Model Reports 8 min read Updated 13 Jul 2026

Mercedes-Benz Cla 2015: reliability & common MOT faults

On the 2015 Mercedes-Benz Cla, MOT failures for SRS malfunction indicator lamp and Linkage ball joint dust cover (front) show up more often than on similar cars of the same age and mileage. Figures come from UK DVSA open data for tests in 2025 (1,725 failed first-attempt tests). Figures are among first-attempt failed MOT tests, not among all tests.

Sample

1,725 failed first-attempt tests · 6,449 first tests (test year 2025)

Standout pattern

SRS malfunction indicator lamp — about 7.4× more often than on similar cars.

What to check

  • SRS malfunction indicator lamp — about 7.4× more often than similar cars
  • Linkage ball joint dust cover (front) — about 5.2× more often than similar cars
  • Road Wheels — Condition (front) — about 13× more often than similar cars

Common faults

Failure patterns that show up more often on this registration year than on similar cars.

These MOT failure patterns show up more often on this registration year than on similar cars of the same class, age, and mileage.

Based on 1,725 failed first-attempt tests in 2025.

SRS malfunction indicator lamp

This failure pattern appears about 7.4× more often than on similar cars — recorded on 138 failed first-attempt tests; 8.0% of failed tests for this model year.

Any 138 failures ×7.4 8.0% of failed first tests Strong

Linkage ball joint dust cover (front)

This failure pattern appears about 5.2× more often than on similar cars — recorded on 183 failed first-attempt tests; 10.6% of failed tests for this model year.

Front 183 failures ×5.2 10.6% of failed first tests Strong

# Fault pattern Location Failures vs similar cars Share of fails Confidence
1 Road Wheels — Condition (front)
Road Wheels > Condition
 Front 37 ×13 2.1% Likely
2 SRS malfunction indicator lamp
Seat belts and supplementary restraint systems > SRS malfunction indicator lamp
 Any 138 ×7.4 8.0% Strong
3 Ball joint dust cover (front)
Suspension > Anti-roll bars > Ball joint dust cover
 Front 90 ×6.5 5.2% Likely
4 Linkage ball joint dust cover (front)
Suspension > Anti-roll bars > Linkage ball joint dust cover
 Front 183 ×5.2 10.6% Strong
5 Coil spring (rear)
Suspension > Springs > Coil springs > Coil spring
 Rear 314 ×3.3 18.2% Likely
6 Malfunction indicator lamp
Noise, emissions and leaks > Exhaust emissions > Spark ignition > Malfunction indicator lamp
 Any 116 ×2.1 6.7% Possible

Only patterns that clear minimum sample and elevation thresholds are shown (at least 20 failures and about 2.0× more often than similar cars).

Note: Rates and comparisons are among first-attempt failed tests, not all MOTs. Patterns come from MOT defect codes — not manufacturer service bulletins, recalls, or a diagnosis of any individual car. Failures and advisories are listed separately.

FAQs

Short answers about how to read this model-year guide.

We do not show a single reliability score for the 2015 Mercedes-Benz Cla on this page. Among 1,725 failed first-attempt MOT tests (test year 2025), SRS malfunction indicator lamp appears more often than on similar cars (about 7.4× more often than similar cars; 138 observed failures; 8.0% of failed tests). Treat this as a pre-purchase checklist from DVSA open data — not a guarantee for any individual car.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: SRS malfunction indicator lamp (about 7.4× more often than similar cars; 138 observed failures; 8.0% of failed tests). These are statistical signals, not a diagnosis of any individual car.
SRS malfunction indicator lamp shows up more often than on similar cars (about 7.4× more often than similar cars; 138 observed failures; 8.0% of failed tests). That does not prove a design fault — age, mileage, and how the car was used still matter. Treat it as a pre-purchase check point, not a manufacturer service bulletin.
Common MOT problem areas for the 2015 Mercedes-Benz Cla include SRS malfunction indicator lamp, Linkage ball joint dust cover (front), Road Wheels — Condition (front). These patterns show up more often than on similar cars after we filter out sparse noise — not a full list of every possible fault on an individual car.
This page highlights MOT failure patterns for the 2015 Mercedes-Benz Cla (registration year) using UK DVSA open data for the selected test year. Patterns are compared with cars of a similar age and mileage. It is a buyer checklist from MOT defect statistics — not a full service history or manufacturer service-bulletin list.
No. MOT tests do not cover engine internals, gearboxes, or many electronic modules. Patterns here come from MOT defect statistics only and should not be read as engine or gearbox reliability scores.
PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.
We count how often each MOT defect pattern appears among failed first-attempt tests for this model year, then compare that with similar cars. We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself. A higher multiple means the pattern shows up more often than expected for similar car…

About this data

How this page is built and what it can (and can't) say.

These figures come from UK MOT open data for this model year. We surface common failure patterns against similar cars — not a full reliability score, and not a pass/fail verdict on any individual vehicle.

2024 2025

What we include

UK Class 4 cars only. Normal MOT tests (not retests); first test per vehicle per calendar year; results pass, PRS, or fail.

Same-day repairs

PRS means the car failed items that were fixed at the test station and then passed the same day. We count PRS as a first-attempt fail in headline rates so same-day repairs do not hide problems.

How we compare

We compare this model year with other Class 4 cars of similar age and mileage in the same test year. This model family is left out of the peer group so the car is not measured against itself.

What this does not cover

  • MOTs do not cover engine internals, gearboxes, or many electronics — this is not a full reliability score.
  • Common faults come from MOT defect stats, not manufacturer TSBs or recalls.
  • Age and mileage matching reduces — but does not remove — differences in how cars were used and maintained.
  • We never invent pass rates, star scores, or ranks when those data marts are missing.

Contains public sector information licensed under the Open Government Licence v3.0.

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See brand-wide MOT rankings and year guidance for Mercedes-Benz (separate from this model-year report).