2017 Hyundai Sonata PLUG-IN Hybrid

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.

The engine started knocking on the freeway and all the lights in the car went off. The engine failed and I barely made it off the freeway. I was almost hit by two cars trying to get to a safe place. The engine has the same issue as the other morsels that have recalled the engine for the same rod failure issue but Hyundai has not extended the recall to the plug in hybrid. This model also bends to be recalled because it is a danger to all owners and other drivers. Hyundai declined to repair the defective engine.

On cold mornings, during the first start of the day, and while going downhill, the internal combustion engine comes on while running on electrical power from the battery. This is understandably to heat up the engine to ideal temperatures. But within a minute, the car gives a hybrid battery error, fully loses power requiring to be stopped immediately. This is obviously dangerous anywhere but particularly downhill. The car requires to be restarted after pulling over 1-3 times until the engine / battery reach ideal temperatures. Then the car runs as expected. The dealership has been unable to diagnose the issue and chalked it up to an unrelated recall - which has been fixed, but the issue still occurs risking the safety of the people inside the car and around.

While driving on surface streets (10-15 MPH) about 5 minutes out from our house, the accelerator stopped working properly and a warning popped up along the lines of "Hybrid HEV warning: Please shut off engine and restart." Since there were no other cars behind us, we were able to thankfully pull over without too much trouble. However, if we had been on a highway this would have been incredibly dangerous, as we would have lost speed quickly and had no safe way to pull over. There were no warnings prior to this happening on that day. The car just sudden stopped working and then lights popped on. Using an OBD reader, the issue code was P0DE7: Hybrid/EV Battery - Cell Voltage High. We are going to the dealer at the earliest appointment to have it looked at, and the car is clearly not safe for anything but surface roads with easy pull-offs. Related Items: A week or so ago, we had an incident where the car was a bit sluggish to accelerate after a right hand turn (e.g., needed to take foot off the gas, then put it back on after a moment to accelerate). However, no check engine light came on and the car ran fine after. A second potential related item was that the expected mileage on battery-only had reduced from about 27 to 23 miles on a full charge. This occurred within the last two months before this issue.

The contact owns a 2017 HYUNDAI Sonata Plug-In Hybrid. The contact stated while driving approximately 35 MPH, the vehicle started making a loud knocking sound. The contact pulled over and noticed an excessive amount of oil underneath the front of the vehicle. The contact took the vehicle to a certified mechanic who diagnosed that there was a hole in the engine block. The mechanic showed the contact a piece of metal that had fractured from the engine. The contact stated that three days later while driving approximately 25 MPH, the vehicle stalled. The vehicle was towed to the dealer who confirmed that the vehicle was not included in NHTSA Campaign Number: 21V727000 (Engine). The vehicle had not been repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 76,000.

On August 31st 2021, While driving my 2017 Hyundai Sonata PHEV on interstate 95 the check engine and hybrid system warning lights came on and the car simultaneously lost power for 3-4 seconds, which caused a decrease in speed from 65 to approximately 50 mph. There was a tractor trailer behind me but thankfully it braked to avoid striking my car. The car regained partial power and I was able to drive it home. I took the car to the dealership to have it repaired. The dealer diagnosed a faulty battery management system, and replaced this component after 17 days. On September 25, while driving on a street the car once again lost power for 3-4 seconds, with the check engine and hybrid system lights simultaneously illuminated. There was a recall on my vehicle several years ago to prevent this dangerous problem. I had the car repaired at that time but clearly the problem was not fixed as my car has subsequently lost power on two separate occasions, in a manner that could have easily caused a crash.

The trunk will not open by any means, at times it can be opened, but the emergency release does not work. If anyone gets in, they cannot get out, especially with the Hybrids which do not have fold down back seats. Federal mandate states the trunk must have an operational emergency release, but with the trunk latch issue, the emergency release does NOT work.