Electrical System owner reports: Hyundai Elantra years in the records

The records describe a problem worth checking before purchase.

“Initial Fault Code: P0303 Replaced all 4 spark plugs and all 4 ignition coils. The check engine light extinguished momentarily but returned, logging P0303 and a new P0301 Replaced all 4 fuel injectors. CEL extinguished momentarily and then returned, logging P0303. Replaced the entire engine electrical harness. Concurrently, all related electrical components and connectors were meticulously cleaned with professional contact cleaner. CEL extinguished for significantly longer period of time, and then returned, re-logging P0303 and P0301. Thid suggested the ECU was "handshaking" with new components but re-logging the fault upon detecting the persistent core issue. A full compression test was performed. All cylinders reported results within specification. Using a borescope I inspected cylinder walls in piston tops. There was significant carbon residue buildup but nothing out of the ordinary for similar GDI engines. I still performed a PEA GDI specific chemical cleaning. It was a a little smoother afterwards, but the misfire persisted and CEL remained on. I also removed, cleaned, and tested common sensor faults, with no result. Also p0128 code and no start / electrical drain, and engine light started flashing numerous occasions had to stop the vehicle. I tried swapping the coils, but all that proved was that the coil was good, I did a power and ground test, it passed the connector had 12 plus volt power and a perfect resistance to static ground. The signal wire from the coil connector had perfect continuity to the ECU but had OL to chassis ground showing there was no short. A test light was used to see if anything was coming from the signal wire to the ignition coil and that test failed, there was no signal pulse. The diagnostic process has definitively proven a component-level failure inside the engine control unit. See attached file for more detailed information.”

The records describe a problem worth checking before purchase.

“This vehicle lacks an engine immobilizer, a defect that has made 2011-2022 Hyundai and Kia vehicles unusually susceptible to theft via a method widely publicized on social media as the "Kia Challenge." My vehicle was stolen using this method, driven approximately 30-40 miles, and abandoned. It was found stripped of parts, including the catalytic converter. This defect is already the subject of a nationwide class-action settlement (hyundaitheftsettlement.com) and a multistate Attorney General settlement. I am filing this report to ensure my vehicle/incident is included in NHTSA's records on this ongoing safety issue.”

The records describe a problem worth checking before purchase.

“Alarming rate of oil consumption causes sudden loss of power / acceleration which definitely increases probably of causing an accident. Local repair shop confirmed extremely low oil level with no evidence of where oil went shortly after oil change and annual safety inspection. All the dashboard warning lights came on when it happened but low oil warning light came on prior to event. No warning whatsoever, just sudden loss of power and completely lit up dashboard.”

The records describe a problem worth checking before purchase.

“I am writing to formally report a safety concern regarding my 2018 Hyundai Elantra. The vehicle has experienced a failure of the heater hose/pipe, which appears to be made of plastic and connected to a metal component. This failure has resulted in a coolant leak, creating a serious risk of engine overheating. This issue is not only inconvenient but also dangerous. A sudden loss of coolant while driving can cause the engine to overheat without warning, potentially leading to engine failure, loss of vehicle control, or leaving the driver stranded in unsafe conditions. This is especially concerning while driving on busy roads or highways. Based on my experience and discussions with repair professionals, this appears to be a known issue with this model, as the part is not widely available outside of Hyundai/Kia and may indicate a design flaw. A critical cooling system component should not fail prematurely under normal driving conditions. Given the safety risks associated with this defect, I believe this issue warrants further investigation and consideration for a recall or extended warranty coverage. Consumers should not be responsible for costly repairs caused by a potentially defective design. I respectfully request that Hyundai review this issue and provide assistance with the repair, as well as take appropriate action to ensure the safety and reliability of affected vehicles. Sincerely, [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)”