Model Reports
8 min readUpdated 11 Sep 2026
DVSA open data · 48,623 tests analysed
Mercedes-Benz A-Class 2019: reliability & common MOT faults
7,207 first-attempt MOT failures were recorded on the 2019 Mercedes-Benz A-Class in 2025. The items recorded most often on them were Tread depth (front) and Tyres — Condition (front). Figures are among first-attempt failed MOT tests, not among all tests.
Petrol A-Class passed first time 2.6 pp more often than diesel ones (86.2% of 29,783 vs 83.6% of 18,834).
First-attempt pass
85.2%
of 48,623 first tests (2025)
First tests
48,623
test year 2025
Failed first attempts
7,207
failed first-attempt tests
Most common fail
14.3%
Tread depth (front)
MOT pass rates
First-attempt and official-style rates among class 4 first tests of the year.
First-attempt pass
85.2%
of 48,623 first tests (2025)
Official-style pass
87.5%
incl. same-day PRS fixes
First tests
48,623
class 4 · first MOT of the year
Typical age 6.0 yrs · median mileage 45,730 mi
vs 2024:
-0.5 pp first-attempt
Note:
Class 4 cars · first MOT of the year per vehicle · P/PRS/F outcomes (2025 data).
PRS (fixed at the station the same day) counts as a fail in the first-attempt rate.
Raw outcomes for this cohort — not adjusted for age, mileage, or peer mix.
MOT doesn't test engine or gearbox internals.
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.
Shares below are measured across the 7,195 of
7,207 failed first attempts
(99.8%) that recorded an odometer reading in 2025 —
the subset the age-and-mileage comparison can be computed on.
Standout: SRS malfunction indicator lamp — 13.4% of this year's failed first attempts
Recorded on 966 of those tests. It tops the table on elevation — about 16× more often than on similar cars of the same age and mileage. That is what makes it unusual for its class, which is a different question from what is most likely to fail; the buying checklist ranks by that. The full ranked list is in the table below.
Fault pattern
Location
Failures
vs similar cars
Share of fails
Confidence
SRS malfunction indicator lamp
Seat belts and supplementary restraint systems > SRS malfunction indicator lamp
Any
966
×16
13.4%
Strong
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.
Advisories
Notes recorded at the test that appear more often than on similar cars.
Advisory notes recorded on failed first-attempt tests that appear more often than on similar cars.
Advisory pattern
Location
Notes
vs similar cars
Share
Confidence
Ball joint (front)
Suspension > Suspension arms > Ball joint
Front
274
×4.8
3.8%
Elevated
Ball joint (front)
Suspension > Anti-roll bars > Ball joint
Front
23
×4.5
0.3%
Possible
Wheel bearings (rear)
Suspension > Wheel bearings
Rear
35
×4.3
0.5%
Elevated
Hydraulic systems — Reservoirs
Brakes > Hydraulic systems > Reservoirs
Any
22
×2.9
0.3%
Elevated
Brake fluid
Brakes > Hydraulic systems > Brake fluid
Any
34
×2.3
0.5%
Elevated
Note: Advisories are not a fail rate — they flag issues noted at the test, often before they become failures.
If you are buying one
What this year's MOT record means for the decision in front of you.
On this year, prefer the petrol. The diesel cars passed first time 2.6 pp less often, on 18,834 tests.
Other A-Class years worth knowing about
Newer cars always pass more often, so a plain "best year" list would just
rank by age. These are the years that beat or miss the trend their own
neighbouring years set — the only age-adjusted signal this data supports.
The items that failed 2019 A-Class most
often, as a share of the year's failed first attempts. This is what goes
wrong, not what is unusual — the table further up the page covers that.
Tread depth (front) — recorded on 14.3% of failed first attempts
Tyres — Condition (front) — recorded on 13.9% of failed first attempts
SRS malfunction indicator lamp — recorded on 13.4% of failed first attempts
Brake pads (rear) — recorded on 10.7% of failed first attempts
Every figure here is a first-attempt MOT rate from DVSA open data for this
model line. MOTs do not test engine or gearbox internals, so this is a
pre-purchase checklist, not a full reliability score.
FAQs
Short answers about how to read this model-year guide.
Petrol A-Class passed first time 2.6 pp more often than diesel ones (86.2% of 29,783 vs 83.6% of 18,834). In 2025, 85.2% of 48,623 first MOTs on the 2019 Mercedes-Benz A-Class passed first time (PRS — items fixed at the station the same day — counted as a fail). The official-style rate including PRS is 87.5%. Among 7,207 failed first-attempt MOT tests (test year 2025), SRS malfunction indicator lamp appears more oft…
Ranked by how often they were actually recorded, the items that failed 2019 Mercedes-Benz A-Classs most often at the first attempt were Tread depth (front) (14.3%), Tyres — Condition (front) (13.9%) and SRS malfunction indicator lamp (13.4%) — each as a share of the year's failed first attempts. That is what goes wrong on the car. It is a different question from which patterns are unusual for the class, which the co…
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: SRS malfunction indicator lamp (13.4% of those tests; 966 observed failures; about 16× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
SRS malfunction indicator lamp shows up more often than on similar cars (13.4% of those tests; 966 observed failures; about 16× more often than similar cars). 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 2019 Mercedes-Benz A-Class include SRS malfunction indicator lamp. 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.
Advisories flag issues noted at the test and are not a fail rate. We show advisory patterns that appear more often than on similar cars among failed first-attempt tests, separate from common failure rows. Use them as early-warning checks, not as a pass/fail score.
This page highlights MOT failure patterns for the 2019 Mercedes-Benz A-Class (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.
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.
20242025
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.