Pre-MOT checklist: 15 minutes that prevent most failures

Updated 23 July 2026 · OBDCode UK editorial

Most MOT failures are preventable at home: lamps, tyres, suspension knocks, wipers/washers and dashboard warning lights top the national failure tables year after year. This 15-minute walk-round catches them before the tester does.

Lights (5 minutes — the #1 electrical failure group)

  • Walk the car with everything on: side, dip, main beam, indicators, hazards, fogs, reverse, brake lights (use a wall reflection or a helper), number-plate bulbs.
  • Check lenses aren’t cracked or heavily misted; insecure headlamps fail.

Tyres (3 minutes — 2,786,889 defects recorded last year)

  • Tread: 1.6mm legal minimum across the central three-quarters. The 20p test: rim hidden = OK.
  • Condition: cuts, bulges, cracking sidewalls, and perishing — the single most recorded advisory in the country.
  • Match: same size on the same axle; no crossed radial types.

Warning lamps (2 minutes — an instant Major defect)

Ignition on: every lamp should light, then go out after start. Any that stay on — engine, ABS, airbag, EPS, tyre pressure — is a fail. An OBD2 scanner reads and (after fixing) clears the engine-side faults; see the code library for what yours means. TPMS lamps often just need pressures set and a reset.

Wipers, washers, screen (2 minutes)

  • Wipers must clear the screen without smearing streaks in the driver’s sweep; splits fail.
  • Washers must reach the screen — check the jets and top up.
  • Chips: larger than 10mm in the driver’s zone A, or 40mm anywhere swept, is a fail.

Quick extras that catch real failures

  • Horn works; seatbelts latch and retract on every seat.
  • Suspension: bounce each corner — continued bouncing or clonks over speed bumps point at the national #1 failure system. See what fails on your model.
  • Brakes: firm pedal, no pull to one side, handbrake holds on a slope.
  • Under the car: obvious fluid drips and a blowing exhaust are testable items.
  • Reg plates: legible, correct spacing, both present.

Then run your plate through the MOT history check and re-read last year’s advisories — they are the tester’s written prediction of this year’s fail items.

General guidance for UK drivers, not professional advice. MOT rules follow the DVSA inspection manual (2026 edition).