Hyundai Santa Fe jerking problems

Filed Oct 25, 2026 · Engine · CA

Hyundai Dealership, Pedder Hyundai of Poway, applied recall 9C2 to 2020 Santa Fe on 10/20/2026. Vehicle idle is now rough at startup and gas pedal angle no longer is reliable for controlling vehicle speed. Engine surges and jerks during initial operation on residential street due to software change. The vehicle did not operate in this manner for the last six years. I never felt like I had erratic engine control due to gas pedal response. I would like this recall removed and the original software re-applied, or my car bought back by Hyundai.

Filed Oct 5, 2026 · Transmission · MT

Driving at highway speed, vehicle stuttered/lurched. The check AWD, engine light, tire pressure warning lights came on. Check by mechanic resulted in error code P0741 (Torque Converter Clutch Circuit Performance or Stuck Off). Search of error code P0741 indicates that there is a Technical Service Bulletin TSB-23-AT-005H regarding this KNOWN problem. A stutter or lurch of the vehicle can cause the driver to over react, stop or swerve suddenly in traffic potentially causing an accident not to mention possible being struck on the side of the road while waiting for a tow/service truck. Vehicle/components have not been checked by manufacturer--only diagnostic code by Mechanic. Warning lights after incident included the AWD system, Check Engine Light, and Tire Pressure sensor light. Vehicle is being towed to a Hyundai Dealership as Mechanic advised it is not safe to drive.

Filed Sep 27, 2026 · Engine, Transmission · MD

Immediately following the mandatory Hyundai Servie Campaign Update 9C2-ECU THETA 11my vehicle began exhibiting severe hesitation, very rough idling, jerking at slow speeds and when gear changes, difficulty going up inclines and almost feel at times as though it is about to lose power which poses life threatening situations especially when turning into traffic. I have reported it to the dealers who never once test drove the vehicle but said to me that they did and could find no problem, however they did make me pay for repairs which never fixed the problem. I returned three times with the same issue. They recommended a Fuel Induction Service and a Auto Trans Service. Spark plug change. Igniton coils change. Nothing worked!

Filed Sep 23, 2026 · Engine, Transmission · TX

On 03/26/2026, my 2019 Hyundai Santa Fe received Hyundai Service Campaign 9C2 (TSB 26-01-013H-1), which included an Engine Control Module (ECM) software update for Theta II emissions improvement. The vehicle did not have the following drivability problem before this software update. Immediately after the 9C2 update, the vehicle began jerking/bucking slightly at low speeds, most noticeably around 10-20 mph when coasting with no accelerator input or when applying very light throttle. Acceleration response also feels slower than before the update, with noticeable hesitation when the accelerator is pressed. The problem is most noticeable during the beginning of a drive when the vehicle is cold. After driving for some time and the vehicle warms up, the symptoms improve, although the change in drivability remains noticeable compared with operation before the update. There have been no warning lights or warning messages associated with the problem. The issue began immediately following the ECM software update. The vehicle has not yet been returned to the dealer for diagnosis or confirmation and is available for inspection. I am concerned about the safety implications of delayed or unpredictable acceleration response, particularly when entering traffic, crossing an intersection, or merging when timely acceleration may be necessary. I am reporting this because the condition began only after Hyundai Service Campaign 9C2 was performed and I believe the federal safety agency should evaluate whether this ECM software update is causing similar drivability and acceleration problems in affected vehicles.

Filed Sep 10, 2026 · Engine · IL

At approximately 122,000 miles, my 2020 Hyundai Santa Fe experienced a serious engine malfunction while I was driving on the highway. The check engine light suddenly illuminated and the vehicle began thrusting/jerking forward unexpectedly. We immediately took action to exit the highway and were able to get off the highway, but the engine died before we could fully stop the vehicle. This created a serious safety risk because the unexpected jerking and subsequent loss of engine power occurred while traveling at highway speeds and could have resulted in loss of control or a collision. The vehicle was towed to a local independent mechanic. After inspecting it, the mechanic stated that the engine needed to be replaced and recommended taking it to a Hyundai dealership because of the continuing issues associated with the Theta II engine. The vehicle was then towed to the Hyundai dealership. The Hyundai dealership inspected the vehicle and determined that cylinders 2 and 4 were not firing and recommended replacing the valve shaft. We requested a complete engine replacement. Hyundai initially offered a 50/50 split of the repair cost, but after we requested an engine replacement, Hyundai declined and instead offered a 70/30 cost split. There was also a previous documented concern regarding increased oil consumption, as noted in an earlier oil-consumption report. The vehicle has been inspected by both an independent mechanic and a Hyundai dealership. The vehicle and engine components are available for inspection upon request. No police or insurance inspection was performed, to my knowledge.

Filed Sep 9, 2026 · Acceleration, Engine · NE

Vehicle was brought to an authorized dealership for service, and while there Campaign 9C2 (ECU Software Update for Theta II Emissions Improvement) was performed. Immediately following this software update, the vehicle developed drivability degradation, specifically engine stutter/hesitation and rough transmission shifting during cold starts. When attempting to accelerate in the first few minutes of driving, the vehicle delays engagement and then suddenly surges or lurches forward unpredictably. This creates a safety hazard, as the unpredictable power delivery and lag prevent the vehicle from accelerating safely when merging into traffic or turning across oncoming lanes, placing occupants at an immediate risk of a collision. The software logic error is fully reproducible every time the vehicle has sat long enough to cool down. The dealership confirmed the update was applied. There were no warning lamps or symptoms prior to the 9C2 update; the failure was caused directly by the manufacturer's campaign software modification to the Engine Control Unit (ECU). The vehicle and its ECU are available for inspection upon request.

Filed Sep 9, 2026 · Brakes · NY

Despite having the DCT software recall repaired, today the parking brake disengaged after the car was idling for a few minutes at my son’s school. It lurched forward, startling me, and then I was alerted that the emergency parking brake deployed. The rollaway could have injured a child in the parking lot. No alerts or lights have been on prior. Additionally, after the rollaway incident, I was stopped at a red light, and my brakes depressed halfway. The last few weeks the acceleration from stop is difficult, and the brakes shudder and partially depress, especially when driving over a bump - feeling every minor flaw in the road rattling beneath my foot on the pedal. To also be mentioned - I have retained an attorney to pursue a Magnusson Moss cash & keep settlement on the car. From June - August 2026 the car was out of service, 4 repair orders, 2 dealerships, and a FSE I demanded finally found & diagnosed faulty O-rings causing the freon to leak and the AC to fail. The car also smelled strongly of fuel one full day, and the dash & steering wheel felt hot to the touch - but no defect was found or diagnosed.

Filed Aug 31, 2026 · Electrical, Engine · NC

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.

Filed Aug 28, 2026 · Engine, Fuel system · WI

My vehicle recently received the Hyundai 9c2 emissions upgrade they required and since then the vehicle has had predictable acceleration issues for the first several minutes after the vehicle. While trying to slowly accelerate the vehicle with unpredictably lurch forward. Many people have been reporting this.

Filed Aug 24, 2026 · Electrical, Engine · NJ

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.