2017 Hyundai Santa fe

On May 26.2026, Southern States Hyundai performed mandated Service Campaign 9C2 (Theta II Emissions Improvement). The software immediately caused drivability degradation and a catalytic converter failure, mirroring the defects Hyundai acknowledged to the NHTSA on May 18, 2026. Corporate customer care is using an unrelated oil consumption testing protocol to deflect liability and charge me $1,400 for the testing and/or $4002 for the catalytic converter out of pocket for damage caused by their own recall software. This hesitation is a severe safety risk when accelerating into traffic.

My truck began emitting a strong oil odor on XXX. I took it to Amato in [XXX], where I was told the oil pan was leaking. They replaced the oil pan, and I paid for the inspection as well. About an hour after picking up my truck, the check‑engine light came on. I returned to the dealership, and they then said additional repairs were needed, even though I had already paid $2,211.57 for the work they claimed was necessary. At that time, my truck had 145,776 miles on it. Because the manager at [XXX] refused to address my concerns, I was told to go to another Amato location, and I was effectively blacklisted from the first dealership. I went to Amato Glendale, where I experienced the same issues. They fixed only one of the problems, and that was only after I contacted Hyundai corporate. My truck continued to have oil‑consumption issues. Amato required me to complete a three‑month, 1,000‑mile oil consumption test before they would consider providing assistance. I completed the test as instructed. Now, however, they are saying that due to the age and mileage of my truck, they will not cover the engine replacement — even though the problems began at 145,000 miles, not 156,000. Other drivers have reported that Hyundai delays necessary repairs until major engine damage occurs, and I believe that is exactly what has happened in my case. There was also a suspension recall that applied to the 2018 model but not the 2017. Amato Hyundai covered part of that repair only because I contacted corporate again. My current complaint is about the failing engine and Amato Hyundai’s lack of responsibility in properly diagnosing and repairing my truck. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Cold-Start Hesitation & Rough Shifting: Following the 9C2 ECU update, my vehicle is experiencing a brief period of throttle hesitation, rough shifting, or jerky transmission behavior specifically during cold-start operations.

Known as an issue with Hyundai, but unresponsive to correct because no diagnostic code is sent. Transmission will shift extremely hard from 1st to 2nd gear randomly. In keeping track of the mileage, this appears to happen every 200 miles or so. Also, it faild to upshift correctly, making the entire car shudder. Also, at times it will not go into reverse gear. On one occasion, after finally doing so, it slammed so hard into reverse I almost collided with the car behind me.

My 2017 Hyundai Santa Fe, purchased new from Lynnes Hyundai in February 2017, has approximately 93,000 miles. The vehicle previously developed a significant oil-consumption/engine problem that was diagnosed by Hyundai, and Hyundai replaced the engine with a remanufactured engine. Approximately two weeks after the engine replacement, the check-engine light illuminated and DTC P1326 was identified. The dealership replaced the knock sensor. Approximately two weeks later, the check-engine light illuminated again with a recurring P1326 condition. The vehicle is currently at Lynnes Hyundai and has been there approximately three weeks while they attempt to determine the cause. Hyundai Techline is involved. Prior to the current repair visit, while traveling approximately 60 mph, the vehicle experienced a very forceful hesitation that jerked the vehicle. I immediately slowed down and pulled onto the shoulder. The vehicle continued to hesitate intermittently while I drove slowly to safety. I was concerned that the vehicle could lose power or shut down while I was driving at highway speed, creating a risk of a crash. The recurring P1326 condition has been confirmed by the Hyundai dealership. The vehicle and engine have been inspected by Hyundai/Lynnes Hyundai multiple times, including after the engine replacement. The current recurring condition has not been resolved. The check-engine light is the warning lamp associated with the current condition. I do not know the underlying cause of the recurring P1326 condition; Hyundai is currently attempting to diagnose it. The vehicle is currently available for inspection at Lynnes Hyundai.

My 2017 Hyundai Santa Fe 3.3L V6 (148,000 miles) has documented oil consumption and a recurring DTC P0278 (Cylinder 6 Contribution/Balance). Hyundai's formal oil-consumption test confirmed oil consumption, but said it was below the threshold for combustion-chamber cleaning. The check-engine light and P0278, and losing acceleration ability continue to recur. The vehicle is available for inspection. Hyundai has confirmed the oil-consumption issue but has not determined the cause of P0278 or performed the TXX8 engine inspection I am requesting. I am concerned about worsening engine performance, loss of power, or engine failure, particularly given Hyundai's history of engine-bearing issues with certain 2017 Santa Fe 3.3L engines. I am not claiming diagnosed bearing failure; I am requesting a TXX8 inspection to determine whether an eligible engine condition exists. I have contacted both the dealership and Hyundai Corporate, but have been told I must repeat the oil-consumption test. At 148,000 miles, I am requesting prompt inspection before the 150,000-mile TXX8 limit and covered repair/replacement if an eligible condition is found.

Directly after the dealer, Johnson Hyundai of Apex, completed Service Campaign 9C2 on 4/28/26, my vehicle began sticking, surging, and harshly changing gears. I have followed up with the dealer multiple times. They said they are not getting back any diagnostic error codes (outside mechanic shop also confirmed they're also not seeing error codes), but went ahead and recalibrated the ECM. They told me to drive for 200 miles and the issue should be resolved. I have now driven 1,500 miles and the issue persists. I'm now seeing Hyundai put out a 'Driveability Communication" about this issue, but there is no proposed fix/recall. This issue did not exist before this service campaign was performed by the dealership.

There is a class action lawsuit for the Theta Engine in some Kia and Hyundai vehicles and my type of vehicle falls into this lawsuit category. I drive a 2017 Hyundai Santa Fe Sport and what the lawsuit described what happened to my vehicle, it seized up and you’re supposed to have a lifetime warranty for this problem. I submitted all the paperwork and Norman Hyundai sent videos it was seized up but denied my claim so I have a car that no longer drives with a car loan still so can’t buy a new vehicle. I was told they didn’t see oil additive anytime but their own business this in March ‘26 and May ‘26. It states on the lawsuit if anyone’s in the class action lawsuit they are covered if this happens to your vehicle. Also, part of the lawsuit is the oil consumption and how much it’s eating gas and then it seizes possibly or catch fire and my car was barely getting a 1,000 miles and it would be empty so couldn’t keep up always checking it and the car seized up due to what’s supposed to be covered.

After the update earlier this summer for an emissions issue, my car, a 2017 Hyundi Santa Fe Sport, has not run right. When it is cold, the first trip on the day, it hesitates and sputters to an extent that it is not safe on the nearest highway where the speed limit is 35. We have been compensating by driving slowly around the neighborhood for a few minutes, and then it's fine. It has been happening since the update of service campaign 9C2, the "Theta II Emissions Logic Improvement" recall. The local Hyundai dealer has been unable to provide a fix. We just picked it back up today, 8/21/26, after deciding against their latest idea, a fuel injector treatment for $200. Based on other examples I've read with similar or identical issues after the recall software update, I have concluded this is a safety issue that Hyundai must resolve.

We have been involved with an Oil Consumption problem since 2025 maybe earlier. No leaks just an over use of oil. I have had to fill it myself or take it to the dealer. They did testing and di some kind of cleaning that took 8 hours. We still have the problem and while driving the whole car shut down. No power in the middle of a highway. This has now happened twice and the first time we had to call AAA for help. It showed an engine sign and we checked the code. First it was an small air leak but they didn't find anything. It came up again, same message so we replaced the gas cap, but the oil was still disappearing and the car had shut down again. I spoke with the Hyundai corporation and they said to do the combustion cleaning again. So we set it up but found out that we had to pay for it so we declined. They refused to do anything about the car. We later found there were other cars made by the same company with the same problem. I did some research and they have had an Oil Consumption problem for quite a while. Now the Catalytic Converter is showing up as having problems. Well that's where the oil goes and can shut down the car due to airflow. They never disclosed it to us face to face, we had to find out about it after the the warranty was up. That was very dangerous to have stopped on a highway.

Complete unmitigated loss of acceleration and power while traveling at highway speeds, creating an immediate life-threatening road hazard. Following a warranty engine replacement and mandatory dealer software flash at Clay Cooley Hyundai (Sherman, TX), the vehicle began experiencing powertrain communication issues. While operating the vehicle at 65 MPH on the highway, the vehicle completely failed to accelerate and lost propulsion power, nearly resulting in a catastrophic rear-end collision with an oncoming 18-wheeler semi-truck. Dealership diagnostics claim "no trouble codes present," but live data telemetry confirms the High-Pressure Fuel Pump (HPFP) is actively commanding and delivering a dangerous 1,600 PSI to the fuel rail at hot idle. This abnormal fuel delivery is paired with a severe powertrain stutter in 3rd gear. Service personnel at multiple locations confirm a widespread, high volume of transmission failures and severe drivability issues specifically tied to this recent Hyundai software update. Corporate has denied repair coverage. The vehicle remains an active highway safety hazard and is completely undrivable.

The contact owns a 2017 Hyundai Santa Fe. The contact stated that while reversing, the vehicle jerked and shuddered abnormally. Additionally, the transmission hesitated, and the vehicle almost stalled. No warning lights were illuminated. The vehicle was taken back to the dealer where the contact was informed that the Service Campaign Number: 9C2 was completed. The contact was informed that the updated software was confusing the transmission and had caused the failure. The contact was informed that the remedy was not yet determined. In addition, the contact was informed that the dealer was waiting on instructions from the manufacturer. The vehicle was not repaired. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 63,036.

Was driving down highway, 95 South in VA, when sunroof blew out. No traffic in front at the time, nothing hit the car. Driving around 65 mph. Temp outside was ~85-87, AC in car at 74. Just blew up and out after a large "Bang". There was no impact to the vehicle prior and no other marks or scratches to the vehicle indication an impact.

The 2017 Hyundai Santa Fe was brought to dealership on 3/27/26 for an oil change and a computer update was completed for Emissions Improvement. Upon picking the vehicle up after service, it was noticeable that it was not shifting correctly. I spoke to the service department and asked if the memory was cleared with the update an if it was having to relearn how I drive and the said it should not be affected. This went on for a few days and I left the car with them to duplicate as there were3 no stored codes. After a few weeks, the Teck Line recommended a new transmission, which Hyundai offered goodwill assistance. As we were waiting for the transmission to arrive from being on backorder, a bulletin for Service Campaign 9C2 was release on 5/18/26 that described my experience with shifting issue almost exactly. The transmission was replaced and the drivability issues still persist. Hyundai says that I must let my car warm up for 1-3 minutes to allow a catalyst to reach temperature and not cause rough shifting. This rough shifting is the effect of the update and thus te reason that my transmission needed to be replaced. Further investigation showed that this update is a known issue and cannot be reversed once installed. Currently, I must start my car in 90 degree weather to warm it up as a result of this update which is not logical in any thought process. I have asked Hyundai to cover the balance of the new transmission as this is a result of thier faulty software update with no success.

A Hyundai recall 9C2 update was applied to my vehicle. Ever since that update my vehicle hard shifts on cold starts which I fear is damaging the transmission. Hyundai dealer was able to replicate this and keeps advising us that concern is ‘under review with Hyundai’. I have the service order that states this. This problem has been ongoing for Months! I think Hyundai needs to find a resolution to this as my research indicates it is impacting a lot of customers.

On June 10, 2024 at 107,129 miles Hertrich Hyundai dealership of New Castle inspected my vehicle and submitted a request to Hyundai for engine replacement under the recall settlement of the Theta II Engine Settlement. Hyundai denied the request because of the rebuilt title, even though the rebuilt title resulted only from prior Roof damage unrelated to the engine, powertrain, or recall issue. After continuing to seek assistance from Hyundai, my engine ultimately seized and suddenly stopped working on May 10, 2026, while driving on the highway with my two children. The vehicle lost power and stopped in traffic, creating a dangerous situation and causing my children extreme fear and distress. Had Hyundai honored the Theta II Engine Settlement when I first requested assistance, this failure could have been prevented. I request that Hyundai honor the Theta II Engine Settlement and replace my defective engine at no cost to avoid any future problems. My Hyundai Santa Fe is covered under the Theta II Engine Settlement. For over three years, I repeatedly contacted Hyundai after experiencing symptoms consistent with the known Theta II engine defect. Hyundai failed to provide meaningful assistance, did not properly process my requests, and denied coverage solely because of the vehicle’s rebuilt title.

The 9C2 campaign software update introduced dangerous vehicle hesitation and unpredictable gear changes in active traffic, presenting and immediate crash hazard

I own a 2017 Hyundai Santa Fe Sport 2.4L (VIN: [XXX]). On XXX, my vehicle received Campaign 9C2 (ECU software update for Theta II emissions improvement). Shortly after this update, I began experiencing a drivability issue that did not exist beforehand. Description of the issue: The problem occurs only after the vehicle has been sitting long enough for the engine to become completely cold, typically overnight. During approximately the first 1/4 mile of driving, the vehicle intermittently jumps, surges, or lurches while accelerating normally. Once the engine warms up, the symptom completely disappears and the vehicle drives normally for the remainder of the trip. There are no warning lights, no check engine light, and no diagnostic messages. The Hyundai dealer has had the vehicle for nearly a week but has been unable to reproduce the concern. Because the issue only occurs during the initial cold start and first portion of the drive, I am concerned that it may not have been tested under the same conditions in which I consistently experience the problem. I am not claiming that Campaign 9C2 caused the issue, but the timing is notable because the symptom began only after the ECU update was performed. I am requesting Hyundai's assistance in determining whether: - the ECU update was installed correctly, - any required adaptation or relearn procedure is incomplete, - there are any related Technical Service Bulletins or software updates, or - additional diagnostics should be performed during a true cold-start drive with live data recording. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

On July 4, 2026, I was driving 2.5 hours from home. My car stopped after about an hour of travel. The car shook and the check engine light came on as the car shut down. There were no warning lights on in my vehicle. I have oil change records. My car had burned through all the oil in an hour. This is not a new problem with this model Hyundai. Every group I went to discuss the problem online all had customers who reported their vehicles suddenly started burning oil quickly which resulted in damaged motor with no warning lights in the dashboard. I had to have my car towed from out of town to the dealership. The dealership that said I had extended warranty on parts of the motor. However upon checking the motor, they said it wasn't covered. I filled out a claims report with Hyundai motors who looked into the problem and also said it's not covered under warranty. This is a known issue of Hyundai with a failure to warn of low oil in the car's warning center. This is a fault of Hyundai. I've taken good care of my car and just paid $1000 for new tires on July 2, 2026 before my trip. The dealership quoted me a price of $3500 to replace the motor with a used one. It would also require 16 hours of labor which I Believe is $200 an hour. I believe they should replace the motor due to faulty systems. My car has 107,000 miles on it, but whenever I've gone to have it checked out, everything checked out fine even at the dealership. Also, this is a known issue that Hyundai is refusing to address with their customers.

After having the Service Campaign 9C2 ECU SOFTWARE UPDATE FOR THETA II EMISSIONS IMPROVEMENT, TSB 26-01-013H-2 done, my vehicle started having driveablity issues. On a normal, cold start the engine's RPMs go up really high, so I take my foot of the gas and the revs drop, almost stalling the car, and then the car bucks. I put my foot back on the gas pedal, and the engine revs really high again and takes off. If I try to drive normally, the car bucks and runs rough. My car also revs a lot higher during highway driving, than it did before the update. All of this is also causing terrible gas mileage. My car did nothing like this until I had the 9C2 update.