What are the most common problems with a 2021 Toyota Prius hybrid?

Known faults on the 2021 Toyota Prius hybrid include fire-risk and parking brake recalls. The biggest MOT weak spot is rear fog light: flagged on 2.8% of tests, 9.3× the rate for all 2021 cars, followed by number plate lights (3.1%).

What should I ask the seller before buying a used 2021 Toyota Prius hybrid?

Have all the recalls been done, including the 2018 fire-risk one? Any recent work on the rear fog light? (Flagged at MOT 9.3× as often on the 2021 Toyota Prius hybrid as on other cars the same age.) Any recent work on the number plate lights? (Flagged at MOT 5.2× as often on the 2021 Toyota Prius hybrid as on other cars the same age.) Can I see the service history and receipts for any big jobs?

Part of the Toyota Prius Mk4 (2016–2022) guide: best and worst years compared.

Used car guide

2021 Toyota Prius hybrid: common problems and MOT failures

What MOT testers find on the hybrid Toyota Prius first registered in 2021 (hybrid cars only): we looked at the 1,145 MOTs these cars had during 2023–2025. Plus known faults and what to look at before you buy one.

1,145MOTs of 2021 hybrid cars, done in 2023–2025

87%pass first time (all 2021 cars: 87%)

27,000typical miles a year

9.3×the usual rate for rear fog light

What goes wrong more than usual on a 2021 Toyota Prius hybrid?

Parts flagged at MOT more often on the 2021 Toyota Prius hybrid than on all cars registered in 2021.

Rear fog light9.3× usual

Toyota Prius
2.8% All 2021 cars
0.3%

Failed outright at MOT: 2.7%, against 0.3% of all 2021 cars. The rest were advisories or minor defects.

Rough price £10–£80 our estimate

At the viewing: Ask a friend to check every light while you work the switches: indicators, brake lights, fog lights and reversing lights.
Number plate lights5.2× usual

Toyota Prius
3.1% All 2021 cars
0.6%

Failed outright at MOT: 1.7%, against 0.2% of all 2021 cars. The rest were advisories or minor defects.

Rough price £5–£40 our estimate

At the viewing: Check the number plate lights work and the plates are clean and legal.

Common 2021 Toyota Prius hybrid MOT failures and advisories

The share of 2021 Toyota Prius hybrid MOT tests where testers flagged each area, as a fail or an advisory. Rough prices are typical independent-garage costs.

Tyres

17% of testsRough price £70–£150

At the viewing: Check the tread on all four tyres, including the inside edges, and look for cracks or bulges.
Lights and electrics

8% of testsRough price £10–£80

At the viewing: Ask a friend to check every light, including brake lights and indicators, while you operate them.
Brakes

4% of testsRough price £150–£350

At the viewing: Look for a lip on the disc edges and feel for judder or pulling when braking firmly from about 40mph.
Suspension

4% of testsRough price £120–£400

At the viewing: Listen for knocks over speed bumps, and look behind each front wheel for a snapped coil spring.
Wipers, windscreen and mirrors

3% of testsRough price £15–£250

At the viewing: Check for chips in the driver's view, and test the wipers and washers.
Steering

1% of testsRough price £100–£450

At the viewing: On a straight road the steering wheel should sit straight. Feel for play or knocking when turning.

Known faults on the 2021 Toyota Prius hybrid

Reported by owners, mechanics and buying guides for this model and age. Check which engine the car has, as some apply to one engine only.

Fire-risk and parking brake recalls
All versions
About 32,000 UK cars were recalled in 2018 for a possible fire risk, and others for the parking brake (2016), passenger airbags and an ECU check (2020).

At the viewing: Ask a Toyota dealer to check the VIN for outstanding recalls.

Source: Auto Express: used Toyota Prius (Mk4, 2015-2022) review

Questions to ask the seller before buying a 2021 Toyota Prius hybrid

Ask before you travel to see it. A seller who knows the car will have answers, and receipts.

Have all the recalls been done, including the 2018 fire-risk one?
Any recent work on the rear fog light? (Flagged at MOT 9.3× as often on the 2021 Toyota Prius hybrid as on other cars the same age.)
Any recent work on the number plate lights? (Flagged at MOT 5.2× as often on the 2021 Toyota Prius hybrid as on other cars the same age.)
Can I see the service history and receipts for any big jobs?

Looking at a Toyota Prius?

Check the actual car: its own MOT history, mileage and what to ask the seller. Free, no sign-up.

Other years

Every year of the Toyota Prius compared

Year	MOT tests	Most flagged
2026	–	Too new for MOT data
2025	–	Too new for MOT data
2024	–	Too new for MOT data
2023	1,232	Tyres 16%
2022	2,834	Tyres 16%
2020	26,304	Tyres 18%
2019	47,795	Tyres 16%
2018	42,725	Tyres 16%
2017	45,148	Tyres 17%
2016	43,989	Tyres 18%
2015	40,082	Tyres 17%
2014	35,918	Tyres 20%
2013	26,198	Lights and electrics 22%
2012	23,311	Lights and electrics 24%
2011	21,036	Lights and electrics 31%
2010	28,189	Lights and electrics 33%
2009	20,260	Lights and electrics 35%
2008	19,495	Lights and electrics 39%
2007	19,325	Lights and electrics 40%
2006	10,324	Lights and electrics 43%
2005	6,989	Lights and electrics 44%
2004	2,573	Lights and electrics 47%
2003	406	Suspension 46%
2002	129	Suspension 46%
2001	227	Suspension 42%
2000	–	Too few tests

Where this comes from: the DVSA's anonymised results for every MOT test done in Great Britain during 2023–2025, counting the MOTs of Toyota Prius cars first registered in 2021. "Flagged" includes advisories, so it isn't the same as a fail rate. How we score