Toyota Sienta MOT pass rate & common failures
1,146 MOT tests on the Toyota Sienta (1999–2025) give it a 90.2% pass rate. All cars of a similar age fail 15.9% of the time, so this is 6.1pp better than the group it competes with. Its most common failure areas are lighting & signalling, tyres and visibility.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 9.0% of tests against 2.3% for the next-worst category.
At component level the recurring items are rear fog lamp, headlamp aim and headlamp — rear fog lamp alone was recorded 47 times.
A 150k+ example is materially riskier than a 0-30k one: 20.4% versus 9.0%.
The hybrid cars hold up better: 7.8% fail against 12.2% for petrol, a 4.4-point gap across 1,146 tests.
Suspension is the most common advisory, noted on 14.7% of tests — work that passed today but is likely due soon.
How it compares
By model year
Every Sienta model year with a usable sample. Years with their own detailed report are linked.
| Year | Tests | Pass rate | Fail rate | Most common failure |
|---|---|---|---|---|
| 2005 | 30 | 90.0% | 10.0% | Lighting & signalling |
| 2011 | 33 | 93.9% | 6.1% | Visibility |
| 2015 | 97 | 88.7% | 11.3% | Lighting & signalling |
| 2016 | 236 | 89.4% | 10.6% | Lighting & signalling |
| 2017 | 243 | 90.1% | 9.9% | Lighting & signalling |
| 2018 | 111 | 94.6% | 5.4% | Lighting & signalling |
| 2019 | 97 | 93.8% | 6.2% | Lighting & signalling |
| 2020 | 94 | 85.1% | 14.9% | Lighting & signalling |
| 2021 | 45 | 88.9% | 11.1% | Lighting & signalling |
Most common failures (all years)
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 9.0% | 103 |
| 2 | Tyres | 2.3% | 26 |
| 3 | Visibility | 2.2% | 25 |
| 4 | Suspension | 2.2% | 25 |
| 5 | Brakes | 1.2% | 14 |
| 6 | Body, structure & corrosion | 0.8% | 9 |
| 7 | Road wheels | 0.5% | 6 |
| 8 | Emissions & environmental | 0.4% | 4 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rear fog lamp | 47 |
| 2 | Headlamp aim | 32 |
| 3 | Headlamp | 31 |
| 4 | Position lamp | 27 |
| 5 | Wipers | 19 |
| 6 | Tread depth | 14 |
| 7 | Registration plate lamp(s) | 13 |
| 8 | Pins and bushes | 13 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 14.7% | 168 |
| 2 | Tyres | 11.5% | 132 |
| 3 | Brakes | 6.2% | 71 |
| 4 | Lighting & signalling | 5.8% | 66 |
| 5 | Other defects | 3.4% | 39 |
| 6 | Visibility | 2.5% | 29 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 0-30k | 212 | 9.0% |
| 30-60k | 450 | 7.3% |
| 60-90k | 286 | 9.1% |
| 90-120k | 100 | 14.0% |
| 120-150k | 49 | 20.4% |
| 150k+ | 49 | 20.4% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Hybrid | 639 | 7.8% |
| Petrol | 507 | 12.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 68 | 10.3% |
| 2022 | 130 | 10.8% |
| 2023 | 179 | 8.4% |
| 2024 | 289 | 8.0% |
| 2025 | 480 | 11.0% |
What to check before buying a Toyota Sienta
- Lighting & signalling (9.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Tyres (2.3% of tests): Usually a quick, known-cost fix, but check tread, age and uneven wear (which can hint at alignment or suspension issues). Typical repair: £50–£120 per tyre.
- Visibility (2.2% of tests): Wipers, washers, mirrors and screen damage — usually inexpensive, but check for chips in the driver's line of sight. Typical repair: £15–£150.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
What is the MOT pass rate for the Toyota Sienta?
90.2% of the 1,146 Toyota Sienta MOT tests in this dataset passed, a 9.8% fail rate, across model years 1999–2025.
What does the Toyota Sienta most often fail its MOT on?
Lighting & signalling, recorded in 9.0% of tests, then tyres (2.3%).
How much does mileage affect Sienta MOT results?
Fail rates run at 9.0% for cars in the 0-30k band and 20.4% for 150k+, a 11.5-point difference.
Is the hybrid or petrol Sienta more reliable at MOT time?
On MOT-testable defects the hybrid fails 7.8% of the time against 12.2% for the petrol. This covers testable items only, not engine or gearbox reliability.
Methodology & source. Based on 1,146 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.