Power Train owner reports: Hyundai Sonata years in the records

The records describe a problem worth checking before purchase.

“The primary failure is in the Engine/Powertrain system and Knock Sensor Detection System (KSDS), causing 6 identical sudden engine stalls (OBD-II code P1326) from 09/2000 to 06/2026. Additionally, severe excessive oil consumption was documented during 2 of these diagnostic visits, showing deep-seated engine issues. The vehicle and all records are available for inspection at the Hyundai dealer. Safety was severely threatened on 6 occasions. The vehicle abruptly stalled at 60+ mph in active highway traffic, forcing an immediate engine shutdown. This left me with highly impaired steering and braking control in fast-moving traffic, creating an imminent risk of high-speed rear-end collisions and jeopardizing my life and others. The primary stalling defect and P1326 code were confirmed 6 separate times by the authorized Hyundai dealership. The secondary excessive oil consumption issue was also formally confirmed by the dealer during 2 of those visits. Despite multiple dealership-confirmed diagnoses, no permanent repair has been achieved. The vehicle has been inspected during all 6 visits by dealership technicians. For the current (6th) visit, the dealer could not resolve the recurring defect and formally contacted Hyundai Corporate Technical Support for expert analysis, which is currently ongoing. Except for the first visit, the pattern is identical: the car stalls, the dealer clears codes/replaces KSDS, and it stalls again within 3 weeks. Notably, during the 4th visit, they replaced the Intake Manifold. Now, on this 6th visit, they demand I pay to replace that same part again. This proves they cannot diagnose the root engine failure and are only applying useless, temporary fixes. Prior to all 6 stalls, the flashing Check Engine / Hybrid Warning light triggered on the dashboard. This critical KSDS alert was followed within seconds by a total loss of motive power. Also, a history of rapid engine oil depletion and low-oil alerts was documented in 2 of the diagnostics.”

The records describe a problem worth checking before purchase.

“2019 Hyundai Sonata Sport. (Original owner). Problem: Transmission. [XXX] (9,912 miles). Lack of power, vehicle did not move when trying to merge onto freeway. Very unsafe. Also, hesitation and jerking. [XXX] (10,619 miles). Lack of power, hesitation, jerking. Hyundai tech performed TSB, TCU updates, ECU update for knock sensor performance, reset engine & transmission updates. [XXX] (41,332 miles). Harsh shifts, hesitation, jerking, clunk sound, gear grabs, bursts of power, lack of power. Unsafe to drive. February 2, 2026 (41,751 miles). Hyundai tech found leak at case seal. Hyundai replaced transmission. [XXX] rough start, vibration in pedals. March 9, 2026 Hyundai tech found transmission fluid leak at case seal. Hyundai replaced transmission. March 25, 2026 Hyundai service advisor voicemail said, have to submit to Hyundai another transmission replacement because new transmission is not good. Issues shifting in reverse, hard slams, loses gears. [XXX] picked up vehicle from Hyundai service dept. Harsh shifting, hesitation, jerking, clunk sound, gear grabs, bursts of power. Clunk sound in steering wheel when turned back-and-forth. Front end vibration & wobbly. Vehicle unsafe. May 26, 2026. I notified Hyundai Motor America. Case #[XXX]. June 10, 2026 (43,000 miles). Hyundai service dept. informed me of right and left front axle replacement, universal steering joint replacement. Vehicle unsafe. [XXX] (43,000 miles). Test drove car with Hyundai tech. Verified front end vibration & shaking. Vehicle unsafe to drive. Hyundai service manager said that Hyundai should recall the transmissions. To date, my car is still at Hyundai service dept. Hyundai's service manager said that the Hyundai service dept. will have a meeting regarding my car and include Hyundai's service director, etc. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)”

The records describe a problem worth checking before purchase.

“For the past several years, this vehicle has experienced a recurring and unresolved engine malfunction that creates a safety hazard. The problem manifests as follows: Symptoms when check engine light illuminates: • Idle RPM elevation to approximately 1500 RPM (normal idle: 800 RPM) • Sudden unintended forward acceleration when foot is removed from brake pedal • Significantly reduced acceleration performance during normal driving • Vehicle becomes difficult to control safely The malfunction occurs intermittently but follows a consistent pattern. This is not an isolated incident but a recurring defect that has persisted for years. Multiple diagnostic and repair attempts have been unsuccessful: • Coconut Creek Hyundai service center - unable to diagnose [DATE(S)] • Independent mechanics - unable to resolve [DATE(S)] • Issue remains unresolved despite multiple service visits Despite multiple attempts by qualified technicians, the root cause has not been identified and the defect has not been corrected. This malfunction creates a significant safety hazard: • Unintended acceleration increases risk of collision • Reduced acceleration capability limits ability to merge or accelerate safely • Check engine light indicates undiagnosed system failure • Problem is intermittent and unpredictable, making it unsafe to drive I am concerned this may represent a defect pattern affecting multiple 2019 Sonata vehicles. NHTSA should: 1. Investigate whether this represents a defect pattern in 2019 Hyundai Sonata vehicles 2. Determine if a safety recall is warranted 3. Contact Hyundai Motor America to address this systemic issue”