2018 Hyundai Sonata: multiple warning lights

Filed Aug 3, 2025 · Electrical, Engine · NM

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

Filed Jun 10, 2025 · Acceleration, Electrical · OH

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.

Filed Mar 8, 2024 · Electrical, Engine · MD

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)

Filed Dec 26, 2023 · Electrical, Engine · PA

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.

Filed Jun 5, 2021 · Engine · PA

6/5/21 2018 Hyundai Sonata - less than 20K miles Turning left into parking lot at very low speed Car completely lost all power and brakes - all dashboard lights etc went out No warning of any kind - nothing evenly remotely like this has happened before Was able to glide into parking spot and stop but only with extreme pressure on brake Key was still in on position - put car in park, set parking brake, turned key to off Car started again and was able to drive about 1/4 mile back home Immediately called dealer from whom we purchased and had car towed No diagnosis as of yet

Filed Dec 22, 2019 · Electrical, Engine · 9,500 miles · NY

My 2018 sonata will not start when temp drops below 20 deg f. It has happened 3 times this winter and when it warms back up to 40 to 50 degree it will start. When I turn the key on all the lights on the dash light up like normal. I can move hear selector and turn wheel. But the starter will not engage nothing is heard not a click or a shirt. Is this common problem?

Filed Aug 10, 2019 · Brakes, Electrical · 19,725 miles · TX

"multiple warning lights are coming on the dash for ABS failure."cause: 5891r00 hydraulic module assembly replaced. "scan test codes c1741, c2402, c1360 diag system. Line case number 2019080600434 perform voltage and ground test per tech line found ABS hydraulic unit internal failure, replaced ABS hydraulic unit, perform all calibrations and variant coding clear codes, reset adaptives. Problems of yellow light coming on on dash was during accelerations and turning cruise control on