2023 Hyundai Sonata Reliability Report

The car loses all power, the dashboard lights flash, and the engine shuts off at intersections or when shifting to Park or Reverse. Restarting is the only way to recover. Dealers often find no code, though one repair cost $1,800. Other reports describe the media screen blacking out, and a 1.6T battery that went dead after 10 days parked, which the owner blames on a stock battery too small for the drain from onboard computers. One hybrid leaks water through a door and into the trunk. Long recall repair delays also come up.

Most of these reports are about recall campaign 25V796000. Owners get the notice, but parts are not available, and some cars wait at the dealer for weeks. The underlying fault involves the gas valve or EVAP valve sticking. The fuel tank swells, a loud slam comes from under the rear floor, and the fuel gauge suddenly reads empty. Repairs include replacing the valve and updating the ECU, and one owner reports downshifting problems afterward. Another car stalled at highway speed from a failed cylinder #3 injector, and the failure came back after repair.

The emergency brake engages on its own at highway speeds of 60 to 70 mph with no vehicle ahead, which sharply slows the car and creates a rear-end risk. One owner reports it happening 3 times. The radar sensor behind the grille logo gets covered by snow and ice and stops working in bad weather. Adaptive cruise control can also react harshly when a car cuts in, braking and then downshifting and accelerating hard. Dealers show little concern.

While parking, the car surges forward without warning. That caused 2 crashes. In one, the car hit a wall, the driver broke an ankle standing on the brake, and the car was totaled. In the other, it went over a low wall into a neighbor's yard. Other reports describe hesitation and sudden loss of acceleration on the highway. The RPM rises, but the car barely reaches 40 mph. Dealers find no error code, and one responded with a 12V battery management software update.

Both reports trace steering trouble to other failures, not to the steering gear itself. In one, the engine shook and lost all power at 9500 and again at 19,000 miles, which made the car hard to steer. The dealer replaced spark plugs and cleaned cylinders without finding a root cause. In the other, cold weather knocks out power steering and every driver-assist feature at once. When steering assist suddenly returns, the car can swerve into another lane. The dealer has reproduced this fault repeatedly.

Brakes wear out unusually fast on the N Line. One owner reports 4 brake jobs, rotor replacement and resurfacing, and failed calipers by 40k miles. Replacement calipers were on back order for 2 months from Korea. The other complaint in this category actually describes a forward collision warning followed by power loss and a list of codes, with the dealer suspecting the ECM. It also mentions a 2023 Hyundai Santa Fe, so it may not apply to this car.

Rainwater gets into the rear left door, collects between the lower door seals, and pours out when the door opens. One dealer called the condition common to the model and did not attempt a fix. The owner worries that in cold climates the trapped water could freeze and keep the door from opening in an emergency. The second complaint in this category gives no details.