Car diagnostics

Car diagnostics is the process of finding why a fault or warning light is present. The outcome is information and a recommended next step, not an automatic repair. A separate quote may follow once the cause is clear.

If you already know the job (for example worn brakes), go straight to that repair page. Use diagnostics when the cause is unclear.

Reading a stored fault code is useful, but a code does not automatically identify a part that must be replaced. Sensors, wiring, software and mechanical faults can set the same code.

Providers may need live data, road tests or further checks after the initial read. Clearing a warning light without fixing the cause usually brings the light back.

Ask what the initial fee includes: time allowance, which systems are checked, whether you receive a written summary of findings, and how further investigation is charged if the first hour is not enough.

Not every fault is identified in a single appointment. Complex intermittent problems can need more than one visit.

Plug-in code reading and some checks can be done at your address when a mobile mechanic covers the postcode and can work safely. Deeper testing, smoke tests or specialist tooling may need a workshop.

Say where the car is and whether it can be driven. See mobile mechanic or garage depending on the replies.

Fix My Vehicle UK doesn't diagnose cars. Independent providers reply to your request. Comparing quotes is free and does not book anyone in.

Once findings are clear, you can request repair quotes for the recommended work, such as brake repair or clutch replacement where relevant.