2018 Hyundai Sonata: adaptive cruise control problems

Filed Aug 16, 2025 · Brakes, Driver assistance · IL

About a year and half ago, a lot of my engine trouble lights turned on while driving. It was sleeting at that time when the lights turned on and they're still on today. I paid to have the Hyundai dealer to check it out soon after the trouble lights first turned on. They diagnosed the problem as a faulty HECU. I would have had them replace this, but they estimated it would cost about $3800 to fix. This HECU malfunction is causing the following issues: ABS does not work, traction control does not work, forward collision prevention does not work, brake auto hold does not work, cruise control does not work probably because it can't auto brake any more. I've had some scary times driving and trying to stop when the roads have been wet or snowy.

Filed Jul 15, 2025 · Driver assistance · IA

When starting car warning lights came on for ABS, AEB, Cruise Control. Cruise control is locked out and not working due to these warnings.

Filed Jan 9, 2020 · 26,000 miles · OH

I was driving on an open interstate using smart cruise control when a message popped up on the dash screen: smart cruise control disabled. Radar blocked. Weather conditions were dry and my car was clean. There had been no snow accumulation in my area nor any in the area in which I was driving. There were a few cars around. The car that was in front of me made an exit about a minute after the message and indicator lights appeared. The message and indicator lights returned to normal after about 5 minutes. An hour and a half later, the same message and indicator lights appeared. The sky was darker with a few flurries in the air but no accumulation. I turned off smart cruise to finish the trip. I did not experience any problems with smart cruise on the 5 hour return trip. Weather conditions then were gray and raining. The trip is mostly interstate but the destination is mountainous. I made the trip several times over the last 3 years with no problems.

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

Filed Jan 22, 2019 · Engine · 17,000 miles · TN

I had an oil change on friday 1/18/2019 the next day I'm driving on the interstate using cruise control and my car cut my cruise control off and the check engine light started flashing and my car would not go over 20mph even with the pedal all the way down to the floor. The screen in my car popped up a message that said the engine control system had some type of failure. 2 days in at the dealership and no one knows what the problem is. It's not even a year old, idles fairly hard, and now won't accelerate.

Filed Jun 1, 2018 · Acceleration, Brakes · 400 miles · IL

Tl* the contact owns a 2018 hyundai sonata. While operating the vehicle, the automatic emergency braking system malfunctioned. On several occasions, the vehicle failed to automatically stop when a second vehicle was present. The failure occurred while driving in reverse and while driving at highway speeds with the cruise control activated. The vehicle was taken to napleton hyundai glenview (1620 waukegan rd., glenview, il) and the contact was informed that the failure was normal. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 400. *tt consumer stated braking works when car has cruise control activated, when relying in "aeb" nothing happens. Vehicle purchase date should be on or before incident date updated 9/21/18