fuel.

What the owners report. 578 relevant complaints describe engine damage or failure without a replacement yet, and 73 an engine replaced, rebuilt or approved for replacement: 651 in all, 46% of the relevant complaints. 281 of the 651 also describe the code or the warning; the rest describe a failure with no warning reported, or one found at a dealer. 75 owner figures for an engine run from $200 to $18,000, median $8,000; 69 are quotes.

The cheap cause that gets skipped. The printout. A NO PASS result is a dated document; an engine quote without it is a guess.

At the shop — say this: "Please give me the bearing clearance test result, the prior approval number and the program you submitted it under. If it is denied, I want the reason in writing."

The coverage file: which P1326 programs still run in September 2026

The status column is our computation as of September 2026, the month of the latest documents in our set, from the terms each document prints; none of these documents prints your car's in-service date, so a dealer confirms it by VIN.

Hyundai TXXI, the lifetime warranty, and its conditions. 🟢 22-EM-001H, January 2022, superseded in April 2022 by 22-EM-001H-1: "The warranty coverage for engine long block repair or replacement regarding engine damage or malfunction from connecting rod bearing wear has been extended to a Limited Lifetime Warranty and is valid for original and subsequent owners." Then the box: "The warranty extension is limited to vehicles owned by individual consumers that have:" "Completed the Knock Sensor Detection System software update (Campaign 953) AND" "A check engine warning lamp illumination with DTC P1326 (Campaign T3G) OR" an engine concern related to connecting rod bearing wear. "Additional limitations apply." The April revision drops that box and refers instead to the settlement's requirements on the software update, vehicle neglect, branded or salvage vehicles and certain commercial owners. The class settlement behind TXXI is covered in our Hyundai and Kia engine guide.

Hyundai TXXM, 15 years. 🟢 22-EM-006H-2, November 2022: "The warranty coverage for engine repair or replacement regarding engine damage or malfunction from connecting rod bearing wear has been extended to 15 years or 150,000 miles from the date of original retail delivery or date of first use, whichever occurs first, and is valid for original and subsequent owners." A car first used in September 2011 reaches 15 years in September 2026. 🟢 The same text excludes "Commercial entities and individuals engaged in the buying, selling, leasing, or renting of motor vehicles, as well as salvaged vehicles". 🟢 Hyundai's March 2026 dealer notice for TXXM and T6G (announcing bulletin 26-01-033H) repeats the terms, and its customer script adds that if a car has not received the KSDS, "Hyundai will still consider eligibility for the warranty extension for the time being."

Hyundai TXXC, 10 years. 🟢 22-EM-002H-1 extends the long block to "10 years or 120,000 miles from the date of original retail delivery or date of first use, whichever occurs first." By September 2026 that covers only cars first delivered after September 2016; it matters most for the 2019 Veloster N, which is not on the TXXI list.

Kia's lifetime promise, for P1326 only. 🟢 Kia's 2019 PI1805 dealer letter: "Kia is providing lifetime engine warranty coverage for this issue only (DTC P1326), to both new and used vehicle owners of the affected 2019 MY vehicles identified above, for engine long block assembly repairs needed due to resulting bearing damage upon completion of this Product Improvement Campaign." The 2018 PI1802 and PI1803 dealer letters and Q&As carry the same "this issue only (DTC P1326)" wording; the owner letters promise lifetime long-block coverage for connecting rod bearing damage without naming the code. 🟢 The PI1806 letter for 2020 Sportage prints no warranty sentence at all. 🟢 Kia's later repair bulletins add a line the letters do not: "Certain limitations may apply to this Product Improvement Campaign coverage."

Kia's 15-year terms. 🟢 For the Soul, Forte, 2011 Sorento, 2011-2013 Sportage, Optima Hybrid and the recall cars: "Upon completion of this software update, Kia will warrant any engine long block assembly repairs needed due to connecting rod bearing damage for 15 years/150,000 miles starting from the first date of service, whichever occurs first, for both new and used vehicle owners." (Kia's September 2021 Soul renotification, which adds that the coverage is "ONLY available IF the KSDS software is installed".) 🟢 The 2012-2016 Soul 1.6L started in February 2020 at 10 years or 120,000 miles on the short block and moved to 15 years or 150,000 miles on the long block in March 2021. 🟢 The SC218, PI2107 and PI2108 letters add "provided the vehicle has had regular oil change in accordance with the maintenance requirements set forth in the vehicle's Owner's Manual". For most 2011 Sorentos in SC291, fifteen years from first service has already run out.

The software as a condition: it changed. 🟢 January 2022, Hyundai's TXXI dealer guide: "If 953 is open, then KSDS is not installed. Service consultant to explain to customer that engine is not covered by the extended warranty." 🟢 April 2022, Hyundai's T3G guide: the flowchart "has been revised to remove KSDS prerequisite (Service Campaign 953)". 🟢 November 2022 onward, the TXXM notice: "Customers are strongly encouraged to complete the KSDS installation, which has been communicated to customers as a requirement for coverage under the extended warranty.", followed by "Regardless of KSDS completion, dealers should follow the notice described below and always submit a Warranty Prior Approval request". 🟢 Kia's 2023 PI2103Y/Z flowchart: "KSDS requirement waived until 11/04/2023". Recall 198 and 209 cars, whose recalls installed the software, are exempt from Hyundai's KSDS requirement.

What gets a P1326 engine claim refused

Maintenance, by the maker's definition. 🟢 Hyundai's July 2023 dealer guide (TXXM/T6G best practice): when an inspection gives "a reasonable basis to suspect maintenance neglect", the "Dealer must inform customer that maintenance neglect is suspected and ask the customer to provide all oil change receipts", and the customer gets up to 10 business days. 🟢 Kia's PI2103Y/Z, June 2023, read from its page image: "Exceptional Neglect" is one oil-change gap of more than 14 months and/or 10,500 miles, or an oil-consumption diagnosis the owner did not have repaired within 30 days or 1,000 miles; owners get five business days to respond and ten to produce records; owners who change their own oil may submit a log with receipts for oil and filters; and no neglect finding applies to an otherwise eligible failure in a car's first 15,000 miles.

Ownership and title. 🟢 Hyundai's TXXM terms exclude commercial owners, dealers and salvaged vehicles; TXXI's April 2022 revision says the settlement has requirements on branded or salvage vehicles and certain commercial owners. 🟢 Kia's 2024 flowcharts: "Validate Ownership — Initiate a T/L case" (a technical-line case) "if the vehicle has a salvage title, belongs to a used car dealer, franchise, or auto auction."

The software. See above: required in Kia's letters and in Hyundai's 2022 TXXI guide, waived or discretionary in later Hyundai documents.

Driving on. 🟢 Kia's owner letters: "The Kia service technician will be able to read how long you have driven your vehicle after the KSDS is activated." And: "an abusive failure to take the vehicle to a Kia dealer after KSDS activation may void the extended warranty KMA is providing with completion of this Product Improvement Campaign."

What owners say they were told. In our reading, 682 of the 1,429 relevant complaints report a refusal, a denial, a demand to pay part of the cost, or an owner who paid. By script (counted, not sorted), 47 of those 682 mention a previous, second or prior owner or buying the car used, 46 maintenance records or receipts, and 19 a salvage, branded or rebuilt title (the script matched 23; reading removed four about a salvage engine or value). One Santa Fe Sport owner quoted Hyundai's reply: "Per the terms of the extended warranty, the campaign 953 software must have been installed on the vehicle prior to bearing malfunction." A 2011 Sonata owner wrote that Hyundai "denied my engine replacement, saying there was a gap in service history between 2021 and 2025", years the owner did not own the car.

What 1,766 complaints about P1326 and the knock sensor software show

How we went through them. We went through every complaint in NHTSA's file received from 2015 to 4 October 2026 that names P1326 in any spelling we could find, names the KSDS or the knock sensor detection system or "engine protection mode", or, on a Hyundai, Kia or Genesis, mentions the knock sensor or describes a blinking light with limp mode: 1,457 from our first search. Before sorting the rest, an independent search looked for what the first had missed and added 309. Every complaint was sorted twice, independently, by the same written rules, fixed before the sorting; the two sortings matched on the category for 1,610 of 1,766 (91%). 1,429 were about the system on the owner's car; 337 were not, mostly ordinary knock-sensor faults and a blinking light with no link to the system.

Is the engine about to fail? Of the 870 complaints that describe P1326 or the warning on the owner's car, 281 end at the engine (240 damaged or failed, 41 replaced or approved), 132 at the knock sensor or its wiring, 34 at another cause, 19 at software, 20 with nothing found, and 384 with no outcome yet. Complaints come from owners whose trouble did not end, so these shares are not a forecast for your car; the bearing test is.

Coverage. 62 complaints say Hyundai, Kia or the dealer paid, or agreed to pay, the whole repair or did it free; 682 report a refusal, a share to pay, or an owner who paid. Of the 73 engine replacements, 36 were covered and 25 involved a refusal or an owner share at some point. Of the 578 damaged or failed engines without a replacement, 412 report a refusal, a share to pay or an owner who paid. 485 relevant complaints print P1326 itself.

The software. 388 complaints say the knock sensor software was installed on the car at some point. 190 of the 651 engine complaints say so as well, some installed before the failure and some after. One 2015 Sonata owner: "No warning lights (I had the knock sensor recall performed). Engine simply locked up solid."

Which cars. Kia 742, Hyundai 687. By model: Sonata 279, Optima 267, Soul 181, Tucson 158, Sorento 140, Sportage 95, Santa Fe 86, Santa Fe Sport 72, Forte 48 and Veloster 37. These are complaints, not cars: popular models produce more of them, and nothing here is a failure rate.

When and how old. 5 complaints in 2018, 97 in 2019, then 56, 139, 223, 226, 195 and 260 from 2020 to 2025, and 228 in 2026 through 4 October. The median model year is 2016. Among the 380 complaints that give a mileage between 1,000 and 400,000, the median is 93,738.5 miles.

What do 1,766 federal complaints about P1326 and the knock sensor software say about whether the engine is about to fail? PulsCar went through every complaint from 2015 to 4 October 2026 about P1326, the Knock Sensor Detection System or the knock sensor on a Hyundai or Kia, sorting each twice by written rules. 1,429 were about the system on the owner's car. Of the 870 that describe the code or its blinking-light warning, 281 end with an engine damaged, failed, replaced or approved for replacement, 132 with a knock sensor or its wiring, 34 with another cause, 19 with software, 20 with nothing found, and 384 with no outcome yet. Across all 1,429, 682 report a refusal, a share to pay or an owner who paid, and 62 say the maker or dealer paid in full. The shares describe owners who wrote to NHTSA, not every P1326 car. The deciding fact for a car is the bearing clearance test result.

What owners say they paid

Of the 1,429 relevant complaints, 141 state a dollar figure tied to the repair, 167 figures in all: 112 quotes, 30 amounts paid, 20 bills and 5 where the narrative does not say. The figures are what owners wrote, not audited invoices, and we publish them with ODI numbers.

The top diagnosis figure is a $5,000 quote to tear an engine down to see whether it qualified. The two software figures come from owners who say they were charged for the update. Towing, rentals, loan balances, vehicle values and unrelated repairs were left out, each with a reason in our working files. Engine figures are almost all quotes because owners report the number that frightened them, whether or not they paid it.

Why P1326 comes back after a repair

Because the repair did not touch what the software heard. A knock sensor or harness replaced on an engine whose bearings are worn will report the same vibration. 🟢 Hyundai's 2020 dealer guide anticipates it: a car that passes the bearing test and sets P1326 again goes to its technical line; its T6G flowchart sends a car that already had the newest software and a new knock sensor to the same place.

Because the software changed. 🟢 Kia added update events with "Misdiagnosis Prevention Logic Improvement" in their names to PI1802, PI1803 and PI1805 in 2020 without saying what changed, corrected the 2014-2015 Optima version in 2018 and the 2017-2018 Optima Hybrid version in 2022; Hyundai gave 2017-2018 Sonata Hybrids a second update under campaign 982 and 2016-2021 Tucsons a manual-only update in 2024 and 2026. A code that returns after a software visit can be the new version doing its job or an old version misreading.

Because the code was cleared wrong. 🟢 "P1326 may reset if not cleared with the Engine ON." Owners in our file describe parts stores and independent shops clearing the code, and one 2016 Tucson owner wrote that the dealer "refused to perform the campaign repair, stating no active code was present at that time."

Because water came back. On the N models, the connector repair in 24-EM-010H is the documented fix.

Why does P1326 come back after the knock sensor or the software is replaced, and what should the second visit check? Because the first visit may have fixed the messenger and not the message. In PulsCar's review of 642 maker, recall and investigation files, a passed bearing clearance test with no noise leads to a software check and then a new knock sensor, and Hyundai's 2020 dealer guide tells dealers to contact its technical line if P1326 returns after a passed test. Kia corrected two early versions of its software, one that slowed 2014-2015 Optimas to 20 mph and one that could not warn on 2017-2018 Optima Hybrids. Hyundai's 2026 Tucson bulletin checks the oil, fuel, carbon, the sensor's torque and connector before a manual update. A second visit should ask for the test result, the software version, the connector inspection and whether the code was cleared with the engine running.

Can you drive with P1326?

Only to a safe place and the dealer. 🟢 Kia's letters say the car "can continue to be operated for a limited time in Limp Home Mode to permit you to drive the vehicle to a safe location", at about 1,800 to 2,000 rpm and 65 mph or less, and warn: "If you ignore the blinking MIL and continue to drive your vehicle in Limp Home Mode for an extended number of miles, your vehicle may eventually experience severe engine damage and stall."

Stop and tow if: you hear knocking or a metallic rattle, the oil-pressure light comes on, or you smell burning or see smoke. 🟢 Kia's 2011 Sorento recall letter lists "engine noise, illumination of the Check Engine Light, burning smell, or smoke" and says: "If this occurs, pull over to a safe location and contact Kia Roadside Assistance at 1-800-333-4542". Kia's recall files describe 20V-750 and 23V-877 as engine compartment fires and 21V-844 as engine damage that may cause a stall or fire.

Should you buy a used Hyundai or Kia with a P1326 history?

Ask for three papers. The repair order that shows the knock sensor software campaign on the VIN, every oil-change receipt, and the first in-service date. 🟢 Kia's owner letters ask owners to keep the letter in the glove box and pass it to the next owner; Hyundai's TXXI and TXXM terms follow the car to later owners, and the 15-year terms count from first delivery or first service.

Green flags: a bearing clearance test result marked PASS, the software campaign done, a documented engine replacement under a program, receipts with no gap longer than Kia's 14 months and/or 10,500 miles.

Red flags: a salvage or branded title, or a car that belongs to a used-car dealer, franchise or auction (Kia's 2024 flowcharts open a Techline case for each), a P1326 cleared without a repair order, no oil on the dipstick, a 2011 Sorento or other car whose 15 years from first service have already passed. Our used-car inspection checklist covers the rest of the walk-around, and our model guides for the Sonata, Tucson, Sorento and Soul cover the other common faults by mileage.

Clearing P1326 before an inspection

Clearing the code does not fix it and does not pass an inspection: it resets the readiness monitors, which many inspection programs check, and a real bearing signal sets the code again. Have the dealer read and record it, run the bearing test, and clear it with the engine running as the bulletins say. Our reset guide explains the monitors.

What a dealer actually does with P1326, checkpoint by checkpoint

Checkpoint 1: the code and the freeze frame — P1326 or P132600, screenshot saved, VIN visible.

Checkpoint 2: the oil — dipstick, oil cap and filler opening photographed; if the stick is dry, drain and measure.

Checkpoint 3: external damage and rotation — lower-end damage to the cylinder block photographed, and a crankshaft that will not turn two full turns at 94 lb-ft recorded on video.

Checkpoint 4: the bearing clearance test — PASS, NO PASS, or no test with an error code.

Checkpoint 5: noise — a pass with abnormal noise is diagnosed through the maker's technical-support system with a video, and any engine needs a prior approval.

Checkpoint 6: software, then the sensor — a newer KSDS version if one exists, otherwise a knock sensor.

Checkpoint 7: prior approval — any engine replacement waits for the maker's approval; in Hyundai's 2022 TXXI guide, a dealer that finds a car ineligible documents the reason on the repair order.

Three P1326 traps that cost owners the most

Trap 1: the cleared code. A parts store or shop clears P1326 to get the car moving, and the dealer then has no code to diagnose. 🟢 Hyundai says the code may reset if it is not cleared with the engine running. Lesson: let the dealer read it first, and keep a photo of the screen.

Trap 2: the missing update on a used car. The previous owner ignored the campaign letter, and the claim is refused because the software was never installed. 🟢 Kia's letters make the coverage conditional on the update; Hyundai's 2022 TXXI guide did too, while its later notices tell dealers to submit a prior approval regardless. Lesson: check the campaign on the VIN the day you buy, and get it done.

Trap 3: the oil-change gap. 🟢 Kia's 2023 rules count one gap of more than 14 months and/or 10,500 miles as neglect, and Hyundai gives owners up to 10 business days to produce receipts. Some owners in our file who bought used could not produce records from before their purchase. Lesson: keep every receipt, including the oil and filter you buy for your own changes.

Three P1326 claims, decoded

These are composite scenarios, not individual customers: each combines details from the documents and complaints above.

Scenario 1: 2016 Kia Sorento 2.4, 98,000 miles, blinking light and limp mode on the highway, bought used. The owner checks the oil (full, but the photos show varnish under the cap), has the car towed, and asks the dealer whether PI1802 is done on the VIN. It is; the varnish sends the claim to a maintenance review, and the bearing test returns NO PASS. The owner has receipts for the two years they have owned the car and the dealer's Carfax shows the rest. The engine is replaced under the lifetime promise in Kia's letter. Lesson: the test and the records decide the bill, and the records include the years before you owned the car.

Scenario 2: 2023 Hyundai Elantra N, 18,000 miles, P1326 and limp mode the morning after a car wash, engine quiet. The dealer finds water in the knock sensor connector and replaces the sensor and splices the connector per 24-EM-010H, under the warranty the bulletin applies. Lesson: on an N model, the circumstances point to the connector before the engine.

Scenario 3: 2018 Hyundai Tucson 2.0L, 110,000 miles, P1326 back two weeks after the campaign 966 update. The dealer runs the 26-EM-014H pre-check; the oil is recent, the connector clean, the bearing test passes with no noise, and the code returns on the test drive, so the manual-only update is installed. If the bearing test had failed instead, this car would fall inside TXXM's 15 years from first use, subject to the prior approval. Lesson: on this engine, a returning code after the update has its own bulletin.

The P1326 plan: 10 minutes, today, this week

10 minutes: read and photograph the code; check the oil; listen at idle; find the in-service date and the oil receipts.

Today: if you hear knocking, smell burning, see smoke or the oil light is on, stop and tow. Otherwise drive gently to a Hyundai or Kia dealer, or tow if it is far. Ask by VIN about the knock sensor software campaign, bulletin 24-EM-010H on N models, 26-EM-014H on 2016-2021 Tucson 2.0L, and the extensions TXXI, TXXM and TXXC.

This week: get the bearing clearance test result, the prior approval number and any denial reason in writing, and a rental or alternate transportation if the car stays. If you already paid for a P1326 repair, ask the maker for reimbursement.

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. Claims marked ⚪ are shop-price estimates carried from PulsCar's repair guides — estimates, not measurements from a dataset we own.

1. Hyundai software campaigns: 953 20-01-006H and its dealer best practice v13; 966 24-01-068H; 982 22-01-031H.
2. Hyundai repair procedures: T3G 18-01-032, 20-01-004H-3 and 22-01-033H; T6G 22-01-023H-2; T3G dealer guides of June 2020 and April 2022, and the 2019 re-test notice; Tucson 24-EM-002H and 26-EM-014H; N models 24-EM-010H.
3. Hyundai warranty extensions: TXXI 22-EM-001H, 22-EM-001H-1 and its dealer best practice; TXXM 22-EM-006H-2, the July 2023 best practice and the March 2026 dealer notice; TXXC 22-EM-002H-1.
4. Kia campaigns and letters: PI1802A1 owner letter; PI1805 dealer letter; PI1806 dealer letter; PI2002A renotification; PI1802 and PI1803 dealer letters (1, 2); PI2107 Q&A and PI2108 owner letter.
5. Kia repair procedures: PI1802W/X Rev 1; SA379; PI1802Y/Z Rev 3 and Rev 7; PI1803Y/Z Rev 7; PI2002Y/Z Rev 3; PI2103Y/Z.
6. Recalls: Hyundai 15V-568, 17V-226, 20V-746, 21V-727, and 17V-578 for 2017 Santa Fe 3.3L bearing wear; Kia 17V-224, 18V-907, 20V-750, 21V-844, 23V-877; piston-ring recalls 21V-259, 21V-301 and 25V-099.
7. NHTSA investigations: EA21-003 (closed 5 February 2024), PE19-003 and PE19-004, RQ17-003 and RQ17-004, DP18-003, read from NHTSA's investigation file.
8. PulsCar analysis of NHTSA public data, October 2026: 1,766 complaints about P1326 and the knock sensor software, 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.

For the neighboring pages: the P0325 guide for knock sensor circuit codes, Hyundai and Kia engine knocking for the class settlement and the engine recalls, engine knocking sound, the flashing check engine light guide, car won't accelerate and the code index. If you are choosing a reader that shows maker codes, our OBDLink MX+ review covers one.

PulsCar's free sound check listens to a short recording of an idling engine. It does not read codes or measure bearing clearance; for P1326, the dealer's test and the documents above are the evidence.

Methodology. The complaint set is every complaint in NHTSA's file received from 2015 to 4 October 2026 that names P1326 in any spelling we searched, names the KSDS, the knock sensor detection system or engine protection mode, or, on a Hyundai, Kia or Genesis, mentions the knock sensor or a blinking light with limp mode — 1,766 in all. Every complaint was sorted twice, independently, by the same written rules, fixed before the sorting, with an addendum fixed before the second batch (the two sortings matched on the category for 1,610 of 1,766, 91%). Every disagreement was settled under written rules published with the sorting rules, and two final checks corrected 65 entries on which the two sortings had agreed. Owner amounts are every dollar figure a relevant complaint ties to the repair, classed as quoted, paid, billed or not stated. The documents are every NHTSA manufacturer communication whose index summary names P1326, the KSDS, the knock sensor on a Hyundai or Kia, connecting rods or bearing clearance, plus what an independent audit added, the files of the recalls they cite, and six investigation records: 642 distinct files after removing byte-identical copies, 200 print P1326. Every quotation was checked by script against the document or complaint text. Counts are complaints, not cars, and nothing here is a failure rate. Coverage status "as of September 2026" is our computation from the terms each document prints. The data are published under CC BY 4.0.

Prices verified July to October 2026 in the repair guide they are carried from and in the owner reports above, and reviewed quarterly. Technical documents verified October 2026: the 642 distinct files we went through, listed in our published file — among them Hyundai 26-EM-014H (September 2026), 24-EM-010H, 22-EM-006H-2 and the March 2026 TXXM notice, and Kia PI1802Y/Z Rev 7.

Had P1326 cleared by a sensor, a connector or software, or an engine approved or refused? Email [email protected] with the vehicle, mileage and outcome.