product.specifications
specs.g_fuel_economy
specs.city_mpg23
specs.highway_mpg33
specs.combined_mpg27
specs.annual_fuel_cost$2200
specs.ghg_score5 / 10
specs.g_engine_drivetrain
specs.engine_size2.5 L
specs.cylinders4
specs.fuel_typeRegular Gasoline
specs.transmissionAutomatic (AM-S8)
specs.drivetrainFront-Wheel Drive
CO₂335 g/mi
specs.g_classification
specs.vehicle_classLarge Cars
specs.data_sourced_from FuelEconomy.gov (specs.energy_dept)
product.complaints_section83 total
HYUNDAI SONATA 2023 POWER TRAIN
mediumThe contact owns a 2023 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the transmission shifted into neutral(N) and failed to shift into park or drive on three occasions. The vehicle was restarted. After restarting the vehicle, the vehicle was shifted into drive, and the contact continued driving. The message that the vehicle could not be shifted into other gears was displayed. The vehicle was originally purchased in another state. The vehicle was taken to the local dealer to be diagnosed. The dealer determined that the battery and fuel injector pump needed to be replaced. The vehicle was repaired; however, the failure recurred. The manufacturer was not contacted regarding the failure. The failure mileage was approximately 50.
HYUNDAI SONATA 2023 FUEL/PROPULSION SYSTEM
highWas driving and stopped at a stoplight. When I went to drive it started sputtering and if I wouldnât have driven into a gas station, it wouldâve given out in the middle of the road. It wouldnât let me switch to drive or reverse , only neutral or park. It threw a code P0301, cylinder 1 misfire. Had to get it towed. Now I have to get my spark plugs and fuel injectors replaced.
HYUNDAI SONATA 2023 ENGINE AND ENGINE COOLING
mediumThe contact owns a 2023 Hyundai Sonata. The contact stated that while his wife was driving at an undisclosed speed, the message "Engine Overheated" displayed. The contact checked the Hyundai app, but it showed no failure. The contact's wife drove to their son's residence, who inspected and discovered that there was no coolant in the engine. The contact's son added coolant to the engine. The vehicle was taken to the dealer, who replaced the coolant valve, exhaust muffler assembly center, clamp assembly exhaust pipe, two gasket exhaust pipes, and added coolant. The contact related the failure to Technical Service Bulletin: 23-EM-009H (EHRS Coolant Leak Repair); however, the vehicle was not covered under the TSB. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 18,500.
HYUNDAI SONATA 2023 ENGINE AND ENGINE COOLING
lowSee attached document for complaint.
HYUNDAI SONATA 2023 ENGINE
mediumThis is an extremely common issue plaguing Hyundai & Kia vehicles with the Theta III 2.5L Turbo engine, Such as Kia K5 GT, Hyundai Sante Fe, Hyundai Santa Cruz, & Hyundai Sonata N-Line. Its a failing ITM (integrated thermal management) unit or otherwise known as an ITMS unit. There is a rod within the ITM that prevents proper control of the flow of cooling the oil and engine coolant of the engine. Results in Cooling issues, such as a cold lower radiator hose while the engine is hot, or 'limp mode' during acceleration, that causes a sudden loss of power while trying to merge on the expressway. There has been other Kia models and years that have had TSB's related to fixing this issue, but Hyundai has released nothing. I have uploaded an example of one of the TSB's that do not apply to my car. Technical symptoms often include: Fans running 100% full duty (high) while the lower radiator hose stays cool. Or Fuel dilution or a 'rich' running engine. Because the engine is overcooling that keeps the car's fueling rich and in a open loop mode affecting emissions and contaminating oil. Personal Details of exactly what happened when i noticed mine was failing. I ran home on my lunch break, and while accelerating on a ramp to get up on a highway, my car started beeping and flashing "Engine Overheated" and i immediately let off the gas with preparation to pull over. The second i left off the gas, the coolant temp within 1-2 seconds went from a little over 3/4 the way up the gauge back to normal a little below half temp. I resumed driving a 3 mile drive back to work, with it showing normal temps the rest of the way. I popped the hood when i got to work to see if coolant was low, and it was completely normal, a little over halfway between the min/max lines. The car continues to run hot, often with the cooling fans running at 100%.
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product.status_history
status.certified→status.safe1 Jun 2026
Lemon Score: 88. 12 data points. v3 scoring.
status.uncertain→status.certified27 May 2026
Lemon Score: 100. 0 data points. v3 scoring.