Model Reports 4 min read Updated 18 Oct 2026

Toyota Prius 2012: reliability & common MOT faults

In 2025, 72 in every 100 first MOTs on a 2012 Toyota Prius were passes. Most common reason for a fail: Individual sidelight or tail light (front).

Summary

The 2012 Toyota Prius follows the pattern of the model years either side.

At a glance

How 7,189 first tests went in 2025.

Passed first time
72 in every 100
Did not pass first time
28 in every 1002,024 failed first-attempt tests
The typical car
13 yearsabout 168,169 miles
First tests counted
7,189

What failed most often

  1. Individual sidelight or tail light (front)15 in every 100 failed tests
  2. Number plate lights (rear)11 in every 100 failed tests
  3. Headlight (front)8 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Note:

These are patterns across 2012 Toyota Prius vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Lamps and electrical

Two faults. The strongest is the number plate lights (rear): 3.6 times as often as on similar cars.

Figures below are measured across the 2,019 of 2,024 failed first attempts (99.8%) that recorded an odometer reading in 2025. Mileage is needed to compare like with like.

We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.

Number plate lights (rear)

Failed on 213 first tests3.6 times as often as similar carsLikely evidence

What it means

Registration plate lamps must light up the rear registration plate and operate at the same time as the position lamps. A missing or inoperative lamp is Major when the plate has only one lamp or all its lamps are not working, and Minor when the plate has several lamps or light sources and not all have failed. A lamp throwing direct white light to the rear is also Minor.

Rear fog light

Failed on 93 first tests2.9 times as often as similar carsPossible evidence

What it means

A missing obligatory rear fog lamp, one that is not working, or one that does not emit a steady red light is graded Major. A rear fog lamp adversely affected by the operation of any other lamp is Major too. The manual allows it to go out when main beam is switched on or when dipped beam headlamps are switched off.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Visibility

One fault: windscreen wipers (front), 2.6 times as often as on similar cars.

Windscreen wipers (front)

Failed on 126 first tests2.6 times as often as similar carsPossible evidence

What it means

Only a clearly damaged or worn windscreen wiper needs to be rejected. A wiper that is missing or not working is graded Major, and so is a blade that is missing or obviously not clearing the windscreen. A defective blade is graded Minor.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail.

Steering rack play

Noted on 42 first tests5.4 times as often as similar carsElevated evidence

Headlight (front)

Noted on 72 first tests3.8 times as often as similar carsElevated evidence

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time
72in every 100
Passed on the first test.
Fixed at the station
11in every 100
Failed, then fixed at the test station the same day.
Failed
17in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 71.8% of 7,189 first tests (2025): only cars that passed first time count. Official-style pass 82.7%: cars fixed at the test station also count as a pass. The 11 fixed and the 17 not fixed make the 28 in every 100 that did not pass first time.

Same model, other years

Passed first time in every 100, all tested in 2025.

4060801002005201220152020Older carsNewer cars
40608010020122020Older carsNewer cars

Newer cars are younger, so look for a jump rather than the climb.

YearPassed first timeFirst tests
200461 in every 100718
200562 in every 1001,997
200660 in every 1003,011
200763 in every 1005,787
200864 in every 1005,840
200965 in every 1006,052
201067 in every 1008,502
201168 in every 1006,402
2012 This car72 in every 1007,189
201373 in every 1007,387
201477 in every 1008,789
201578 in every 1008,452
201683 in every 1009,674
201786 in every 10010,100
201888 in every 10010,102
201987 in every 10011,080
202088 in every 1007,409
202191 in every 1002,167
202292 in every 1001,166

If you are buying one

What this year's MOT record means for the decision in front of you.

Mileage matters most on a 2012 Prius.

Of 2012 Prius vehicles with under 85,000 miles, 78 in every 100 passed their 2025 MOT first time. With 258,000 miles or more, 69 in every 100 did.

Under 85,0001,436 tests
78
85,000–136,0001,443 tests
72
136,000–199,000 Typical car1,436 tests
69
199,000–258,0001,421 tests
71
258,000 and over1,444 tests
69

What to check at your mileage

How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.

Under 85,000136,000–199,000258,000 and over
Individual sidelight or tail light (front)1.94.75.6
Number plate lights (rear)1.93.03.6
Headlight (front)1.72.43.2
Tyre tread depth (front)1.32.12.3
Anti-roll bar linkage ball joint dust cover (front)2.12.21.1

Faults per 100 first tests, by the car's mileage at the test.

When a car fails

33in every 100

of failed cars had one item to fix.

42in every 100

of failed cars had three or more items to fix.

6in every 100

of all first tests had a defect the tester marked dangerous (unsafe to drive away).

Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. MOTs do not test engine or gearbox internals, so this is a pre-purchase checklist, not a full reliability score.

FAQs

Short answers about how to read this model-year guide.

The 2012 Toyota Prius follows the pattern of the model years either side. Its main cause of failure was Individual sidelight or tail light (front), about 15 in every 100 failed tests. In 2025, 71.8% of 7,189 first MOTs on the 2012 Toyota Prius passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 82.7%. Among 2,024 failed first-attempt MOT tests (test year 2025), Number plate lights (rear) appears more often than on similar cars (10.5% of those tests; 213 observed failures; about 3.6× more often than similar cars). There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.
Ranked by how often they were actually recorded, the items that most often failed a 2012 Toyota Prius at the first attempt were Individual sidelight or tail light (front) (15.3%), Number plate lights (rear) (10.5%) and Headlight (front) (8.3%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Number plate lights (rear) (10.5% of those tests; 213 observed failures; about 3.6× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Number plate lights (rear) shows up more often than on similar cars (10.5% of those tests; 213 observed failures; about 3.6× more often than similar cars). That does not prove a design fault. Age, mileage, and how the car was used still matter. Treat it as a pre-purchase checkpoint, not a manufacturer service bulletin.
Common MOT problem areas for the 2012 Toyota Prius include Number plate lights (rear), Rear fog light, Windscreen wipers (front). These are the faults that stand out compared with similar cars, not a complete list of what can go wrong on any individual car.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2012 Toyota Prius (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics, not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars, not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics; this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces, but does not remove, differences in how cars were used and maintained.
  • If the data for a car is too thin to say anything useful, we say so rather than guess.

Contains public sector information licensed under the Open Government Licence v3.0.

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