What does 4.11 mean on an MOT certificate?

It refers to sub-section 4.11 of the MOT inspection manual, "Electrical wiring", within section 4, lamps, reflectors and electrical equipment. The letter or letters after it — (a), (b)(i) and so on — identify the specific defect from the 9 listed here. 3 of them are graded Dangerous, 3 Major and 3 Minor.

Does a Minor defect fail the MOT?

No. a defect with no significant effect on safety or the environment. Recorded on the certificate; the vehicle passes. Major and Dangerous defects fail. A Dangerous defect also means the car must not be driven until it is repaired.

Section 4 · Lamps, reflectors and electrical equipment

4.11 Electrical wiring

Manual indexed 3 September 2026

Quick answer

Sub-section 4.11 of the MOT inspection manual covers electrical wiring and lists 9 defects, 3 of them Dangerous. A reference like "(4.11 (a)(i))" on a certificate points to the matching row below. The most recorded is "Electrical wiring likely to touch hot or rotating parts, drag on the ground or the connectors for braking or steering disconnected", about 0.0 times per 100 failed tests.

Official wording

The defect clauses

4.11 (a)(i)Minor
Electrical wiring insecure or inadequately secured
4.11 (a)(ii)Major
Electrical wiring insecure and in contact with sharp edges or connectors likely to become disconnected
Body has a sharp edge likely to cause injury explained: what it means and what puts it right
4.11 (a)(iii)Dangerousunder 0.1 per 100 fails
Electrical wiring likely to touch hot or rotating parts, drag on the ground or the connectors for braking or steering disconnected
4.11 (b)(i)Minor
Electrical wiring slightly deteriorated
4.11 (b)(ii)Major
Electrical wiring so damaged or deteriorated it is likely to cause a short-circuit
4.11 (b)(iii)Dangerous
Electrical wiring for braking or steering components extremely deteriorated
4.11 (c)(i)Minor
Electrical wiring insulation damaged or deteriorated
4.11 (c)(ii)Major
Electrical wiring insulation heavily deteriorated
4.11 (c)(iii)Dangerous
Electrical wiring insulation in such a condition there is an imminent risk of fire or formation of sparks

Wording and categories reproduced from the DVSA inspection manual under the Open Government Licence. Frequencies are items per 100 failed class 4 tests across the DVSA anonymised MOT dataset; a clause with no figure was not recorded often enough to appear in any model’s top forty failure items. 1 of 9 clauses link to our own explanation.

Grading

What the categories mean

Dangerous: a direct and immediate risk to road safety or the environment. The vehicle fails and must not be driven until repaired, even to a garage.
Major: a defect that affects safety, the environment or other road users. The vehicle fails.
Minor: a defect with no significant effect on safety or the environment. Recorded on the certificate; the vehicle passes.

The full guide to defect grading

Section 4

Other sub-sections of lamps, reflectors and electrical equipment

All sections of the manual

Common questions

What does 4.11 mean on an MOT certificate?: It refers to sub-section 4.11 of the MOT inspection manual, "Electrical wiring", within section 4, lamps, reflectors and electrical equipment. The letter or letters after it — (a), (b)(i) and so on — identify the specific defect from the 9 listed here. 3 of them are graded Dangerous, 3 Major and 3 Minor.
Which electrical wiring defect is recorded most often?: "Electrical wiring likely to touch hot or rotating parts, drag on the ground or the connectors for braking or steering disconnected" (4.11 (a)(iii)), recorded about 0.0 times per 100 failed MOT tests nationally.
Does a Minor defect fail the MOT?: No. a defect with no significant effect on safety or the environment. Recorded on the certificate; the vehicle passes. Major and Dangerous defects fail. A Dangerous defect also means the car must not be driven until it is repaired.