Model Reports
8 min readUpdated 11 Sep 2026
DVSA open data · 3,017 tests analysed
Isuzu D-Max 2021: reliability & common MOT faults
532 first-attempt MOT failures were recorded on the 2021 Isuzu D-Max in 2025. Figures are among first-attempt failed MOT tests, not among all tests.
Shock absorbers (rear) was the most common reason a 2021 D-Max failed its MOT — 15.1% of its failed first attempts.
First-attempt pass
82.4%
of 3,017 first tests (2025)
First tests
3,017
test year 2025
Failed first attempts
532
failed first-attempt tests
MOT pass rates
First-attempt and official-style rates among class 4 first tests of the year.
First-attempt pass
82.4%
of 3,017 first tests (2025)
Official-style pass
87.0%
incl. same-day PRS fixes
First tests
3,017
class 4 · first MOT of the year
Typical age 4.0 yrs · median mileage 45,188 mi
vs 2024:
-0.6 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 529 of
532 failed first attempts
(99.4%) that recorded an odometer reading in 2025 —
the subset the age-and-mileage comparison can be computed on.
Standout: Shock absorbers (rear) — 15.1% of this year's failed first attempts
Recorded on 80 of those tests. It tops the table on elevation — about 12× more often than on similar cars of the same age and mileage. On this year it is also the commonest failure, so it answers both questions at once. The full ranked list is in the table below.
No patterns met the strongest callout thresholds on this page; showing the highest-lift
rows that still cleared the display floors.
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
Shock absorbers (rear)
Suspension > Shock absorbers
Rear
28
×4.5
5.3%
Likely
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.
Nothing separates this year from the D-Max either side of it, so buy on the individual car. The checks below are the items that actually failed 2021 D-Max, commonest first.
What to check on a 2021 D-Max
The items that failed 2021 D-Max 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.
Shock absorbers (rear) — recorded on 15.1% of failed first attempts
Malfunction indicator lamp — recorded on 10.4% of failed first attempts
Headlamp aim — recorded on 10.2% 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.
Shock absorbers (rear) was the most common reason a 2021 D-Max failed its MOT — 15.1% of its failed first attempts. In 2025, 82.4% of 3,017 first MOTs on the 2021 Isuzu D-Max passed first time (PRS — items fixed at the station the same day — counted as a fail). The official-style rate including PRS is 87.0%. Among 532 failed first-attempt MOT tests (test year 2025), Shock absorbers (rear) appears more often than on…
Ranked by how often they were actually recorded, the items that failed 2021 Isuzu D-Maxs most often at the first attempt were Shock absorbers (rear) (15.1%), Malfunction indicator lamp (10.4%) and Headlamp aim (10.2%) — 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 common-faults table answer…
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Shock absorbers (rear) (15.1% of those tests; 80 observed failures; about 12× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Shock absorbers (rear) shows up more often than on similar cars (15.1% of those tests; 80 observed failures; about 12× 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 2021 Isuzu D-Max include Shock absorbers (rear), Malfunction indicator lamp, 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 2021 Isuzu D-Max (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.