2017 HYUNDAI SONATA PLUG-IN HYBRID Electrical System Problems

While driving at a high rate of speed propulsion to the vehicle suddenly and without warning ceased, the electric and internal combustion engine were non-responsive (ICE stopped; hybrid motor didn't provide propulsion), the warning light said "Check Hybrid System. Turn off engine" I was put at risk because I was traveling at highway speed and was given no warning before the vehicle shut down. This has occurred nine times, I've reported all to Hyundai, they have had the car in the shop three times, the issue is not fixed. No, despite ODB2 error codes, the car has not shut down while a dealership is driving it. Yes, the vehicle has been inspected multiple times by Hyundai. Yes, always "Check Hybrid System. Turn off engine", in almost all cases the check engine light comes on after that, and in some cases additional lights such as "auto hold". This first occurred in Dec 2023, I was told the car was fixed (it wasn't) and happened again in October 2024. I haven't been able to drive my car since then.

While driving the 2017 Hyundai Sonata Plug-In Hybrid, the car will begin to stall, a rapid number of audible beeps will start, the "Check Hybrid System" notification will pop up on the dashboard, and the "Check Engine Light" appears.. The car therefore cannot be driven anymore, and I am forced to pull over to the side. In order to fix the issue temporarily, I need to turn the car off and turn it back on again. Once this is completed, both the "Check Hybrid System" and the "Check Engine Light" disappears and the car can be driven again. An OBD Scanner is unable to find exactly what is going on as the "Check Hybrid System" and the "Check Engine Light" no longer appear. This has happened 4 times now within the span of 3 months. The people at risk are me (the driver), my passengers, and potentially everyone else on the road in my nearby vicinity as the problem occurs. This problem has been confirmed by the dealer in their Hybrid vehicles. This vehicle has not been inspected yet but that is an ongoing process.

Vehicle lost power in freeway. Complete power failure. Early crashed into. Vehicle coasted to off ramp and towed away.

My 2017 Hyundai hybrid PHEV vehicle stuttered and failed to accelerate when the gas pedal was depressed and a warning light indicated a problem which was confirmed as a failed battery in January 2023. I was advised by the Hyundai Sonata service center 13 weeks ago that the vehicle was unsafe to drive due to a defective battery. They have not been able to replace the battery or provide an estimate of when the replacement battery will be delivered. The battery has a lifetime warranty but the Hyundai company and dealership is not providing a loaner vehicle or reimbursing me for rental vehicle while the unsafe vehicle sits in the service center for more than 3 months. Please help.

Problem began Dec. 2021. Has occurred on 16 occasions since then. Warning light "Check Hybrid System; Turn off Engine" comes on while driving. The car then shuts off the engine and there is a 100% loss of motive power. Sometimes is associated with very rough braking with the car "knocking'." On 3 occasions there has been partial/near complete loss of braking power. All incidents have occurred while under power, so far all while under 45 mph. No accidents yet. Two near collisions from the rear. Hyundai was notified of the problem Dec. 2021/Jan. 2022. After a month of testing they stated the car needed a new plug-in hybrid battery. One was not available and due to "supply chain issues" is still not available 15 months later. Dealership provided a loaner vehicle Jan to Sept. 2022. They requested their car back and Hyundai initially agreed to cover the cost of a rental car. I rented a car for 6 weeks in Sept.-Oct. 2022 at which point a new case manager informed me that Hyundai would not pay for a rental vehicle any longer (note: they did reimburse me the cost of those 6 weeks rental). Hyundai is well aware of the safety issues involved in driving this vehicle. However, they have chosen to ignore them. Their attorney, in a letter to the Ohio Attorney General's Office, blamed the lack of a plug in hybrid battery on supply chain issues (letter was Nov. 2022, at which time the battery was supposed to be available March 2023) and only stated that my vehicle was "drivable." Another warning message "High System Temperature; Switching to Hybrid Mode" has been occurring for a couple of years periodically. Since October 2022, the malfunction indicator lamp is always on and 99% of the time the "Check Hybrid System!" warning light also comes on after about a minute after starting the vehicle. On 3 other occasions the vehicle has entered into "limp home mode" instead of complete shutdown.

The vehicle has stalled in traffic numerous times since I bought it in 2016 creating a traffic safety issue. Without warning the lights on the dash will flash and the car dies. I have worried each time that traffic behind me would collide with my car. #1 1 1/2 years into ownership this occurred. They replaced part of the EV charging system that was overheating on the cars. (RECALL) # 2 1 /2 years into ownership the air-conditioner failed and the car stalled in traffic due the air-conditioner failing. (REPLACED UNDER EXTENDED WARRANTY) # 3 Last year I complained that a Hybrid Overheat Message would come on switching to EV mode and the transmission felt like it was slipping occasionally, and the battery only held 20 miles of charge, rated for 27. They refused to change the battery system under the lifetime warranty. #4 Last summer car stopped charging (REPLACED INVERETER UNDER EXTENDED WARRANTY) This month car stalled on the roadway, lights flashed on dashboard. Could have been rear-ended, Had to coast to a stop and restart the car. Took to dealer the said the replaced an EV computer for 5K (REPLACED COMPUTER UNDER EXTENDED WARRANTY) 3 days later same issue, stalled on busy street without warning. Took to dealer and the replaced the cars main battery, charging me $450.00 3 Days later it stalled again without warning in traffic, It's not back in the shop. THIS VEHICLE HAS MAJOR SAFETY PROBLEM. IT'S EXTREMELY DANGEROUS TO HAVE A CAR STALL IN TRAFFIC WITHOUT ANY PRE-WARNING. THE DESIGN IS DEFECTIVE. THE CARS NEED TO BE RECALLED AND BOUGHT BACK AT FULL PRICE BY THE HYUNDAI.

THIS IS THE PLUGIN HYBRID MODEL. THE LITHIUM ION BATTERY CANNOT BE CHARGED SOMETIMES DUE TO OVERHEATING CONDITION. IF THIS IS NOT FIXED, IT MIGHT CAUSE A FIRE OR EXPLOSION. SOMETIMES, IT WILL NOT LET YOU CHARGE. IT WILL NOT EVEN LET YOU TURN OFF THE CHARGE SCHEDULE TO CHARGE. SOMETIMES, IT STOPS CHARGING DUE TO THERMAL PROBLEM. HYUNDAI IS NOT TAKING RESPONSIBILITY TO FIX THIS. ATTACHED PHOTO DOCUMENTED THAT IT DID NOT ALLOW ME TO SWITCH OFF THE CHARGE SCHEDULER TO START CHARGING. I HOPE HYUNDAI WILL ADDRESS THIS PROBLEM BEFORE THE CAR BURNS UP OR EXPLODES.

Mileage: 5,000

TL* THE CONTACT OWNS A 2017 HYUNDAI SONATA HYBRID. WHILE DRIVING APPROXIMATELY 20 MPH, THE FRONT SIDE COLLISION WARNING SYSTEM FAILED TO FUNCTION. THE VEHICLE WAS TAKEN TO STEVENS CREEK HYUNDAI (4425 STEVENS CREEK BLVD, SANTA CLARA, CA 95051), BUT THE FAILURE WAS UNABLE TO BE DIAGNOSED. THE VEHICLE WAS NOT REPAIRED AND THE FAILURE RECURRED. THE MANUFACTURER WAS NOT CONTACTED. THE APPROXIMATE FAILURE MILEAGE WAS 13,000.

Mileage: 13,000

TL* THE CONTACT OWNS A 2017 HYUNDAI SONATA PLUG-IN HYBRID. WHILE DRIVING APPROXIMATELY 20 MPH AND ABOVE, THE CRUISE CONTROL CAUSED THE VEHICLE TO ALMOST CRASH INTO THE PRECEDING VEHICLE. THERE WERE NO WARNING INDICATORS ILLUMINATED. THE DEALER WAS NOT CONTACTED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE WAS NOT DIAGNOSED. THE CONTACT WAS TOO SCARED TO DRIVE THE VEHICLE. THE FAILURE MILEAGE WAS 6.

Mileage: 6

ON 3/15/2017 AROUND 8AM, I STARTED MY CAR TO LEAVE FOR WORK AND THE CAR SHOWED A WARNING "CHECK HYBRID SYSTEM" AND THE CORRESPONDING WARNING LIGHT CAME ON. THE GASOLINE ENGINE ALSO STARTED RIGHT AWAY AND STAYED ON, EVEN THOUGH THE EV BATTERY WAS FULL. THE ENGINE REMAINED ON THROUGHOUT MY COMMUTE TO WORK AND BACK TO HOME IN THE EVENING. I PLUGGED THE CAR IN MY GARAGE FOR CHARGING OVERNIGHT WITH THE TIMER SET TO START THE CHARGING AT 10PM. AROUND 10:45PM, MY WIFE AND I OPENED THE INTERNAL GARAGE DOOR FROM INSIDE THE HOUSE AND IMMEDIATELY SMELLED EXHAUST FUMES AND HEARD THE ENGINE RUNNING. I OPENED THE GARAGE OVERHEAD DOOR RIGHT AWAY AND UNPLUGGED THE CHARGING CABLE WHICH TURNED THE ENGINE OFF. JUST TO BE SURE, I PLUGGED THE CABLE IN AGAIN AND TURNED OFF THE TIMER TO RESTART THE CHARGING IMMEDIATELY. AS SOON AS THE CHARGING STARTED, THE ENGINE CAME ON AND AFTER A FEW SECONDS STARTED REVVING UP ALSO. I IMMEDIATELY UNPLUGGED THE CHARGING CABLE AND ENGINE STOPPED. I TOOK THE CAR TO THE DEALER TODAY AND AM WAITING TO HEAR BACK FROM THE DEALER. I THINK THIS IS A POTENTIALLY SERIOUS SAFETY ISSUE AND HENCE I AM REPORTING IT.

Mileage: 2,900