2018 Hyundai Ioniq Hybrid Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 2018 Hyundai Ioniq Hybrid, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Engine320.0%
- Powertrain (other)320.0%
- Electrical320.0%
- Driver assistance213.3%
- Visibility16.7%
- Brakes16.7%
- Steering16.7%
- Airbags16.7%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
My 2018 Hyundai Ioniq Hybrid has a safety-critical transmission defect. The vehicle slips violently from 1st to 2nd gear, loses acceleration, and causes unpredictable hesitation. This creates a danger when merging onto highways or crossing intersections. Hyundai refused goodwill assistance, denied escalation, and directed me to BBB Auto Line, but BBB does not accept 2018 vehicles. This defect matches known DCT failures in Hyundai hybrid models and presents a significant safety risk, especially when transporting my two young children ( we lost mother during the childbirth .
The car engine started to stall, the engine light came on and advised me to shut off engine then I pulled over and smoke immidiatley filled the cabin and outside the hood. My engine could have blown up. Had I not pulled over so quickly my car would have caught fire and I would have died. Yes the Hyundai Folsom inspected the car and listed issue was a hole in the engine block. They stated it was caused by premature wearing of the rod bearings and refused to repair. The ONLY warning happened within seconds of the car stalling and failing to accelerate before I pulled over. The first symptoms was a noise I couldne place 5 days prior. It was a mild knocking sound that was subtle.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Powertrain (other)
Powertrain reports that are not specifically the engine or transmission — driveshafts, axles, transfer cases and differentials.
From owner reports, verbatim
The clutch failed and the clutch and I believe the clutch actuator had to be replaced. It was not available for inspection upon request. My safety and the risk of others were compromised by the constant jerking and sputtering, of the gears that took place during vehicle operation. My acceleration was laggy and at some points nearly unresponsive. The vehicle was inspected by service technicians. A warning light saying: Warning please check Hybrid Driving System, Do not drive vehicle was illuminated. Mid to late October 2023
There is a defect with the transmission control module (TCM) and dual-clutch transmission (DCT). This defect prevents the car from properly accelerating from a stop. The defect manifests in the following ways when pressing the accelerator: unresponsive or sluggish acceleration, jerking, shuddering, failure to shift, stalling and complete loss of power. Typically, the TCM defect manifests in two ways: shuddering/delayed brake release, which has happened over 20 times and loss of power/engine revving out of gear which has occured three times. These issues are unpredictable, unrepeatable and dangerous. I usually experience them while waiting at stop lights in busy intersections. Delayed and unpredictable acceleration and shifting could cause a traffic accident. I've notified the dealership three times and had it serviced once by licensed Hyundai technicians at the same dealership. They couldn't replicate the issue and claimed they had never heard of the problem. There are no warning lights when this issue occurs and the dealship said there were no diagnostic codes indicating the problem. Defective TCM & DCT software is a known issue that resulted in a recall campaign for the 2016 Hyundai Tucson. This issue has been documented in the following vehicles: 2017 Hyundai Elantra Eco, 2017 Hyundai Sonata Eco, 2016 – 2017 Hyundai Tucson, 2016 Hyunda Veloster Turbo. Hyundai issued the following service bulletins informing dealerships about the TCU software issue specific to the Tucson: #5NP-X7J3D-10, TSB# 16-01-035, #5NP- S9D9P-10
Too few reports in this category for a page of its own — they appear in the full complaint list.
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
My lcd screen constantly goes black. A couple times the steering wheel locked the wipers and washer fluid went off at the same time. I had to hit the brakes and power the car on and off to reset it while making a turn. When having my window motor replaced for the SECOND time my dash where the speed is at all when black while driving on the freeway. I had to pull over and restart the car. My paint and my clear coat is separating on my trunk. It looks white not oxidation just separating and white. My driver side door button to lock the car kept getting stuck and was locking and unlocking. this left the possibilities of my car getting stolen from the door lock and the window motor leaving my window half down. My safety and the safety of others is obviously at risk with the electrical malfunctions. My local dealership left my issue’s unresolved for currently FIVE months with little to no compensation. I guess the life of my family and everyone else on the road is only $420.
IT BEGAN SHORTLY AFTER I PURCHASED THE CAR IN FEB 2018 WITH THE A/C WORKING ONLY INTERMITTENTLY AND THE SETTINGS ON THE CLUSTER HAVING THE SAME PROBLEM, AND THIS ELECTRICAL PROBLEM ESCALATED INTO A SAFETY ISSUE WHEN ON DEC 6 THE RKE FAILED (BATTERY ON FOB STRONG) AND A RE-START ON CAR DID NOT WORK, UNTIL THE SPARE KEY WAS TRIED. SINCE DEALER FOUND NO PROBLEM WITH EITHER KEY, THE SAFETY ISSUE REMAINS A MAJOR CONCERN FOR THE SENIOR CITIZEN OWNER WHO MIGHT GET CAUGHT AGAIN WITHOUT ACCESS TO THE CAR AND WITH A NON-FUNCTIONING ENGINE. THE ELECTRICAL PROBLEM SHOWS ITSELF INTERMITTENTLY IN UNPROVOKED BEEPS OF THE PASSENGER DOOR, AS WELL AS IN THE CLUSTER SETTINGS. *JS
Too few reports in this category for a page of its own — they appear in the full complaint list.
Driver assistance
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.
From owner reports, verbatim
WHILE DRIVING THIS MORNING (SMART CRUISE CONTROL DISABLED BY THE WEATHER), I SET THE CRUISE CONTROL AND EVERYTHING WAS WORKING OK. I CANCELLED DUE TO TRAFFIC AND REENGAGED WITHOUT ISSUE. WHEN I REQUESTED ADDITIONAL SPEED WITH THE INCREASE CONTROL, THE CAR ACCELERATED AND CONTINUED TO ACCELERATE AND DID NOT STOP ACCELERATING UNTIL I HIT THE BRAKES AND CANCELLED THE CRUISE CONTROL. THIS IS VERY UNSAFE. I EXPECT THIS FIXED AND WILL CONTACT THE NHTSA AND ALSO FILE A COMPLAINT WITH THEM. THIS IS DANGEROUS AND IT IS ONLY DUE TO MY ABILITY TO QUICKLY REACT DID I AVERT AN ACCIDENT IN SNOWY CONDITIONS! ***** I AM CHECKING THE NO CRASH BUTTON ONLY BECAUSE MY QUICK ACTION AND RESPONSE AVERTED AN ACCIDENT, BUT THIS IS VERY DANGEROUS! *****
I AM VERY CONCERNED ABOUT THE CRUISE CONTROL. WHILE DRIVING THIS MORNING (SMART CRUISE CONTROL DISABLED BY THE WEATHER), I SET THE CRUISE CONTROL AND EVERYTHING WAS WORKING OK. I CANCELLED DUE TO TRAFFIC AND REENGAGED WITHOUT ISSUE. WHEN I REQUESTED ADDITIONAL SPEED WITH THE INCREASE CONTROL, THE CAR ACCELERATED AND CONTINUED TO ACCELERATE AND DID NOT STOP ACCELERATING UNTIL I HIT THE BRAKES AND CANCELLED THE CRUISE CONTROL. THIS IS VERY UNSAFE. I EXPECT THIS FIXED AND WILL CONTACT THE NHTSA AND ALSO FILE A COMPLAINT WITH THEM. THIS IS DANGEROUS AND IT IS ONLY DUE TO MY ABILITY TO QUICKLY REACT DID I AVERT AN ACCIDENT IN SNOWY CONDITIONS! -SCOTT
Too few reports in this category for a page of its own — they appear in the full complaint list.
Visibility
Reports naming windshields, glass, wipers, defrosters and mirrors.
From owner reports, verbatim
My lcd screen constantly goes black. A couple times the steering wheel locked the wipers and washer fluid went off at the same time. I had to hit the brakes and power the car on and off to reset it while making a turn. When having my window motor replaced for the SECOND time my dash where the speed is at all when black while driving on the freeway. I had to pull over and restart the car. My paint and my clear coat is separating on my trunk. It looks white not oxidation just separating and white. My driver side door button to lock the car kept getting stuck and was locking and unlocking. this left the possibilities of my car getting stolen from the door lock and the window motor leaving my window half down. My safety and the safety of others is obviously at risk with the electrical malfunctions. My local dealership left my issue’s unresolved for currently FIVE months with little to no compensation. I guess the life of my family and everyone else on the road is only $420.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
CLICKING NOISE COMING FROM THE BOTTOM OF THE ENGINE EVERY TIME THE BRAKE PEDAL IS DEPRESSED. SOMETIMES THE CLICKING NOISE WILL CONTINUE AFTER THE CAR HAS BEEN PARKED AND LOCKED. THE FIRST TIME THE CLICKING STARTED, I PARKED MY CAR AND A WARNING "CHECK BRAKE SYSTEM" APPEARED BRIEFLY IN MY DASHBOARD DISPLAY BUT THE CLICKING PERSISTED. THE PEDAL FELT SLUGGISH WITH NOT MUCH RESISTANCE.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Steering
Reports naming the steering system — racks, columns, power-steering assist and steering linkage.
From owner reports, verbatim
My lcd screen constantly goes black. A couple times the steering wheel locked the wipers and washer fluid went off at the same time. I had to hit the brakes and power the car on and off to reset it while making a turn. When having my window motor replaced for the SECOND time my dash where the speed is at all when black while driving on the freeway. I had to pull over and restart the car. My paint and my clear coat is separating on my trunk. It looks white not oxidation just separating and white. My driver side door button to lock the car kept getting stuck and was locking and unlocking. this left the possibilities of my car getting stolen from the door lock and the window motor leaving my window half down. My safety and the safety of others is obviously at risk with the electrical malfunctions. My local dealership left my issue’s unresolved for currently FIVE months with little to no compensation. I guess the life of my family and everyone else on the road is only $420.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Airbags
Reports naming the air-bag system — deployment behaviour, inflators, sensors and warning lights.
From owner reports, verbatim
The contact owned a 2018 Hyundai Ioniq Hybrid. The contact stated while driving 75 MPH with her aunt in the front passenger's side seat, another vehicle suddenly merged into the contact's lane, causing the passenger's side of the vehicle to crash into the driver's side of the other vehicle. The vehicle then veered into a ditch on the right side of the road. The air bags failed to deploy. There was no warning light illuminated. The contact and her aunt exited the vehicle through the rear doors because the front doors were blocked by the bushes. The contact sustained pain in the right knee and ankle. The contact's aunt sustained pain in the right knee. The ambulance transported both passengers to the hospital, where they were informed that no other injuries were found. A police report was filed, but the contact did not have the police report information available. The vehicle was towed and totaled by the insurance company. The dealer was notified of the failure. The manufacturer was notified of the failure and a case was opened; however, the case was later closed. The failure mileage was approximately 85,000.
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .