Car diagnostic app

The car diagnostic app that doesn't need a plug.

Describe the symptom or enter a trouble code. Add your vehicle details, work through suggested checks and record what you find. Save the session and resume when you have the next test result.

MECH AI works in English, Spanish, Portuguese, Russian, German, French, and Italian — the AI answers in your language.

Start a guided diagnosis See the diagnostic demo

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Account required · daily free allowance · no card to start

Watch a guided car diagnosis in action — no scanner — watch on its own page

What is a car diagnostic app?

A car diagnostic app helps explain symptoms and trouble codes and organize checks. MECH AI uses the vehicle details and test results you provide to suggest next steps. It cannot inspect the car or confirm a failed part from a code alone. Verify suggestions against applicable service information. A compatible adapter is needed to read codes directly from the vehicle.

One app, six diagnostic tools

Everything between "what's that light" and "fixed."

OBD2 code decoder

Look up a P, B, C, or U trouble code and review possible causes. Manufacturer-specific meanings and reference coverage vary; a code alone does not identify a failed part.

Symptom diagnosis

No code? Describe what the car is doing — "shakes at 70", "grinding when braking" — and the AI Mechanic narrows it down question by question.

Guided diagnostics

Structured diagnostic sessions you can pause and resume. Start in the driveway, finish after work — it remembers where you left off.

Vehicle Health score

Review the available vehicle information and recorded observations. A score is not a physical inspection or a prediction that a component will fail.

TSBs & recalls

Search service bulletins and recall information. Check the model year, engine, market and applicable VIN range before relying on a match.

Repair guides & parts

Review repair steps, suggested tools and parts listings. Verify procedures and part fitment against the vehicle and applicable service information.

Want the deep dive on a specific code first? Browse the free OBD2 diagnostic code library or the symptom guides — no account needed.

What about OBD2 scanners?

Hardware reads codes. Diagnosis is the hard part.

A code such as P0420 is a starting point for testing, not a parts order. Bring the code from your scanner into a guided session, or pair a compatible Bluetooth LE (BLE) or WiFi ELM327 adapter with the iOS or Android app to read codes and supported sensor data. Available functions vary by vehicle and adapter. The web app does not connect directly to an OBD2 adapter.

Comparing options? See the honest head-to-heads: MECH AI vs FIXD, vs OBD AI, vs Carly — or the full comparison hub.

FAQ

Car diagnostic app questions.

Do I need an OBD2 scanner to use a car diagnostic app?

Not with MECH AI. It works from your words — describe the symptom, type in a code you saw on a loaner scanner, or show it a photo of the dashboard. If you already own a reader, the built-in decoder interprets what it found. And if it's a Bluetooth LE (BLE) or WiFi ELM327 adapter, the iOS and Android app pairs with it directly to read your codes and live sensor data (read-only).

Is the app free?

Create an account for the free daily allowances, including guided diagnosis and a daily AI Mechanic chat allowance — no card required. Public code guides need no account. Paid plans add tools and higher allowances; check the pricing page for current limits.

Does it work on iPhone and Android?

Both — iOS 16+ and Android 7+ — plus a full web app, so you can use it on a laptop or shop tablet with the same account. Your garage, history, and subscription sync across all of them.

What trouble codes can it diagnose?

You can ask about powertrain (P), body (B), chassis (C) and network (U) codes. Coverage varies, especially for manufacturer-specific definitions. The public code library offers guides for common codes; confirm the meaning for your vehicle before testing or replacing parts.

How is this different from FIXD or other scanner apps?

Compare the task you need: reading codes requires compatible hardware, while a guided session works with symptoms, codes and test results you provide. MECH AI combines guided sessions with repair-reference tools; coverage and plan limits apply. See the comparison hub for product-specific details.

Start with the symptom. Record what you find.

Create an account and start a guided session with the daily free allowance. No card to start.

Start a guided diagnosis

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100K+ downloads · iOS · Android · Web