Six quick dashboard checks before buying a used car in the UK: the bulb test, a cold start, MOT history, fault codes and recalls.
Looking for more detail? Our full guide covers this topic in depth, with step-by-step advice and sources.
Dashboard lights are one of the quickest clues to a used car's condition. A few checks before you buy can save a lot of money.
1. Check the bulb test
Turn the ignition on without starting the engine. Most warning lights, including engine, ABS, airbag and oil, should light up briefly. If one does not, the bulb may have been removed or the cluster tampered with to hide a fault.
2. Start from cold
Ask for the engine to be cold when you arrive. Watch all the lights go out after starting. Some faults only show when cold.
3. Test drive long enough
Drive for at least 20 minutes, including faster roads if you can. Some faults, such as DPF or gearbox problems, only appear once things warm up.
4. Look at the MOT history
The free GOV.UK MOT history service shows past failures and advisories, such as an ABS or airbag light. Repeated advisories for the same thing are a warning sign.
5. Ask for a code scan
A garage or a mobile inspector can scan for stored fault codes. Recently cleared codes, shown by incomplete readiness monitors, can mean a seller has hidden a problem.
6. Check recalls
Use the GOV.UK recall checker to see whether any safety recalls are outstanding.
If a light is on
Do not accept "it's just a sensor". Ask for a written diagnosis, a price reduction to cover the repair, or walk away. Buying from a dealer gives you more rights under the Consumer Rights Act 2015 than a private sale.
Sources and further reading
- GOV.UK: MOT inspection manual for cars
- GOV.UK: MOT changes from 20 May 2018
- The Highway Code
- GOV.UK: check MOT history
- GOV.UK: check for vehicle recalls
Facts checked on 20 October 2026. Spotted an error? Tell us and we will correct it.