The MOT Files

Known faults, from the test record

Hyundai Ioniq common problems

What fails on the Hyundai Ioniq at MOT, which parts are behind it, and how each model year compares. From 48,982 DVSA test records.

Data updated

Quick answer

The Hyundai Ioniq's most common MOT problems are tyres, bulbs and lamps, wiper blades and washers, recorded in 54.6%, 20.4% and 18.1% of failed tests respectively. By model year, 2021 cars pass most often (88.5%) and 2017 cars least (83.8%), though most of that gap is age. Every figure here is what testers recorded, not what owners reported.

A “common problems” list is usually a forum thread: whoever had the worst day writes the longest post. This one is built the other way, from every Hyundai Ioniq that took an MOT last year and what the tester wrote down. It cannot see breakdowns, electrical gremlins or a gearbox that hunts, because the test does not check those. What it can see, it sees across 48,982 cars.

By component

What wears out on a Ioniq

Failure items grouped by the part behind them, with the share of failed Hyundai Ioniq tests recording each. A part can carry several DVSA wordings; they are listed beneath. One failed test often lists several items, so shares do not sum to 100%.

  1. 1.Tyres

    54.6% of failed tests

    Tread wears with every mile and sidewalls age and take kerb damage; the legal minimum is 1.6 mm across the central three-quarters.

    • “Tyre tread depth not in accordance with the requirements” — explained22.7%
    • “A tyre seriously damaged” — explained14.2%
    • “A tyre cords visible or damaged” — explained9.0%
    • “A tyre seriously damaged” — explained3.2%

    Across all cars, tyres failures run at a similar rate at every age, because they are replaced on a cycle rather than wearing out with the car. How long tyres last

  2. 2.Bulbs and lamps

    20.4% of failed tests

    Filament bulbs simply expire; the cheapest and most avoidable failure on the test, and one of the most recorded.

    • “Headlamp levelling device inoperative” — explained6.4%
    • “A rear registration plate lamp or light source missing or inoperative in the case of a single lamp or all lamps” — explained5.2%
    • “A headlamp or light source missing, inoperative or more than ½ not functioning in the case of LED” — explained2.6%
    • “A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning” — explained2.6%

    Across all cars, bulbs and lamps failures climb 15-fold between three and fifteen years, peaking at 15+ years. How long bulbs and lamps last

  3. 3.Wiper blades and washers

    18.1% of failed tests

    Rubber blades harden and split within a year or two; washer jets block and pumps fail.

    • “Wiper blade missing or obviously not clearing the windscreen” — explained12.8%
    • “Windscreen washers not working or not providing sufficient fluid to clear the windscreen” — explained2.8%
    • “Windscreen washers not working or not providing sufficient fluid to clear the windscreen” — explained2.4%

    Across all cars, wiper blades and washers failures run at a similar rate at every age, because they are replaced on a cycle rather than wearing out with the car. How long wiper blades and washers last

  4. 4.Parking brake

    12.9% of failed tests

    Cables stretch and seize, rear shoes and adjusters wear; efficiency is measured on the roller tester against the vehicle's weight.

    • “Parking brake efficiency below minimum requirement” — explained8.2%
    • “Parking brake efficiency less than 50% of the required value” — explained2.1%
    • “Parking brake inoperative on one side” — explained1.6%
    • “Parking brake lever has excessive movement indicating incorrect adjustment” — explained1.0%

  5. 5.Headlamp aim

    7.8% of failed tests

    Aim drifts with sagging suspension, a knocked lamp or a botched bulb change; adjustment, not a part.

    • “The aim of a headlamp is not within limits laid down in the requirements” — explained3.3%
    • “The aim of a headlamp is not within limits laid down in the requirements” — explained1.9%
    • “The aim of a headlamp is not within limits laid down in the requirements” — explained1.6%
    • “Headlamp aim unable to be tested” — explained1.0%

  6. 6.Suspension bushes

    7.6% of failed tests

    Rubber bushes in arms and links perish and split with age and load; the most recorded suspension item on the test.

    • “A suspension joint dust cover missing or no longer prevents the ingress of dirt etc” — explained4.8%
    • “A suspension joint dust cover missing or no longer prevents the ingress of dirt etc” — explained1.9%
    • “A suspension pin, bush or joint excessively worn” — explained0.9%

    Across all cars, suspension bushes failures climb 20-fold between three and fifteen years, peaking at 15+ years. How long suspension bushes last

  7. 7.Brake discs

    6.7% of failed tests

    Discs thin with each pad set and pit or corrode when lightly used; failure is for significant wear, fracture or insecurity, advisory for surface condition.

    • “Brake disc or drum significantly and obviously worn” — explained3.0%
    • “Brake disc or drum excessively weakened, insecure or fractured” — explained1.9%
    • “Excessive fluctuation in brake effort through each wheel revolution.” — explained1.8%

    Across all cars, brake discs failures climb 3-fold between three and fifteen years, peaking at 12–14 years. How long brake discs last

  8. 8.Brake servo and performance

    6.3% of failed tests

    A servo or master cylinder fault shows as a hard pedal or poor overall efficiency on the tester; rare, and a fault rather than wear.

    • “Service brake efficiency below minimum requirement” — explained6.3%

By registration year

Ioniq problems by year

MOT pass rate for Hyundai Ioniq cars by the year they were first registered, from years with at least 1,000 tests. Every car in a row is the same age, so the rate is raw. Neighbouring years differ by a year of wear — a step of a point or two is age. No single step here is large enough to point at a generation change.

201784%
201885%+0.8
201986%+1.2
202088%+2.0
202189%+0.7
202285%−3.5

Last column: change on the previous year, in points. Years registered within the last three years have not yet been tested and are not shown.

Before it fails

What testers warn Ioniq owners about

Advisories are the same parts a year or two earlier. Share of all Hyundai Ioniq tests carrying an advisory for each.

Go deeper

The rest of the Ioniq file

Common questions

What are the most common problems with a Hyundai Ioniq?
Going by what fails the MOT, tyres (recorded in 54.6% of failed tests), bulbs and lamps (recorded in 20.4% of failed tests), and wiper blades and washers (recorded in 18.1% of failed tests). These are the items testers actually record across 48,982 tests, not reports from owners, so they describe what goes wrong at the point where it has to be fixed.
Which Hyundai Ioniq year is the most reliable?
By MOT pass rate, Hyundai Ioniq cars registered in 2021 do best at 88.5% and 2017 cars do worst at 83.8%. Most of that ordering is simply age — newer cars pass more — so read the year table for steps larger than a couple of points between neighbouring years; those mark a change in the cars rather than the calendar.
Is the Hyundai Ioniq reliable?
The Hyundai Ioniq passes 86.2% of MOTs unadjusted; its fleet is too narrow in age or mileage for a fair national comparison. An MOT measures roadworthiness on the day rather than breakdowns or running costs, so this is a reliability measure in the narrow sense: how often the car meets the legal standard, and what stops it.
What should I check when buying a used Hyundai Ioniq?
Start with what fails most: tyres, bulbs and lamps, wiper blades and washers. Then read the car's own MOT history for advisories carried year to year without repair — the model tells you what to expect, the history tells you whether this owner dealt with it.

Analysis built from DVSA data of