2003 Mazda B Series — MOT failures & pass rate
1,898 MOT tests on the 2003 Mazda B Series are in this dataset, and 71.3% of them passed. Against all cars of a similar age (27.7% fail rate), the 2003 B Series comes out 1.1pp worse. Failures cluster in lighting & signalling, body, structure & corrosion and brakes.
What the MOT record shows
One area stands out: lighting & signalling, recorded in 20.0% of tests against 13.7% for the next-worst category.
At component level the recurring items are rear fog lamp, rigid brake pipes and joints — rear fog lamp alone was recorded 164 times.
Mileage is the strongest signal on the record: 15.6% of 30-60k cars fail, rising to 30.6% once past 150k.
Brakes is the most common advisory, noted on 38.8% of tests — work that passed today but is likely due soon.
The trend is improving — the fail rate fell from 29.3% in 2021 to 27.8% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 20.0% | 379 |
| 2 | Body, structure & corrosion | 13.7% | 259 |
| 3 | Brakes | 12.4% | 236 |
| 4 | Suspension | 12.4% | 236 |
| 5 | Visibility | 5.8% | 110 |
| 6 | Emissions & environmental | 4.0% | 75 |
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 | 164 |
| 2 | Rigid brake pipes | 151 |
| 3 | Joints | 140 |
| 4 | Headlamp aim | 138 |
| 5 | Position lamp | 106 |
| 6 | Headlamp | 100 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Brakes | 38.8% | 737 |
| 2 | Body, structure & corrosion | 33.6% | 637 |
| 3 | Suspension | 30.8% | 584 |
| 4 | Tyres | 19.2% | 364 |
| 5 | Other defects | 16.4% | 311 |
| 6 | Lighting & signalling | 15.7% | 298 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 122 | 15.6% |
| 60-90k | 345 | 27.3% |
| 90-120k | 467 | 30.2% |
| 120-150k | 475 | 30.7% |
| 150k+ | 451 | 30.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 498 | 29.3% |
| 2022 | 437 | 29.3% |
| 2023 | 371 | 28.8% |
| 2024 | 304 | 27.6% |
| 2025 | 288 | 27.8% |
What to check before buying a 2003 B Series
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 20.0% of tests. Start there.
- Lighting & signalling (20.0% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Body, structure & corrosion (13.7% of tests): The one to take seriously on older cars — corrosion to structural areas can be costly and is an MOT failure. Typical repair: £200–£1,500+.
- Brakes (12.4% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
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 Mazda B Seriess pass their MOT?
71.3% of the 1,898 2003 Mazda B Series MOT tests in this dataset passed — a 28.7% fail rate.
What is the most common MOT failure on a 2003 Mazda B Series?
Lighting & signalling, recorded in 20.0% of tests, followed by body, structure & corrosion (13.7%).
Does the 2003 B Series get worse with mileage?
Its MOT fail rate rises from 15.6% in the 30-60k band to 30.6% in the 150k+ band.
Methodology & source. Based on 1,898 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.