AutoUtility currently tracks 13 official NHTSA owner defect complaints for the 2018 Hyundai Ioniq. Engine & Cooling issues are the most frequently reported category, appearing in 3 complaints (23.1% of submitted records). Among these NHTSA complaint records, 2 filings cite a crash, 1 reports one or more injuries.
- • Total NHTSA Complaints: 13 reports
- • #1 Reported Problem Area: Engine & Cooling (3 reports • 23.1% of submitted complaints)
- • Secondary Problem Areas: Powertrain & Transmission (3), Electrical System (3)
- • Crash-Citing Complaints: 2 filings
- • Fire-Citing Complaints: 0 filings
- • Complaints Reporting Injuries / Fatalities: 1 injury filings • 0 fatality filings
Most Reported Problems for 2018 Hyundai Ioniq
Top automotive subsystem defect categories ranked by unique owner complaint volume in federal records
Engine & Cooling
Powertrain & Transmission
Electrical System
NHTSA records list 1 official safety recall campaign for this model year involving the same broad component area:
- Campaign #21V944000 ELECTRICAL SYSTEM:PROPULSION SYSTEM:CHARGING:MODULE:ONBOARD (OBCM)
Driver Assistance & Safety Tech
Air Bags & Restraints
Recent NHTSA Owner Reports for 2018 Hyundai Ioniq
Representative defect filings submitted by owners to the NHTSA Office of Defects Investigation
"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..."
"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..."
"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..."
"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..."
"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..."
Complaint History for Hyundai Ioniq
Reported defect complaint volume across sibling model years (2017–2026)
| Model Year | NHTSA Complaints | Crash Reports | Safety Recalls | Detailed Report |
|---|---|---|---|---|
| 2017 Hyundai Ioniq | 49 | 5 | 5 | View 2017 Problems → |
| 2018 Hyundai Ioniq Current Page | 13 | 2 | 3 | Current |
| 2019 Hyundai Ioniq | 22 | 6 | 2 | View 2019 Problems → |
| 2020 Hyundai Ioniq | 29 | 6 | 1 | View 2020 Problems → |
| 2021 Hyundai Ioniq | 0 | 0 | 0 | View 2021 Problems → |
| 2022 Hyundai Ioniq | 21 | 2 | 0 | View 2022 Problems → |
| 2023 Hyundai Ioniq | 0 | 0 | 0 | View 2023 Problems → |
| 2024 Hyundai Ioniq | 0 | 0 | 0 | View 2024 Problems → |
| 2025 Hyundai Ioniq | 0 | 0 | 0 | View 2025 Problems → |
| 2026 Hyundai Ioniq | 0 | 0 | 0 | View 2026 Problems → |
Detailed NHTSA Component Breakdown for 2018 Hyundai Ioniq
Complete distribution of consumer defect reports across all 9 granular NHTSA system and subsystem classifications
| Vehicle Component / System | Total Complaints | Crash Reports | Fire Reports | Reported Injury Entries | Reported Fatality Entries |
|---|---|---|---|---|---|
| Powertrain NHTSA category: POWER TRAIN | 3 | 1 | 0 | 0 | 0 |
| Engine NHTSA category: ENGINE | 2 | 0 | 0 | 0 | 0 |
| Vehicle Speed Control NHTSA category: VEHICLE SPEED CONTROL | 2 | 0 | 0 | 0 | 0 |
| Air Bags NHTSA category: AIR BAGS | 1 | 1 | 0 | 2 | 0 |
| ELECTRICAL SYSTEM,ENGINE | 1 | 0 | 0 | 0 | 0 |
| ELECTRICAL SYSTEM,UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| STEERING,ELECTRICAL SYSTEM,VISIBILITY/WIPER | 1 | 0 | 0 | 0 | 0 |
| Other / Uncategorized NHTSA category: UNKNOWN OR OTHER | 1 | 0 | 0 | 0 | 0 |
| UNKNOWN OR OTHER,SERVICE BRAKES | 1 | 0 | 0 | 0 | 0 |
Official NHTSA Defect Investigations (1)
Formal safety defect inquiries and engineering analyses opened by the NHTSA Office of Defects Investigation (ODI)
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. The standard applies to hybrid and electric vehicles that have a gross vehicle weight ra...
The complaint records on this page are retrieved directly from the NHTSA Office of Defects Investigation (ODI) public database.
Local Production Store Compiled: August 2026 • Deterministic Audited Dataset • Zero Dynamic External API Runtime Latency.