Diagnose Your Car Online
Enter your vehicle, describe the problem, or upload a photo, video or engine sound. AutoFix AI helps narrow down possible causes and shows you what to check next.
How would you like to identify your vehicle?
New to this? See how online car diagnosis works.
How it works
- 1
Identify your vehicle
UK registration lookup or worldwide manual entry.
- 2
Tell us what's wrong
Symptoms, warning lights, noises or starting problems.
- 3
Add evidence
Optional OBD codes, photos, video or engine sounds.
- 4
Answer a few questions
AutoFix asks targeted follow-up questions.
- 5
Narrow down possible causes
Possible causes, safe checks and next steps.
- 6
Test and update
Use guided tests and update with real results.
More Than a Generic AI Answer
AutoFix builds its guidance around your vehicle and the evidence you provide. Instead of jumping straight to a replacement part, it asks questions, checks relevant vehicle history and helps you test possible causes before spending money.
Where they are available, it can draw on your exact make, model, year and engine, known fault patterns for that vehicle type, UK MOT history, your symptoms and follow-up answers, OBD codes, photos, video, engine sounds that can genuinely be analysed, your test results and vehicles you have saved in My Garage.
Common problems we can help with
Car won't start
No lights, a click, slow cranking or cranking that never fires.
Engine rattling or strange noises
Rattles, ticking, humming or knocking, and how to place the sound.
Check engine light
Steady or flashing, and what each one means for driving.
Car overheating
Temperature climbing or coolant disappearing — stop first, diagnose second.
Battery problems
Flat, draining or a charging fault, before you buy a battery.
Brake problems
Grinding, spongy pedal or vibration, and when to stop driving.
OBD fault codes
Read a stored code sensibly instead of ordering the part it names.
Dashboard warning lights
Red, amber and green symbols explained in plain English.
Previous MOT history can provide useful clues
For supported UK vehicles, AutoFix can review relevant previous MOT advisories and failures for recurring patterns that may relate to the current symptom. Historical MOT results are supporting evidence only and do not confirm a current fault.
For example, repeated suspension advisories plus a new knocking noise may make that area worth checking first.
Don't just guess — test it
When possible, AutoFix can walk you through simple diagnostic checks such as inspecting battery connections, checking voltage, reviewing OBD codes or looking for visible leaks. Your test results are then used to update the possible causes.
Possible cause → Help me test it → Enter result → Diagnosis updates
Safety comes first
AutoFix looks for safety-critical symptoms such as overheating, serious brake problems, oil-pressure warnings, fuel leaks and major steering faults. When appropriate, it will advise you not to drive or restart the vehicle.
New here? Read how AutoFix works, car repair help or look up a code with the OBD fault code lookup.