Pistonly is your pocket diagnostic engineer: it reads your car's fault codes, cross‑checks your service history, and tells you the likely cause and what to check next. Need help? Email [email protected] and we'll get back to you.

Quick start

1. Add your car — by VIN (Pistonly fills in make, model, generation and engine) or by hand.
2. Add fault codes — read them live from an OBD‑II adapter, or type in codes you already have (from a shop, PIWIS, ISTA or VCDS). No adapter needed to type them in.
3. Diagnose — tap Run. Pistonly's AI gives you a verdict, ranked likely causes and a step‑by‑step checklist.
4. Keep a service book — record what you've done so the AI can tell whether past work helps or hurts the current problem.

No car or adapter handy? On the first screen choose "Take the demo for a spin" to explore with a simulated car, or "Type in fault codes" to try the AI diagnostician right away.

FAQ

Do I need an OBD‑II adapter? Not for the AI diagnostician — you can type in codes by hand. You need an ELM327‑compatible Bluetooth adapter only for live data (real‑time sensors, control units, service functions, odometer cross‑check).

Which adapters work? Any Bluetooth adapter compatible with the ELM327 command set.

How does the free AI work? You get 3 full AI diagnoses every month for free — no purchase and no API key required. They run on our server.

What is Pistonly Pro? An auto‑renewable subscription (monthly or annual) that unlocks unlimited AI diagnoses plus the pro tools: Control units, Service functions, Odometer cross‑check, Enhanced PIDs and CSV data logging.

Can I get unlimited AI without subscribing? Yes. In Settings → AI analysis add your own Claude (Anthropic) or Perplexity API key, and AI runs on your own account with no subscription.

How do I restore or cancel a subscription? Restore: on the paywall tap Restore. Cancel: iOS Settings → your name → Subscriptions → Pistonly. Subscriptions renew until cancelled.

Is my data private? Yes. There's no account; your garage, history and VIN stay on your device, and your VIN is never sent to our servers. See the Privacy Policy for details.

Is the diagnosis a guarantee? No. Pistonly is advisory — strong hypotheses and a checklist to work through. It doesn't replace a professional inspection.

Contact

[email protected]