2018 Hyundai Sonata electrical problems

ELECTRICAL SYSTEM

We think there’s an issue with the abs module and wheel speed sensor because we started having a problem where the brakes wouldn’t work or would stutter. The car would shake real bad it would make an awful grinding sound but normally only when trying to stop at higher speeds or long braking. The only thing that made it stop was to unplug the abs but then other parts of the car stopped working like the speedometer and the sensors around the car. So we got the abs replaced but the new one started doing the same thing. We did some research and it sounds like the same issue Hyundai is having with the palisade. The incident that made us get it replaced to begin with was were driving down the road and we got to a traffic light but when we tried to brake they just didn’t work so we drove through the red light luckily the one person who was supposed to be going saw us and didn’t pull out in front of us so we didn’t get hit. We haven’t taken it to the dealership yet but my sister who teaches automotive repair at the community college is the one who diagnosed it so she said we should report it here so maybe it won’t happen to anyone else. Before we had the brake issue we were having problems with basically everything on the dash not working randomly. We’d be driving down the road and the speedometer and the outside sensors and the gas gauge and the traction control all would go out at the same time it’s the same stuff that went out when we had the abs unplugged so it seems that might be related.

NHTSA complaint #11732415 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

To Whom It May Concern, My name is [XXX] , and I am formally escalating serious ongoing issues with my 2018 Hyundai Sonata. Despite repeated attempts to resolve these concerns through the dealership, my vehicle continues to experience excessive oil consumption, engine failures, and additional mechanical issues, all while under warranty. I am now seeking immediate corporate intervention. Timeline of Events and Mismanagement: •2024(~62000 miles): First reported oil leak and excessive oil consumption. Directed to complete multiple 1,000-mile oil consumption tests. I complied fully. •2024: Repeatedly redirected between service advisors, received conflicting instructions, misleading guidance, and poor communication. No effective resolution was provided. •2025: Completed extensive additional diagnostic testing as requested. Despite full compliance, no clear corrective action was taken. •2024–Present: Vehicle brought to Hyundai on US 19 in New Port Richey approximately 13–15 times for engine-related concerns. Each visit demonstrated neglect, miscommunication, and failure to properly address documented issues. •February 11, 2026: After proper diagnostics, vehicle found to have two additional oil leaks, including a head gasket and valve cover requiring replacement, with total estimated repair costs exceeding $3,000. I was advised I must repeat all testing already completed in 2024 before final determination. •Vehicle is currently at 71,332 miles. Impact: •Delays and repeated unnecessary testing pushed my vehicle beyond warranty limits. •Mismanagement caused significant financial burden, emotional stress, and frustration. •If initial oil consumption issues had been properly addressed under warranty, the current extensive engine failures could likely have been avoided. Immediate Requests: 1Full review of my complete service and diagnostic history. 2Warranty or goodwill coverage for all necessary engine repairs, including head gasket and valve cover INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.

NHTSA complaint #11718006 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Intermittent no-crank, no-start condition. Dash lights illuminate, push-button start produces no response. Brake pedal applied. Vehicle becomes immobilized without warning. I’ve been stranded on multiple occasions. Unable to commute to work, or home. Most recently on December 19,2025 the car completely shut off while driving on the highway.

NHTSA complaint #11707411 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Unknown. 2018 Hyundai Sonata engine has failed. Only purchased the vehicle in December 2024, and the engine is defective. There is much information, via research, indicating that Hyundai is aware of the engine issues with this year vehicle, but are unwilling to make amends. Vehicle has 100,189 miles.

NHTSA complaint #11697623 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Oil consumption was ridiculously high, changing oil/topping off oil constantly. Car would not accelerate over 30 mph without sputtering and rumbling. I had mechanic diagnose bad sparks plugs due to sitting in oil from leaking. After I had them repaired/replaced the car drove great for 1 day, then decided to die in the middle of a busy intersection while I had my teenage son in the car with me. My son and I had to PUSH it out of the busy intersection onto a side street to get out of the way! I had it towed to Hyundai dealer who said the spark plugs were bad and that the fuel pressure sensor and gdi pump were faulty and needed replacement. Left front lower control arm/ball joint assembly also requires fix. To the tune of $3000 + . It’s been at dealer for past few months until I can afford the repairs including the 2nd diagnostic and tow it took to get it to dealership.

NHTSA complaint #11689709 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM:INSTRUMENT PANEL:SPEEDOMETER/ODOMETER

Odometer Fraud. The contact purchased a 2018 Hyundai Sonata. The contact discovered a mileage discrepancy while searching the vehicle history report. The contact stated that the odometer indicated several readings. The vehicle was a dealer sale. The contact was unaware that at the time of purchase, the vehicle mileage was 148,000. The contact stated that the mileage on the Title was blank, and the mileage on the registration was 75,519.

NHTSA complaint #11686923 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

I first noticed that my vehicle was consuming an excessive amount of motor oil, with the oil change light coming on every 1,500–2,000 miles. I routinely had to add oil between changes to keep it running. On May 30th, while driving on surface roads, I heard clanking noises from the engine. When accelerating, the vehicle clanked heavily, and then went into “limp mode,” limiting acceleration to about 10 MPH before struggling up to 30 MPH. I added oil, but a local shop diagnosed it with code P1326 (knock sensor) and advised that Hyundai engines are prone to failure around 100,000 miles and that I should take it to the dealer for warranty evaluation. I contacted Graham Hyundai, who told me they could not see the vehicle until July 1st and that I would be responsible for towing. I dropped the vehicle off on July 1st, but it was not inspected until July 8th or 9th. I was later told Hyundai was being consulted. Around July 15th–16th, the dealership informed me that I would need $1,500 in repairs. They stated the engine had passed the Hyundai Bearing Clearance Test (a $350 charge) and that Hyundai required me to pay for an ECU “KSD logic” upgrade ($175). They also stated the engine valve cover was leaking, requiring new spark plugs, for a total of $532. Additional charges included an oil change and other shop fees and taxes. After repairs, I was instructed to drive 1,000 miles and then return for an oil consumption test. After approximately 1,000 miles and four weeks, the dipstick check showed the vehicle had consumed nearly all of its oil. I was then told I now need a combustion chamber cleaning, costing approximately $850 and requiring three days in the shop. Given the oil consumption issues, repeated engine warnings, limp mode incident, and the significant costs already incurred for testing and required upgrades, I am requesting that my engine be replaced under warranty and that all fees I have already paid be reimbursed. Rather than keep paying for work.

NHTSA complaint #11681369 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

car turned off at light all lights work and turns on engine won’t roll over the battery and alternator and starter are all good

NHTSA complaint #11678065 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

On 05/27/2025, my rear back-up camera started to malfunction. Last week my dash started to malfunction electronically. When I would start my vehicle, all of the lights would start to turn on and stay on on my dash. My speedometer would not move while I was driving, so I could not see how fast I was going. I believe this is a severe safety issue for myself as well as others. The tachometer would jump up and down and would not function correctly. My dash stated that I had low tire pressure, that I was having problems with my traction control, that my BSD system was not working, that my ABS was not working, that my emergency brake was on even though it was not. It also stated that I did have functioning air bags, which is a severe safety hazard in the chance that I could've gotten into a wreck and they might not have worked. It also stated that I was not in Drive even though I clearly was. It also stated that I had no power steering while I was driving, before the light would turn off and I could properly steer again. This is a severe safety issue that could put me at risk. Finally, my check engine light turned on and stayed on. Yesterday on 06/09/2025 I was able to take it a vehicle maintenance shop so they could run a full diagnostic test. They discovered that I did not have power steering even though there was fluid due to the electrical problems with my dash. They also discovered the C-CAN buss was off and that my vehicle was losing communications with the TCM and HVAC. It was discovered that this was due to my rear view back-up camera malfunctioning, causing the C-CAN network to short out. They had to unplug my rear back-up camera to return everything to normal. I have found on hyundai recall forms that other years of hyundai models had similar problems and I believe that 2018 hyundai sonatas are also having the same problem. I wanted it to be made aware because online, people have stated they are having the same issues. Attached gif that shows part of problem.

NHTSA complaint #11666015 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

When my car suddenly stopped on the highway, I encountered an issue with the “body control module.” The car wouldn’t start, and the key fob was ineffective. Additionally, the airbags stopped working. I don’t recall all the details, but I was unsure of where to report the dangerous vehicle. I’ve noticed several other Hyundai owners complaining about this issue, where their cars suddenly stop in the middle of nowhere.

NHTSA complaint #11632977 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

43000 miles on car. original owner. new battery. car does not cold start in the morning. all electronics light up, but engine doesn't start. This is a known issue from all the posts i found online, yet Hyundai has not issued a recall. I paid 300 for a battery 2 weeks ago and the issue didn't resolve. Now i am being told by dealer it is the starter and it's not covered because my 5 yr warranty is expired (my car is 6 years old). This is a known safety issue across the 2018 Sonata line. This should be a recall or bulletin, instead I have to come up with hundreds of dollars more to replace a starter on a car with ONLY 43,000 miles.

NHTSA complaint #11628234 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The electrical and engines in these cars are horrible . The steering wheel keeps locking up while driving cause everything to flick inside the car . This is a major safety issue for me when I am driving and I am unable to control the steering wheel. Dealership claimed they don’t see the issue with the car which I am stating . The vehicle was only inspected by a mechanic and since Hyundai said they couldn’t find anything a 3rd party confirmed that this was a ongoing issue and dealership could’ve caught it but it’s cheaper the sell the car . No everything happens at once especially if I’m turning or driving under 40 mph. First appeared 15 days after I bought the vehicle I alerted the dealership immediately

NHTSA complaint #11620886 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

My 2018 Hyundai sonata with only 20,821 had to have the starter replaced on [XXX] because the car would not start. I had 3 different people including AAA road service to verify why it would not start and what the problem was. I end up having my car towed with AAA to a local mechanic shop, Mike Hepler auto repair St. Cloud Florida 34769 407-593-0152, and Mike did the diagnosis saying the starter was bad it was(fried) as he put it. He said he could replace it for $492.17 for part and labor which I accepted for him to do the job. I had left numerous messages (4)for my local Hyundai dealership service department to call me to let get a diagnosis and no one has ever called me back to give them my information or ask any questions.

NHTSA complaint #11616684 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The contact owns a 2018 Hyundai Sonata. The contact stated the trunk failed to open while using the key fob and the controllers on the interior of the vehicle. The contact had taken the vehicle to the dealer where it was diagnosed that the trunk latch had failed, and the emergency cable associated with the trunk needed to be replaced. The vehicle had not been repaired. The manufacturer was made aware of the failure and a case was opened. The failure mileage was 44,176.

NHTSA complaint #11604434 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

I own a 2018 Hyundai Sonata 2.0 turbo I paid cash for it in [XXX] with 2011 miles on it for 24,000 cash didn’t start having problems until 2022 then the I kept hearing a knocking on the left front wheel. I had it look at several places because the Hyundai of Louisville dealership kept telling me my title was branded I didn’t know what that meant till I took my title to the tag office and had the sheriffs department check the title out and it was an still is 100 % clean then my engine kept getting worse an in may of 2023 the engine stopped working I had the car towed to the local dealership and they couldn’t even look at it till Aug of 2023 the they told me I shot out a code 99 and they refused to update my software for the knock sensor system and wouldn’t honor the regular 60,000 miles warranty my car only had 48,000 miles on it . They didn’t bother telling me about the faulty GDI 2.0 turbo engine in August of 2023 I had to research it and find out on the internet that it’s a excessive oil consumption problem with this faulty engine. I had my car stolen for 6 days in April of 2023 and everything was taken out of my glove box an trunk . My oil change receipts were kept in an envelope in the glove box and were stolen with all my car registration an insurance papers . So the dealership refused my free engine replacement because I don’t have all my oil change receipts and blamed me for the oil being out of the engine which is due to the faulty GDI 2.0 turbo engine the dealership has now had my car 300 days I’ve been walking to and from my work I can’t afford a new engine all I want is me free engine replacement I have all the articles printed of all the engine problem with the cars catching on fire or just stop running period . I need some representation on having the Hyundai of Louisville Kentucky on Dixie highway to get me my free engine replacement they want 14,000$ for a new engine. I’m extremely mad and frustrated with this entire situation I have retained a lawyer. INFORMATION REDACTED PURSUANT TO THE FREEDOM O

NHTSA complaint #11577822 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Car continues to burn oil within a week of getting oil changes, the oil will be black and it will be low sometimes there will be no oil and there is not an oil leak. Right now we had to pay for a combustion test and have to drive 1,000 miles then check the oil at Hyundai again and already our oil is starting to burn and is low. Hyundai said if the combustion test comes back still burnt or low Hyundai would give me a new engine and yea it’s low and already a tint dark not as dark as it used to get but still it’s low with no leak and we did not get the promised new engine after paying almost 600$ for the test… Also electrical wise the computer randomly sounds like static when Siri talks also the music does not play and randomly the maps will close out we have tried new cords we have tried everything and it still happens.

NHTSA complaint #11577300 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

On [XXX] I was driving on [XXX] [XXX] from Rockville, Maryland when my vehicle (2018 Hyundai Sonata Limited) started to lose power and control and all dash lights started to show. I was able to move the vehicle to the highway shoulder before all power and control failed. Had I been moving at a higher speed or in heavier traffic, or been slower to react this could have led to a catastrophic incident. When the roadside assistance showed up they found that my alternator had completely detached from my vehicle. The vehicle was towed to the Sheehy Hyundai dealership in Waldorf, MD and examined on [XXX]. The maintenance staff informed me that there were 3 other similar cases they're working on, and that there is a flaw in the design of the alternator bracket using aluminum materials that failed, and that they've reported this systemic issue to the manufacturer but have yet to receive any indications that this would be considered for a recall despite the catastrophic impact this could have. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA complaint #11576236 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Car would not start. Odor of burning wires coming from the engine compartment with a little smoke. Had car towed to the Dealer who replaced the starter. Ok for two weeks then same thing. No Start and an odor of burning wires coming from the engine compartment. Had it towed to the Dealer again where it sits today.

NHTSA complaint #11569737 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

We were heading to Lakewood NJ from Bucks County (North of Philly) . Car trouble w/ hybrid system on Rt 1, just past I-95. Got off @ Fairless Hills & took back roads. We could only go 20-30 mph. IDK how many times I pulled over. Several lights on, including "Check hybrid system. Turn Engine off", engine light, low tire pressure, battery & 3 other unidentifiable lights. I turned around to try to make it home, as 2 years ago, I had a similar issue, which turned out to be the hybrid water pump failed. We finally stopped near a park & called AAA & towed to dealer. Prior to driving, we had no fluid on our driveway. My last synthetic oil change was April 19, 2023 @ 49,097mile. I now have about 57,000 miles. Today, dealer said no oil in the car & oil pan was all wet. They claim the oil filer was loose. Why would it take 8 months to loosen to lose oil? After adding oil & taking for test drive, they said the engine seized & would need to be replaced. Not under warranty. Add to complaint - the remaining dashboard lights where checked and non of them was for the oil pressure. If I lost enough oil for the engine to seize I would expect a low oil pressure light to come. The dealer informed me on Dec 26, 2023 that when doing the diagnostic, the oil pressure light came on for them. The photos attached to the case does not show the oil pressure light on.

NHTSA complaint #11561912 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

The contact owns a 2018 Hyundai Sonata. The contact stated that the vehicle failed to start in cold weather, below 50 degrees Fahrenheit. The contact stated that the vehicle would start as needed whenever the weather was warmer. The vehicle was taken to an independent mechanic, where it was diagnosed; however, the cause of the failure could not be determined. The dealer was notified of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 72,000.

NHTSA complaint #11560236 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

My 2018 sonata has been stalling out while I’m driving more so when I accelerate.I have a baby that I’m scared to drive with in the car because it does it randomly. It has been happening more & more everyday. I got new parts/starter etc. No codes on dash. Have an appointment next week with Hyundai to take a look.

NHTSA complaint #11530300 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Was driving on freeway on the way back from visiting family in different state when rpms dropped off and suddenly lost power. Car began shuddering and check engine light started blinking. Put hazards on and somehow managed to pull over to shoulder. No problems with car or anything to indicate anything was wrong before this. Called to have car towed to dealership where they said there was a software problem and it was falsely indicating low oil levels. ECM was reset and software updated for $233 which they said fixed the problem. Said that carbon deposits may have caused the software to misread and that may have been why there was no indication of problems before. Hope so because i have a long drive back.

NHTSA complaint #11517481 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

During the drive, check engine lights on then suddenly, HEV warning lights with turn off the engine with critical alert sound. I was drove again after attempting to start several times then again & again... It freaked me out when I drove on the highway, and yet to fixed & afraid to go to the dealer becase of cost & uncertain reasons. This could be big accidents on the highway.

NHTSA complaint #11514538 — an unverified report by a vehicle owner.

ELECTRICAL SYSTEM

Knocking of the engine , engine light continues flashing , lack of acceleration finally feb of this year the turbo blew up an the car stop running all symptoms of knock sensor problems . I’m Taking it to Hyundai on Dixie on Monday in two days an I hope they don’t deny the federal recall an I will have to have a loaner car . They have told me the last 5 years my title was flawed last month they denied saying that an told me my warranty was voided with 41,000 on my car

NHTSA complaint #11512498 — an unverified report by a vehicle owner.