Model Reports 4 min read Updated 18 Oct 2026

Mercedes-Benz SLK 2002: reliability & common MOT faults

In 2025, 71 in every 100 first MOTs on a 2002 Mercedes-Benz SLK were passes. Most common reason for a fail: Headlight aim.

Summary

The 2002 Mercedes-Benz SLK follows the pattern of the model years either side.

At a glance

How 1,588 first tests went in 2025.

Passed first time
71 in every 100
Did not pass first time
29 in every 100464 failed first-attempt tests
The typical car
23 yearsabout 83,343 miles
First tests counted
1,588

What failed most often

  1. Headlight aim12 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 2002 Mercedes-Benz SLK vehicles in 2025, not a prediction that any one car will have them. Faults are grouped by part of the car. A wear pattern follows age and use more than the way the car was built. They come from MOT defect codes, not manufacturer bulletins, recalls or a diagnosis of any one car.

Brakes

Two faults and one wear pattern. The strongest is the electronic stability control: 13 times as often as on similar cars.

Figures below are measured across the 464 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.

Electronic stability control

Failed on 32 first tests13 times as often as similar carsLikely evidence

What it means

An ESC warning lamp is failed only when the tester is certain it indicates an ESC malfunction, because the lamp takes various forms and the owner's handbook may need checking. The system is also called ESP, VDC or DSC, among many other names. Every failure row is Major, covering the lamp, wheel speed sensors, wiring, other components and the switch.

Brake pads (rear)

Failed on 20 first tests2.8 times as often as similar carsWear pattern

What it means

A pad worn down to its wear indicator, or contaminated with oil or grease, is Major. A pad worn below the set thickness limit, missing or incorrectly mounted is Dangerous. The manual treats an illuminated brake wear indicator as no reason for failure, although DVSA also lists an illuminated indicator as a Major row.

Also noted as an advisory

Testers also noted it as an advisory, worn but not yet failing, on 30 first tests, 2.8 times as often as on similar cars.

Anti-lock braking system (ABS)

Failed on 28 first tests2.5 times as often as similar carsPossible evidence

What it means

ABS is failed as removed only where it has obviously been removed, because not every vehicle in the age range where removal is not permitted has ABS. A warning lamp that does not light or shows an ABS fault is Major, as is a missing or excessively damaged wheel speed sensor. Every failure row for this component is Major.

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

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.

Wheel bearings (front)

Noted on 40 first tests4.6 times as often as similar carsElevated evidence

Flexible brake hoses (rear)

Noted on 50 first tests3.1 times as often as similar carsElevated evidence

Transmission oil leaks

Noted on 22 first tests2.6 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
71in 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
23in every 100
Did not pass, and were not fixed at the test station.

First-attempt pass 70.8% of 1,588 first tests (2025): only cars that passed first time count. Official-style pass 77.1%: cars fixed at the test station also count as a pass. The 6 fixed and the 23 not fixed make the 29 in every 100 that did not pass first time.

Same model, other years

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

4060801002002200520102015Older carsNewer cars
40608010020022010Newer 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, 70 in every 100 passed first time.

YearPassed first timeFirst tests
199768 in every 100551
199870 in every 100846
199971 in every 1001,157
200069 in every 1001,457
200170 in every 1001,784
2002 This car71 in every 1001,588
200367 in every 1001,449
200466 in every 1002,631
200567 in every 1004,173
200667 in every 1003,277
200767 in every 1003,223
200867 in every 1002,946
200969 in every 1002,332
201070 in every 1001,935
201175 in every 1002,396
201274 in every 1005,259
201374 in every 1004,318
201476 in every 1004,621
201580 in every 1004,657
201682 in every 1001,193

FAQs

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

The 2002 Mercedes-Benz SLK follows the pattern of the model years either side. Its main cause of failure was Headlight aim, about 12 in every 100 failed tests. In 2025, 70.8% of 1,588 first MOTs on the 2002 Mercedes-Benz SLK passed first time (PRS: items fixed at the station the same day, counted as a fail). The official-style rate including PRS is 77.1%. Among 464 failed first-attempt MOT tests (test year 2025), Electronic stability control appears more often than on similar cars (6.9% of those tests; 32 observed failures; about 13× 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 2002 Mercedes-Benz SLK at the first attempt were Headlight aim (12.1%), 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: Electronic stability control (6.9% of those tests; 32 observed failures; about 13× more often than similar cars). These are statistical signals, not a diagnosis of any individual car.
Electronic stability control shows up more often than on similar cars (6.9% of those tests; 32 observed failures; about 13× 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 2002 Mercedes-Benz SLK include Electronic stability control, Anti-lock braking system (ABS). 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 2002 Mercedes-Benz SLK (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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