Fault File
All models / All cars / Small SUVs / Mazda CX-30

Mazda CX-30

All generations and engines together · 16,138 MOT tests in the 2025 data

How this model wears

Mazda CX-30Class average, all tracked models

Known issues

Measured

Computed from DVSA MOT results, all of Great Britain, 2025. Nothing here is opinion.

What testers flag

Share of tests where each item was recorded. The dark tick is the class average across all tracked models; bars are scaled within each group.

Faults with the car itself

The rows that judge the model rather than its keeper. 16,111 tests in this band.

A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Advisory
12.0%class 2.1%
A shock absorber damaged to the extent that it does not function or showing signs of severe leakage
Fail
0.6%class 0.2%
Engine MIL illuminated indicating a malfunction
Fail
0.6%class 0.3%
Brake fluid significantly below minimum mark
Advisory
0.3%class 0.0%
A suspension pin, bush or joint excessively worn
Advisory
0.3%class 2.4%
A battery insecure but not likely to fall from carrier
Minor
0.2%class 0.0%

Wear, upkeep and luck

Tyres, pads and stone chips say more about how the car was driven and maintained than about how it was built.

Tyre tread depth not in accordance with the requirements
Advisory
22.4%class 18.8%
Brake disc or drum excessively weakened, insecure or fractured
Advisory
18.1%class 7.0%
A brake lining or pad worn below 1.5mm
Advisory
13.0%class 7.2%
A tyre seriously damaged
Advisory
10.3%class 13.1%
Brake disc or drum significantly and obviously worn
Advisory
4.3%class 1.9%
Child Seat fitted not allowing full inspection of adult belt
Advisory
2.9%class 2.1%
Wiper blade missing or obviously not clearing the windscreen
Fail
2.4%class 1.7%
Wiper blade defective
Minor
2.0%class 1.1%

Unconfirmed issues

Reported

Owner folklore from forums and the motoring press. Most of it never shows up in an MOT, which is why this section exists at all.

Smart Brake Support false braking (recall)

Confirmed pattern

On cars built between November 2018 and October 2019, the automated Smart Brake Support system could activate on its own and bring the car to an unexpected stop with no obstacle present. Mazda recalled the affected cars and reprogrammed the SBS software free of charge at a dealer. Because these are early cars that have often changed hands more than once, it's worth checking the registration on the DVSA recall checker before you buy, since a forgotten recall is a common way this slips through.

Recall covers Nov 2018-Oct 2019 build cars · sources: car-recalls.co.uk (DVSA/SMMT data), MOTCost.co.uk

Keyless entry and stop-start electrical gremlins

Emerging

Owners have reported the key fob going unrecognised, doors locking or unlocking on their own, and the stop-start system refusing to restart the engine, in one case only cured by switching stop-start off altogether. Honest John's own CX-30 file flags these as a recurring theme alongside a temporary shutdown of the safety and driver-support systems. It's shown up on 2020-2021 cars at low mileage, which points to a software or wiring quirk rather than something that wears in with age.

Reported on 2020-21 cars, low mileage · sources: Honest John owner reports, Honest John CX-30 review

Early battery failure / flat 12V battery

Emerging

A handful of owners have reported the battery going flat or failing outright within the first few months, in one case twice before 1,000 miles. The mild-hybrid system and the car's own stop-start electronics ask more of the 12V battery than a conventional car, so one that's already marginal tends to show up sooner. Replacement outside the 3-year warranty runs roughly £150-250.

Reported from new, mostly 2020 cars · sources: Honest John owner reports

Powered tailgate drop / weak retaining force

Powered tailgate trims only

On cars fitted with the powered tailgate, Mazda recalled examples built 2019-2020 because the tailgate could partially lower on its own from fully open. A related report flagged the same tailgate's retaining force as insufficient in hot weather. The fix is free at a dealer under recall; check it's been done and cycle the tailgate a few times at the viewing. Doesn't apply to trims with a manual tailgate.

Recall covers 2019-2020 build cars with powered tailgate · sources: car-recalls.co.uk (DVSA/SMMT data)

Reversing / 360-camera display dropout

Confirmed pattern

A 2023 recall covered cars where the rear-view or 360-degree camera image could fail to appear on the centre screen, put down to a software processing fault, with a related EU recall reported in January 2024 for the same symptom. It's fixed free with a software update under recall. Worth checking the camera comes up cleanly every time reverse is selected, since a dropout on a car that hasn't had the recall done is a known issue, not just bad luck.

Recall reported 2023-24 · sources: car-recalls.co.uk (DVSA/SMMT data)

Viewing one? Ask this

Built from the two sections above.

Run the registration through the DVSA recall checker before you view the car. An outstanding Smart Brake Support, tailgate, or camera recall means a trip to the dealer you shouldn't have to pay for, but it also means the car's had a live safety fault.
Do a slow-speed test drive somewhere open and watch for any unprompted braking. Sudden, unexplained braking with nothing in front of you is the Smart Brake Support fault, recalled or not.
Lock and unlock with the key fob a few times, then try starting with the fob left inside your bag rather than a pocket. A 'key not recognised' message or doors locking themselves points at the reported electrical gremlins.
Sit at idle in gear and let stop-start cut the engine, then try pulling away. Hesitation or a flat refusal to restart is the fault some owners worked around by disabling stop-start entirely.
Ask if the battery has ever been replaced, and check for a recent invoice if so. A battery already swapped once under warranty is a mild flag for a car that draws it down faster than it should.
On cars with a powered tailgate, open it fully and let it sit for a minute before checking it hasn't sagged. Any noticeable drop from fully open is the recalled fault, whether or not the recall's been actioned.
Select reverse and check the camera image appears immediately and stays clean. A blank or garbled screen is the recalled camera display fault, not a one-off electrical blip.

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