Most common 2018 Hyundai Ioniq Hybrid problems
Share of the 13 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Hyundai Ioniq Hybrid complaints by model year
Best Ioniq Hybrid years: 2019. Years to avoid: 2022, 2020. Compare all years →
2018 Hyundai Ioniq Hybrid recalls (2)
Hybrid propulsion system › Inverter
Hyundai Motor America (Hyundai) is recalling certain 2017-2018 Ioniq HEV and Ionic PHV vehicles previously recalled under recall number 18V-704. The Power Relay Assembly (PRA) located underneath the rear seat may overheat.
Remedy: Dealers will inspect and replace the main relay or PRA, as necessary, free of charge. Owner notification letters were mailed August 23, 2022. Owners may contact Hyundai customer service at 1-855-371-9460.
Hybrid propulsion system › Inverter
Hyundai Motor America (Hyundai) is recalling certain 2017-2018 Hyundai Ioniq Hybrid and 2018 Ioniq Plug-In Hybrid vehicles. The Main Relay within the Power Relay Assembly (PRA) may have inadequate connections between its contacts, causing increased electrical resistance.
Remedy: Hyundai will notify owners, and dealers will inspect the Power Relay Assembly (PRA) for damage. If no damage is found, the main relay will be replaced. If damage is found, the PRA will be replaced.
NHTSA defect investigations
Federal safety investigators have looked into a possible defect involving the 2018 Hyundai Ioniq Hybrid:
Pedestrian alert sounds
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles.
What 2018 Hyundai Ioniq Hybrid owners say
Electrical system
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. …
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.
Engine & cooling
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.
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 .
Transmission & drivetrain
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. …
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
Frequently asked questions
Is the 2018 Hyundai Ioniq Hybrid a good car?
There isn't enough complaint history for the Ioniq Hybrid to compare model years reliably. So far owners have filed 13 complaints with NHTSA.
What is the most common problem with the 2018 Hyundai Ioniq Hybrid?
The electrical system — 3 complaints, 23% of all complaints for this model year. Next are the engine & cooling (3) and transmission & drivetrain (3).
How many recalls does the 2018 Hyundai Ioniq Hybrid have?
There are 2 recalls for the 2018 Hyundai Ioniq Hybrid, the most recent from June 28, 2022 (inverter). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Hyundai Ioniq Hybrid?
The best years by complaints, compared at the same age, are 2019. Years to avoid or approach with caution: 2022 and 2020. See the full Hyundai Ioniq Hybrid years comparison.
At what mileage do 2018 Hyundai Ioniq Hybrid problems happen?
The median mileage reported in complaints is about 3,000 miles; 88% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.