2009 Mercedes-Benz A-Class — MOT failures & pass rate
Across 46,758 MOT tests analysed for the 2009 Mercedes-Benz A-Class, the most common recorded failure areas were lighting & signalling, suspension and brakes. Its pass rate of 76.3% was above the average for small family cars of a similar age (74.6%). Higher-mileage examples failed more often — 31.9% in the 150k+ group versus 11.6% in the 0-30k group.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 11.9% | 5,574 |
| 2 | Suspension | 8.8% | 4,116 |
| 3 | Brakes | 8.7% | 4,066 |
| 4 | Visibility | 6.2% | 2,908 |
| 5 | Tyres | 4.1% | 1,921 |
| 6 | Body, structure & corrosion | 4.0% | 1,888 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 2,882 |
| 2 | Rigid brake pipes | 2,473 |
| 3 | Washers | 2,322 |
| 4 | Coil spring | 1,825 |
| 5 | Shock absorbers | 1,591 |
| 6 | Ball joint | 1,468 |
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 | 39.8% | 18,611 |
| 2 | Tyres | 27.7% | 12,927 |
| 3 | Suspension | 17.5% | 8,200 |
| 4 | Other defects | 13.4% | 6,244 |
| 5 | Lighting & signalling | 7.9% | 3,690 |
| 6 | Body, structure & corrosion | 7.5% | 3,518 |
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 | 1,623 | 11.6% |
| 30-60k | 11,509 | 19.0% |
| 60-90k | 17,350 | 23.8% |
| 90-120k | 10,925 | 27.2% |
| 120-150k | 4,031 | 29.3% |
| 150k+ | 1,305 | 31.9% |
Failure rate by age
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 32,452 | 22.9% |
| Diesel | 14,306 | 25.4% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 9,947 | 21.8% |
| 2022 | 9,762 | 22.5% |
| 2023 | 9,535 | 23.8% |
| 2024 | 9,025 | 24.7% |
| 2025 | 8,489 | 26.2% |
What to check before buying a 2009 A-Class
Before buying a 2009 Mercedes-Benz A-Class, focus on the areas it most often fails on. Lighting & signalling accounted for 11.9% of tests for this year.
- Lighting & signalling (11.9% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (8.8% 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 (8.7% 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 2009 Mercedes-Benz A-Classs pass their MOT?
76.3% of the 46,758 2009 Mercedes-Benz A-Class MOT tests in this dataset passed — a 23.7% fail rate.
What is the most common MOT failure on a 2009 Mercedes-Benz A-Class?
Lighting & signalling, recorded in 11.9% of tests, followed by suspension (8.8%).
Does the 2009 A-Class get worse with mileage?
Its MOT fail rate rises from 11.6% in the 0-30k band to 31.9% in the 150k+ band.
Methodology & source. Based on 46,758 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-01. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.