2003 Mercedes-Benz A-Class — MOT failures & pass rate
The 2003 Mercedes-Benz A-Class passed 71.7% of its 11,674 recorded MOT tests. Small family cars of a similar age fail at 28.1%, so the 2003 A-Class sits squarely on the average. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
No single area dominates — lighting & signalling (17.2%) and suspension (15.3%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are rigid brake pipes, headlamp aim and coil spring — rigid brake pipes alone was recorded 903 times.
Mileage is the strongest signal on the record: 23.9% of 0-30k cars fail, rising to 32.7% once past 150k.
Split by fuel, diesel examples fail 1.6pp more often than petrol ones (29.7% vs 28.1%) — worth weighing if you have a choice.
Advisories point at the next bill rather than this one: brakes was flagged on 47.0% of tests without failing them.
The trend is improving — the fail rate fell from 29.2% in 2021 to 27.4% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 17.2% | 2,011 |
| 2 | Suspension | 15.3% | 1,780 |
| 3 | Brakes | 10.4% | 1,220 |
| 4 | Visibility | 8.7% | 1,018 |
| 5 | Tyres | 5.6% | 657 |
| 6 | Emissions & environmental | 4.7% | 550 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rigid brake pipes | 903 |
| 2 | Headlamp aim | 873 |
| 3 | Coil spring | 831 |
| 4 | Stop lamp | 665 |
| 5 | Headlamp | 636 |
| 6 | Washers | 604 |
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 | 47.0% | 5,492 |
| 2 | Suspension | 34.5% | 4,023 |
| 3 | Tyres | 26.7% | 3,111 |
| 4 | Other defects | 20.9% | 2,443 |
| 5 | Lighting & signalling | 16.7% | 1,945 |
| 6 | Body, structure & corrosion | 10.1% | 1,183 |
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 | 553 | 23.9% |
| 30-60k | 2,128 | 23.0% |
| 60-90k | 4,187 | 27.4% |
| 90-120k | 2,830 | 31.3% |
| 120-150k | 902 | 31.4% |
| 150k+ | 211 | 32.7% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 10,116 | 28.1% |
| Diesel | 1,558 | 29.7% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 3,851 | 29.2% |
| 2022 | 2,840 | 28.0% |
| 2023 | 2,163 | 28.5% |
| 2024 | 1,586 | 27.4% |
| 2025 | 1,234 | 27.4% |
What to check before buying a 2003 A-Class
On a 2003 A-Class, lighting & signalling is what the MOT record says goes wrong most — it appeared in 17.2% of tests. Check these areas before you commit.
- Lighting & signalling (17.2% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (15.3% 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.
- Brakes (10.4% 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 Mercedes-Benz A-Classs pass their MOT?
71.7% of the 11,674 2003 Mercedes-Benz A-Class MOT tests in this dataset passed — a 28.3% fail rate.
What is the most common MOT failure on a 2003 Mercedes-Benz A-Class?
Lighting & signalling, recorded in 17.2% of tests, followed by suspension (15.3%).
Does the 2003 A-Class get worse with mileage?
Its MOT fail rate rises from 23.9% in the 0-30k band to 32.7% in the 150k+ band.
Methodology & source. Based on 11,674 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.