2014 Mercedes-Benz Viano — MOT failures & pass rate
Across 4,151 MOT tests, the 2014 Mercedes-Benz Viano recorded an 80.3% pass rate. That is 1.6 percentage points worse than all cars of a similar age, which fail at 18.2%. Failures cluster in lighting & signalling, brakes and tyres.
What the MOT record shows
No single area dominates — lighting & signalling (10.5%) and brakes (7.8%) are close, so failures are spread across several systems rather than one weak point.
At component level the recurring items are rbt (sp), tread depth and side repeaters — rbt (sp) alone was recorded 170 times.
Condition tracks the odometer closely. Failures run at 10.3% in the 0-30k band and 19.6% in the 150k+ band, a 9.3-point spread.
Tyres is the most common advisory, noted on 25.5% of tests — work that passed today but is likely due soon.
The trend is worsening — 18.6% of tests failed in 2021 against 22.3% in 2025, the usual pattern as a fleet ages.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 10.5% | 436 |
| 2 | Brakes | 7.8% | 323 |
| 3 | Tyres | 5.8% | 239 |
| 4 | Emissions & environmental | 3.7% | 155 |
| 5 | Suspension | 3.7% | 153 |
| 6 | Visibility | 3.1% | 130 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Rbt (sp) | 170 |
| 2 | Tread depth | 140 |
| 3 | Side repeaters | 134 |
| 4 | Headlamp aim | 118 |
| 5 | Position lamp | 96 |
| 6 | Parking brake performance | 81 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Tyres | 25.5% | 1,057 |
| 2 | Brakes | 19.8% | 822 |
| 3 | Suspension | 14.2% | 590 |
| 4 | Other defects | 8.2% | 341 |
| 5 | Lighting & signalling | 7.2% | 300 |
| 6 | Body, structure & corrosion | 6.8% | 280 |
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 | 145 | 10.3% |
| 30-60k | 516 | 16.5% |
| 60-90k | 745 | 21.1% |
| 90-120k | 777 | 21.5% |
| 120-150k | 672 | 21.0% |
| 150k+ | 1,291 | 19.6% |
Failure rate by age
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 874 | 18.6% |
| 2022 | 865 | 19.5% |
| 2023 | 836 | 19.1% |
| 2024 | 792 | 19.3% |
| 2025 | 784 | 22.3% |
What to check before buying a 2014 Viano
The failure pattern for this year is specific enough to inspect against: lighting & signalling accounted for 10.5% of tests. Start there.
- Lighting & signalling (10.5% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Brakes (7.8% 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.
- Tyres (5.8% 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.
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 2014 Mercedes-Benz Vianos pass their MOT?
80.3% of the 4,151 2014 Mercedes-Benz Viano MOT tests in this dataset passed — a 19.8% fail rate.
What is the most common MOT failure on a 2014 Mercedes-Benz Viano?
Lighting & signalling, recorded in 10.5% of tests, followed by brakes (7.8%).
Does the 2014 Viano get worse with mileage?
Its MOT fail rate rises from 10.3% in the 0-30k band to 19.6% in the 150k+ band.
Methodology & source. Based on 4,151 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.