The sensible hybrid that undercuts the Prius
The Hyundai Ioniq (2016-2022) was a direct competitor to the Toyota Prius, offered in hybrid, plug-in hybrid and fully electric versions on the same platform. It targeted eco-conscious buyers who wanted conventional car styling rather than the Prius's polarising design. It undercut the Prius on price while offering a generous equipment list and Hyundai's five-year warranty.
We track 5 known issues across the Hyundai Ioniq range, with 3 classified as significant. Knowing which variants and configurations to approach with caution can save you from expensive surprises after purchase.
Found a Hyundai Ioniq? Enter the reg to see which of our 5 known issues apply to that exact car, plus full MOT history and mileage checks.
AE (2016–2024) — Engine options included the 1.6 GDI Hybrid, 1.6 GDI Hybrid, Electric. We track 5 known issues on this generation, with 3 classified as significant. The most significant concern is Parking brake system failures (£250–£600 to address).
The electronic parking brake (EPB) system shows multiple failure modes across hybrid and electric variants, with MOT data indicating failures at 3.2-61.6x the fleet average rate. The system uses electric actuators on the rear calipers controlled by a central EPB module. Failures include actuator motor burnout, cable stretch, control module software errors, and calibration drift. Electric variants show the highest failure rates, potentially due to increased system complexity with regenerative braking integration.
EPB system failure can prevent the parking brake from engaging or disengaging, potentially leaving the car immobilised or unsafe to park on inclines. Repair typically involves EPB actuator replacement (£300-600 per side) or control module replacement (£400-800). The car remains safe to drive but should not be parked on inclines without wheel chocks.
Check brake disc condition for lipping or scoring. Test braking at moderate speed for pulling to one side or vibration through the steering wheel. Review MOT advisories for brake-related items.
Hybrid variants show service brake efficiency failures at 5.3x the fleet average rate, with a worsening trend from 2020-2024. The regenerative braking system reduces mechanical brake usage, leading to premature brake disc corrosion and pad glazing. The brake-by-wire system can mask declining brake performance until MOT testing reveals efficiency below legal requirements. This affects the mechanical brake system's ability to provide adequate stopping force when regenerative braking is unavailable.
Reduced brake efficiency can result in MOT failure and potentially dangerous stopping distances. The hybrid system may compensate initially, masking the degradation until complete system assessment. Repair typically involves disc and pad replacement plus system bleeding. The brake-by-wire integration means specialist diagnosis is often required.
Check brake disc condition for lipping or scoring. Test braking at moderate speed for pulling to one side or vibration through the steering wheel. Review MOT advisories for brake-related items.
The 6-speed dual-clutch transmission (DCT) fitted to hybrid variants can develop juddering during engagement, particularly from standstill or at low speeds. This typically manifests as clutch pack wear, transmission fluid degradation, or mechatronic unit faults. The issue is exacerbated by the hybrid system's frequent engine start-stop cycles and the integration complexity between the electric motor and transmission. Early symptoms include harsh engagement and delayed response to throttle inputs.
Progressive DCT wear leads to increasingly severe juddering and eventual clutch pack failure. Complete transmission replacement or major overhaul typically costs £3000-5000. The vehicle remains driveable but becomes uncomfortable and may suffer reduced fuel economy as the hybrid system cannot operate efficiently with transmission faults.
Test the automatic gearbox extensively in slow traffic, car parks and on hill starts. Feel for any juddering, hesitation or clunking during gear changes. Try repeated low-speed manoeuvres as this is where problems are most apparent.
Hybrid variants show MIL (malfunction indicator light) activation at This typically relates to hybrid system integration issues, emissions system faults, or software conflicts between the petrol engine ECU and hybrid control modules. Common causes include oxygen sensor drift, EGR valve carbon buildup from infrequent petrol engine operation, and hybrid battery management system communication errors.
MIL activation indicates a fault in the engine management or emissions system that requires diagnosis. While often minor issues like sensor drift, the fault can affect hybrid system efficiency and may prevent the car passing its MOT. Diagnostic costs are typically £60-120, with repair costs varying from £50-500 depending on the root cause.
Check all electrical functions systematically: windows, mirrors, lights, infotainment, heated seats, air conditioning. Look for any warning lights on the dashboard. A diagnostic scan before purchase can reveal stored fault codes.
The Ioniq demonstrates above-average reliability for both hybrid and electric powertrains across the first generation. The Kappa petrol engine benefits from Atkinson cycle operation and reduced loading due to electric motor assistance. Electric variants show minimal powertrain issues beyond normal battery degradation patterns. Both systems benefit from Hyundai's 5-year warranty coverage and established UK dealer network support for hybrid/electric technology.
This entry acknowledges the model's positive reliability record. Standard maintenance intervals should be followed, with particular attention to hybrid system servicing requirements. The main considerations are battery replacement costs after warranty expiry (typically £3000-5000 for hybrid, £8000-12000 for electric) and ensuring specialist maintenance capability.
Listen for any unusual knocking, tapping or rattling from the engine at idle and under load. Check the oil for metal particles or discolouration. On higher-mileage examples, a professional compression test can reveal internal wear before it becomes critical.
For the full breakdown of all 5 tracked issues with repair costs, see the Hyundai Ioniq common problems page.
Based on 133k real DVSA MOT tests, the Hyundai Ioniq fails more often than average on several items. The biggest outlier is parking brake inefficient at 62x the fleet average, followed by headlight fault (26x).
When viewing a specific car, check its MOT history for recurring advisories in these categories. See the full Hyundai Ioniq MOT failure breakdown for data at every mileage point.
Routine servicing (oil and filter change every 10k miles) typically costs £80–£120 at an independent garage.
See the full Hyundai Ioniq service schedule for every interval and cost breakdown.
The Hyundai Ioniq is a solid choice on the used market, though not without its quirks. The issues we track are well-understood and largely avoidable if you know what to look for. A thorough inspection and complete service history go a long way. 2020-2022 facelift models are the ones to buy, with improved reliability records and fewer reported faults. The 2017 model year is the most problematic with clutch switch defects and electrical issues. The 2020 hybrid is singled out as a particularly strong year.
Before committing, check the car's full MOT history, verify the service record is complete, and if possible arrange a specialist inspection. Enter any registration into our free report to see the complete picture.
Get Car Wise maintains a database of known mechanical issues for every popular car on UK roads, tracking the faults that owners, specialists and DVSA data reveal.
When you run a report on a specific Hyundai Ioniq, we cross-reference the exact variant, engine and age against our database of 5 known issues. Combined with full MOT history analysis, mileage verification and DVLA data, you get a complete picture before viewing.
Enter the registration for MOT history, mileage verification, known faults for that exact variant, and a Get Car Wise Score.
This guide was compiled from independent expert reviews, DVSA MOT data, specialist workshops and our own database of 5 known Hyundai Ioniq issues. We are not affiliated with any source listed.