Model Reports 4 min read Updated 18 Oct 2026

Isuzu D-Max 2020: reliability & common MOT faults

In 2025, 77 in every 100 first MOTs on a 2020 Isuzu D-Max were passes. Most common reason for a fail: Shock absorbers (rear).

Summary

The 2020 Isuzu D-Max follows the pattern of the model years either side.

At a glance

How 2,455 first tests went in 2025.

Passed first time
77 in every 100
Did not pass first time
23 in every 100575 failed first-attempt tests
The typical car
5 yearsabout 53,305 miles
First tests counted
2,455

What failed most often

  1. Shock absorbers (rear)22 in every 100 failed tests
  2. Anti-roll bar pins and bushes (front)10 in every 100 failed tests
  3. Diesel engine warning light9 in every 100 failed tests

How we count this. Data: UK MOT open data, 2025. Only Class 4 cars on their first MOT of the year are counted. A car that fails and is fixed at the test station still counts as a fail in the first-attempt rate. These are raw results, not adjusted for age, mileage, or peer mix. The MOT does not test engine or gearbox internals.

Note:

These are patterns across 2020 Isuzu D-Max vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Suspension

Two faults. The strongest is the wheel bearings (front): 21 times as often as on similar cars.

Figures below are measured across the 575 failed first attempts in 2025 that had a mileage recorded, which allows a like-for-like comparison.

We only list faults with at least 20 failures and a rate of about 2.0 times that of similar cars, which keeps one-off results out of the list.

Wheel bearings (front)

Failed on 44 first tests21 times as often as similar carsLikely evidence

What it means

Excessive play in a wheel bearing, or a bearing that is excessively rough, is Major. Play so excessive that the bearing is likely to break up or directional control is impaired is Dangerous, and so is a bearing so rough that it is likely to overheat or break up.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 104 first tests, 124 times as often as on similar cars.

Shock absorbers (rear)

Failed on 126 first tests16 times as often as similar carsStrong evidence

What it means

Slight seepage that leaves a film of fluid on a shock absorber does not fail it. Severe leakage, or damage so that it does not function, is Major. A shock absorber missing or likely to become detached is graded Dangerous, though a missing one is only rejected if shock absorbers were fitted as standard.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 55 first tests, 8.0 times as often as on similar cars.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage. Advisories count notes recorded on failed first tests only.

Lamps and electrical

Three faults. The strongest is the rear fog light: 9.7 times as often as on similar cars.

Rear fog light

Failed on 41 first tests9.7 times as often as similar carsLikely evidence

What it means

A missing obligatory rear fog lamp, one that is not working, or one that does not emit a steady red light is graded Major. A rear fog lamp adversely affected by the operation of any other lamp is Major too. The manual allows it to go out when main beam is switched on or when dipped beam headlamps are switched off.

Individual sidelight or tail light (rear)

Failed on 26 first tests4.5 times as often as similar carsPossible evidence

What it means

A position lamp showing red light to the front or white light to the rear is Major. Rear lamps must show a steady red light, and front ones can show white, predominantly white with a blue tinge, or yellow if combined in a yellow headlamp. With a multiple light source, up to half not working is Minor and more than half is Major.

Number plate lights

Failed on 28 first tests2.3 times as often as similar carsPossible evidence

What it means

Registration plate lamps must light up the rear registration plate and operate at the same time as the position lamps. A missing or inoperative lamp is Major when the plate has only one lamp or all its lamps are not working, and Minor when the plate has several lamps or light sources and not all have failed. A lamp throwing direct white light to the rear is also Minor.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Brakes

One fault: handbrake efficiency below minimum (roller test), 2.5 times as often as on similar cars.

Handbrake efficiency below minimum (roller test)

Failed on 21 first tests2.5 times as often as similar carsPossible evidence

What it means

A parking brake with efficiency below the minimum requirement is Major, and graded Dangerous where efficiency is less than half of the required value. On a roller brake tester, the requirement counts as met if more than half of the wheels of a brake system lock. The check applies only to vehicles whose parking brake was not already tested as the secondary brake.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Noise, emissions and leaks

One fault: diesel engine warning light, 2.4 times as often as on similar cars.

Diesel engine warning light

Failed on 50 first tests2.4 times as often as similar carsPossible evidence

What it means

An engine malfunction indicator lamp that is illuminated to show a malfunction is graded Major on a diesel, but only on the diesels the test covers, which depends on the vehicle type and when it was first used. DVSA lists it under exhaust emissions for compression ignition engines, and the detail line for the row also names an inoperative lamp.

Data: UK MOT open data, 2025. Compared with cars of the same age and mileage.

Advisories

Other things testers noted as worn or close to failing, more often than on similar cars.

An advisory is a note from the tester about something that has not failed yet. It is an early warning, not a fail. Advisories for the faults above are shown with those faults.

Anti-roll bar pins and bushes (front)

Noted on 53 first tests95 times as often as similar carsLikely evidence

Rigid brake pipes (rear)

Noted on 22 first tests23 times as often as similar carsElevated evidence

Suspension arm ball joint (front)

Noted on 23 first tests4.0 times as often as similar carsElevated evidence

Data: UK MOT open data, 2025. Counts cover advisories recorded on failed first tests only, compared with cars of the same age and mileage.

MOT pass rates

How first tests ended, and how the pass rates are counted.

Passed first time
77in every 100
Passed on the first test.
Fixed at the station
4in every 100
Failed, then fixed at the test station the same day.
Failed
19in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 76.6% of 2,455 first tests (2025): only cars that passed first time count. Official-style pass 81.1%: cars fixed at the test station also count as a pass. The 4 fixed and the 19 not fixed make the 23 in every 100 that did not pass first time.

Same model, other years

Passed first time in every 100, all tested in 2025.

40608010020152020Older carsNewer cars
4060801002020Older cars

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 79 in every 100 passed first time.

YearPassed first timeFirst tests
201258 in every 1001,084
201360 in every 1002,464
201462 in every 1003,576
201565 in every 1004,249
201666 in every 1004,027
201770 in every 1004,085
201872 in every 1003,705
201975 in every 1003,690
2020 This car77 in every 1002,455
202182 in every 1003,017
202284 in every 1003,378

If you are buying one

What this year's MOT record means for the decision in front of you.

Mileage matters most on a 2020 D-Max.

Of 2020 D-Max vehicles with under 33,000 miles, 84 in every 100 passed their 2025 MOT first time. With 81,000 miles or more, 67 in every 100 did.

Under 33,000486 tests
84
33,000–47,000509 tests
81
47,000–61,000 Typical car483 tests
76
61,000–81,000474 tests
75
81,000 and over502 tests
67

What to check at your mileage

How often each fault turned up on a failed first test, by the car's mileage. Read it as: what is likely to need looking at on a car like the one in front of you.

Under 33,00047,000–61,00081,000 and over
Shock absorbers (rear)2.36.46.2
Anti-roll bar pins and bushes (front)0.82.34.0
Diesel engine warning light3.51.42.6

Faults per 100 first tests, by the car's mileage at the test.

When a car fails

32in every 100

of failed cars had one item to fix.

44in every 100

of failed cars had three or more items to fix.

5in every 100

of all first tests had a defect the tester marked dangerous (unsafe to drive away).

Every figure here is a first-attempt MOT rate from DVSA open data for this model line, for cars of this model year tested in 2025. Each mileage band holds a fifth of the tests. 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.

The 2020 Isuzu D-Max follows the pattern of the model years either side. Its main cause of failure was Shock absorbers (rear), about 22 in every 100 failed tests. In 2025, 76.6% of 2,455 first MOTs on the 2020 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 81.1%. Among 575 failed first-attempt MOT tests (test year 2025), Shock absorbers (rear) appears more often than on similar cars (21.9% of those tests; 126 observed failures; about 16× more often than similar cars). There is no single reliability score here; this is a pre-purchase checklist built from DVSA open data, not a guarantee for any individual car.
Ranked by how often they were actually recorded, the items that most often failed a 2020 Isuzu D-Max at the first attempt were Shock absorbers (rear) (21.9%), Anti-roll bar pins and bushes (front) (9.6%) and Diesel engine warning light (8.7%), each as a share of the year's failed first attempts. That is what goes wrong most often on the car. The common faults table shows a different measure: faults that are unusual compared with similar cars.
Among failed first-attempt tests we highlight patterns that appear more often than on similar cars. Top example: Shock absorbers (rear) (21.9% of those tests; 126 observed failures; about 16× 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 (21.9% of those tests; 126 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 checkpoint, not a manufacturer service bulletin.
Common MOT problem areas for the 2020 Isuzu D-Max include Shock absorbers (rear), Wheel bearings (front), Rear fog light. These are the faults that stand out compared with similar cars, not a complete list of what can go wrong on any 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 2020 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.

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.
  • If the data for a car is too thin to say anything useful, we say so rather than guess.

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

Check any vehicle’s MOT history

Full MOT history, mileage records, and reliability insights for any UK vehicle.

Run a free check