Model Reports 4 min read Updated 18 Oct 2026

Citroen C5 2020: reliability & common MOT faults

In 2025, 82 in every 100 first MOTs on a 2020 Citroen C5 were passes. Most common reason for a fail: Number plate lights.

Summary

The 2020 Citroen C5 follows the pattern of the model years either side.

At a glance

How 4,889 first tests went in 2025.

Passed first time
82 in every 100
Did not pass first time
18 in every 100865 failed first-attempt tests
The typical car
5 yearsabout 36,182 miles
First tests counted
4,889

What failed most often

  1. Number plate lights15 in every 100 failed tests
  2. Tyre condition (rear)11 in every 100 failed tests
  3. Brake pads (rear)11 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 Citroen C5 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.

Lamps and electrical

Two faults. The strongest is the number plate lights (rear): 20 times as often as on similar cars.

Figures below are measured across the 864 of 865 failed first attempts (99.9%) 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.

Number plate lights (rear)

Failed on 129 first tests20 times as often as similar carsStrong 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.

Headlight (front)

Failed on 34 first tests2.3 times as often as similar carsPossible evidence

What it means

On vehicles first used on or after a set date, a halogen headlamp unit converted to take HID or LED bulbs fails for light source and lamp not compatible, which is Major. A complete unit built with those light sources is not failed for that. The precise position of the lamps is not part of the inspection beyond a visual look to see that they sit at about the same height and distance from each side.

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

Body and structure

One fault: drive shaft joints and boots (front), 5.0 times as often as on similar cars.

Drive shaft joints and boots (front)

Failed on 43 first tests5.0 times as often as similar carsLikely evidence

What it means

A constant velocity boot that is only severely deteriorated is Minor. It is Major once it is missing, split or insecure so that it no longer prevents the ingress of dirt. A transmission joint excessively worn is Major, and graded Dangerous when it is so worn it is likely to fail.

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.

Tyre tread depth (rear)

Noted on 165 first tests2.0 times as often as similar carsWear pattern

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
82in 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
14in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 82.3% of 4,889 first tests (2025): only cars that passed first time count. Official-style pass 86.4%: cars fixed at the test station also count as a pass. The 4 fixed and the 14 not fixed make the 18 in every 100 that did not pass first time.

Petrol and diesel

First testsTypical mileagePassed first time, as testedPassed first time, same mileage
Diesel2,37838,808 miles8283
Petrol2,27333,658 miles8281

Figures are in every 100 first tests. Cars with more miles usually fail more often, so the same-mileage figure gives every fuel the mileage mix of all the cars in this year.

Same model, other years

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

YearPassed first timeFirst tests
201979 in every 1006,313
2020 This car82 in every 1004,889
202186 in every 100877
202291 in every 100723

Newer cars are younger, so look for a jump rather than the climb. A year earlier (2024), when these cars were a year younger, 85 in every 100 passed first time.

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 Citroen C5.

Of 2020 Citroen C5 vehicles with under 25,000 miles, 89 in every 100 passed their 2025 MOT first time. With 51,000 miles or more, 75 in every 100 did.

Under 25,0001,026 tests
89
25,000–33,000990 tests
85
33,000–40,000 Typical car880 tests
81
40,000–51,0001,028 tests
81
51,000 and over964 tests
75

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 25,00033,000–40,00051,000 and over
Number plate lights0.23.54.4
Tyre condition (rear)3.22.41.2
Brake pads (rear)0.62.32.7
Tyre tread depth (front)1.32.32.2
Headlight aim0.90.81.8

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

When a car fails

53in every 100

of failed cars had one item to fix.

20in every 100

of failed cars had three or more items to fix.

7in 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 Citroen C5 follows the pattern of the model years either side. Its main cause of failure was Number plate lights, about 15 in every 100 failed tests. In 2025, 82.3% of 4,889 first MOTs on the 2020 Citroen C5 passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 86.4%. Among 865 failed first-attempt MOT tests (test year 2025), Number plate lights (rear) appears more often than on similar cars (14.9% of those tests; 129 observed failures; about 20× 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 Citroen C5 at the first attempt were Number plate lights (14.9%), Tyre condition (rear) (11.5%) and Brake pads (rear) (11.3%), 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: Number plate lights (rear) (14.9% of those tests; 129 observed failures; about 20× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Number plate lights (rear) shows up more often than on similar cars (14.9% of those tests; 129 observed failures; about 20× 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 Citroen C5 include Number plate lights (rear), Drive shaft joints and boots (front), Headlight (front). 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 Citroen C5 (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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