Model Reports 4 min read Updated 18 Oct 2026

Fiat Doblo 2020: reliability & common MOT faults

In 2025, 69 in every 100 first MOTs on a 2020 Fiat Doblo were passes. Most common reason for a fail: Diesel engine warning light.

Summary

The 2020 Fiat Doblo follows the pattern of the model years either side.

At a glance

How 1,153 first tests went in 2025.

Passed first time
69 in every 100
Did not pass first time
31 in every 100357 failed first-attempt tests
The typical car
5 yearsabout 48,848 miles
First tests counted
1,153

What failed most often

  1. Diesel engine warning light20 in every 100 failed tests
  2. Coil spring (front)16 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 Fiat Doblo 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.

Brakes

One fault: brake pedal, 29 times as often as on similar cars.

Figures below are measured across the 355 of 357 failed first attempts (99.4%) that recorded an odometer reading in 2025. Mileage is needed to compare like with like.

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.

Brake pedal

Failed on 26 first tests29 times as often as similar carsPossible evidence

What it means

A brake pedal rubber worn smooth is not a defect, and nor is a worn design pattern on an aftermarket rubber. A pedal with no rubber is rejected if its grooves or raised grip sections are worn smooth, unless the vehicle was made without them. Insufficient reserve travel is Major, but a vehicle is failed for it only if the pedal or lever is touching the floor or handlebar.

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

Suspension

One fault: coil spring (front), 13 times as often as on similar cars.

Coil spring (front)

Failed on 57 first tests13 times as often as similar carsLikely evidence

What it means

A missing bump stop rubber is not a reason to fail a coil spring. When the vehicle is jacked and lowered, a spring that does not correctly locate as the suspension returns to its normal running position is rejected as insecurely attached. A missing spring is Major, and graded Dangerous where directional control is affected.

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

Noise, emissions and leaks

Two faults. The strongest is the diesel engine warning light: 6.4 times as often as on similar cars.

Diesel engine warning light

Failed on 70 first tests6.4 times as often as similar carsLikely 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.

Petrol engine warning light

Failed on 27 first tests3.0 times as often as similar carsPossible evidence

What it means

The malfunction indicator lamp (MIL) on a petrol engine is a Major failure when it is illuminated indicating a malfunction. The detail line DVSA gives for the same row also names an inoperative lamp. The test covers only certain petrol vehicles, depending on their age, size and fuel type.

Data: UK MOT open data, 2025. 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
69in every 100
Passed on the first test.
Fixed at the station
6in every 100
Failed, then fixed at the test station the same day.
Failed
25in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 69.0% of 1,153 first tests (2025): only cars that passed first time count. Official-style pass 74.8%: cars fixed at the test station also count as a pass. The 6 fixed and the 25 not fixed make the 31 in every 100 that did not pass first time.

Same model, other years

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

4060801002005201020152020Older cars
40608010020102020Older 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, 75 in every 100 passed first time.

YearPassed first timeFirst tests
200350 in every 100305
200447 in every 100590
200549 in every 100832
200651 in every 1001,312
200752 in every 1001,803
200856 in every 1001,678
200960 in every 1001,375
201057 in every 1001,562
201154 in every 1001,661
201257 in every 1001,820
201371 in every 1005,795
201459 in every 1005,136
201562 in every 1004,378
201663 in every 1003,195
201765 in every 1002,323
201870 in every 1001,871
201970 in every 1001,602
2020 This car69 in every 1001,153
202174 in every 1001,810
202276 in every 100666

FAQs

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

The 2020 Fiat Doblo follows the pattern of the model years either side. Its main cause of failure was Diesel engine warning light, about 20 in every 100 failed tests. In 2025, 69.0% of 1,153 first MOTs on the 2020 Fiat Doblo passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 74.8%. Among 357 failed first-attempt MOT tests (test year 2025), Brake pedal appears more often than on similar cars (7.3% of those tests; 26 observed failures; about 29× 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 Fiat Doblo at the first attempt were Diesel engine warning light (19.7%) and Coil spring (front) (16.1%), 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: Brake pedal (7.3% of those tests; 26 observed failures; about 29× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Brake pedal shows up more often than on similar cars (7.3% of those tests; 26 observed failures; about 29× 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 Fiat Doblo include Brake pedal, Coil spring (front), Diesel engine warning 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.
This page highlights MOT failure patterns for the 2020 Fiat Doblo (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.

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