2003 Daihatsu Sirion — MOT failures & pass rate
Across 916 MOT tests, the 2003 Daihatsu Sirion recorded a 73.9% pass rate. City cars of a similar age fail 29.4% of the time, so this is 3.3pp better than the group it competes with. Failures cluster in lighting & signalling, suspension and emissions & environmental.
What the MOT record shows
No single area dominates — lighting & signalling (13.3%) and suspension (10.5%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are component mounting prescribed areas, catalyst emissions and malfunction indicator lamp — component mounting prescribed areas alone was recorded 119 times.
Mileage is the strongest signal on the record: 14.5% of 0-30k cars fail, rising to 37.5% once past 120-150k — 2.6× the risk.
Suspension is the most common advisory, noted on 34.5% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 27.5% in 2021 to 25.2% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 13.3% | 122 |
| 2 | Suspension | 10.5% | 96 |
| 3 | Emissions & environmental | 9.2% | 84 |
| 4 | Brakes | 9.2% | 84 |
| 5 | Body, structure & corrosion | 7.9% | 72 |
| 6 | Visibility | 6.2% | 57 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Component mounting prescribed areas | 119 |
| 2 | Catalyst emissions | 52 |
| 3 | Malfunction indicator lamp | 47 |
| 4 | Position lamp | 46 |
| 5 | Wipers | 45 |
| 6 | Exhaust system | 44 |
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 | 34.5% | 316 |
| 2 | Brakes | 27.8% | 255 |
| 3 | Tyres | 23.5% | 215 |
| 4 | Lighting & signalling | 19.1% | 175 |
| 5 | Other defects | 18.1% | 166 |
| 6 | Body, structure & corrosion | 13.4% | 123 |
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 | 83 | 14.5% |
| 30-60k | 274 | 25.9% |
| 60-90k | 374 | 24.9% |
| 90-120k | 129 | 33.3% |
| 120-150k | 48 | 37.5% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 247 | 27.5% |
| 2022 | 211 | 24.6% |
| 2023 | 187 | 24.1% |
| 2024 | 152 | 28.9% |
| 2025 | 119 | 25.2% |
What to check before buying a 2003 Sirion
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 13.3% of tests. Start there.
- Lighting & signalling (13.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (10.5% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Emissions & environmental (9.2% of tests): More common on older diesels (DPF/EGR) — can be expensive; check for warning lights and smoke. Typical repair: £100–£600.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 2003 Daihatsu Sirions pass their MOT?
73.9% of the 916 2003 Daihatsu Sirion MOT tests in this dataset passed — a 26.1% fail rate.
What is the most common MOT failure on a 2003 Daihatsu Sirion?
Lighting & signalling, recorded in 13.3% of tests, followed by suspension (10.5%).
Does the 2003 Sirion get worse with mileage?
Its MOT fail rate rises from 14.5% in the 0-30k band to 37.5% in the 120-150k band.
Methodology & source. Based on 916 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.