MOT advisory “Position lamp slightly affected by the operation of another lamp” — meaning and what to do

Last updated · OBDCode UK editorial

In plain English: the tester noted a lamps, reflectors or electrical equipment item that was not a fail on that MOT. Monitor to next MOT.

This advisory means the tester found position lamp that was slightly affected by the operation of another lamp — not judged bad enough to fail that recorded test, but noted for attention. It was recorded 24,609 times on UK Class 4 MOT certificates in 2025 (about #85 in this dataset).
Monitor to next MOT What to do about timing
24,609Times recorded in 2025
AdvisoryDid not fail that test

Can you drive with this?

Drive with care. This advisory alone does not normally mean you must stop driving. Still plan the repair before the next MOT so it does not become a fail.

12V electrical safety. On a 12V battery: disconnect negative first, reconnect negative last. Prevent sparks and short circuits. Stop if the battery is damaged or sits near orange high-voltage cables.

What the tester saw

MOT testers work from the DVSA inspection manual. For this item the manual wording is “A position lamp adversely affected by the operation of any other lamp”. In plain English: the tester judged that wear or deterioration on the position lamp had not gone far enough to reject at that test. That is why it was recorded as an advisory rather than a failure. It is not a statement about the vehicle’s condition or legal status today.

If it worsens to the manual fail wording above, DVSA would class that defect as Major. That grade describes the fail threshold, not the recorded advisory.

Do you need to fix it?

An advisory did not affect that test’s result. It is the tester telling you what is likely to need attention, and how soon depends on the item.

  • Monitor to next MOT. A slight position-lamp interaction can wait for the next service if the lamp still shows a steady correct light when it should. Re-check monthly; book sooner if it flickers with another circuit or goes out.
  • Can you DIY? Basic external checks may be suitable for a careful DIY driver with household tools, on firm level ground. We do not publish strip-down or fitting steps here.
  • Buying a used car? Repeated advisories for the same item across several years of MOT history mean the owner has been ignoring it. Check the car’s full record with our free MOT history check.

What happened to other cars with this advisory

Of the 6,321 cars that passed their 2024 MOT with this advisory, 3.2% (95% CI 2.8–3.7) failed on that same item the following year — 99 times the rate for cars without it.

These figures are a statistical association from the national MOT extracts. They are not a prediction about this car, and we have not inspected it.

Their rate of failing a 2025 MOT for any reason was 29.4% (95% CI 28.3–30.5), against 18.2% (95% CI 18.2–18.2) for cars that passed without this advisory.

The same 6,321 cars were 13.5 percentage points more likely not to be tested again in 2025 (20.8% (95% CI 19.8–21.8) versus 7.3% (95% CI 7.3–7.3) for cars without the advisory). The extracts do not record scrappage; a missing later test is the public signal that the vehicle was not presented.

The median car in this cohort was 17.0 years old with 95,092 miles at the 2024 test.

By age at the 2024 test

Scroll horizontally to read every age column.

AgeCarsSame-item failNot tested again
8–12 years 518 2.9% (95% CI 1.8–4.7) 9.1% (95% CI 6.9–11.9)
12–16 years 1,500 4.0% (95% CI 3.1–5.1) 16.9% (95% CI 15.1–18.9)
16 years and over 4,090 3.1% (95% CI 2.6–3.7) 24.4% (95% CI 23.2–25.8)

By mileage at the 2024 test

Scroll horizontally to read every mileage column.

MileageCarsSame-item failNot tested again
Under 40,000 miles 436 1.6% (95% CI 0.8–3.3) 11.9% (95% CI 9.2–15.3)
40,000–80,000 miles 1,854 3.6% (95% CI 2.8–4.5) 13.4% (95% CI 12.0–15.1)
80,000–120,000 miles 2,136 3.8% (95% CI 3.1–4.7) 21.3% (95% CI 19.7–23.1)
120,000 miles and over 1,895 2.7% (95% CI 2.1–3.5) 29.3% (95% CI 27.3–31.4)

Models with the highest same-item fail rate

Among models with enough cars in this cohort (at least 200 each), these had the highest rate of failing on the same item in 2025. Showing 5 qualifying models.

Scroll horizontally to read every model column.

#Make and modelCarsSame-item failNot tested again
1 Peugeot 206 425 5.4% (95% CI 3.6–8.0) 25.9% (95% CI 21.9–30.2)
2 Nissan Micra 429 5.4% (95% CI 3.6–7.9) 13.5% (95% CI 10.6–17.1)
3 Ford Transit 423 4.3% (95% CI 2.7–6.6) 20.8% (95% CI 17.2–24.9)
4 Fiat Panda 207 3.9% (95% CI 2.0–7.4) 13.5% (95% CI 9.5–18.9)
5 Renault Clio 494 3.8% (95% CI 2.5–5.9) 23.9% (95% CI 20.3–27.8)

A robustness re-run on the 3,148 cars tested in January–June 2024 only — so the next annual test almost always falls inside 2025 — found a same-item fail rate of 3.5% (95% CI 2.9–4.2) and a not-retested gap of +13.6 points. A December 2024 test may not be due until 2026, which can make a car look as if it vanished; the first-half window removes most of that censoring.

Same wording as a fail

Of the 19,059 cars that failed on this line in 2024, 2.7% (95% CI 2.5–2.9) failed on it again in 2025 — 53 times the rate for cars that did not fail on this item, and 25.9% (95% CI 25.2–26.5) of those 19,059 cars that failed were not tested again. Did this failure stay fixed?

Follow-up uses the DVSA vehicle_id, which is stable across annual releases, so the same physical car is compared from its 2024 test to its 2025 test. Browse the MOT prognosis registry. Source: DVSA Anonymised MOT tests and results, 2024 and 2025 extracts (Class 4). Contains public sector information licensed under the Open Government Licence v3.0.

Related lamps, reflectors and electrical equipment advisories

Before you agree to the work

A fault or an advisory is a quote waiting to happen. These pages set out what a garage has to tell you, what a comparable written quote should include, and what you can do if the bill is not what you agreed.

Frequency: DVSA Anonymised MOT tests and results, 2025 extract (Class 4). Wording follows the DVSA inspection manual. Contains public sector information licensed under the Open Government Licence v3.0.