What is an OBD2 port and where is it located?

The OBD-II (On-Board Diagnostics) port is a standardized connection point in your vehicle for reading diagnostic data. In most cars, it's located under the dashboard on the driver's side, near the steering column. All petrol and diesel cars sold in the US since 1996 have this port.

Do I need any special hardware?

You need an ELM327-compatible adapter (USB, Bluetooth, or Wi-Fi). These cost between $10–$30 and are widely available online. AIscanAuto works with any standard ELM327 adapter.

Is AIscanAuto really free?

Yes, the core features — DTC scanning, live data, and up to 10 AI analyses per month — are completely free. The Pro subscription unlocks unlimited AI analyses, advanced graphs, and freeze frame history.

What platforms are supported?

AIscanAuto runs on Windows 10+, macOS 12+, and Ubuntu 20.04+. Download the appropriate installer from our download page.

Can AIscanAuto clear my check engine light?

Yes, the app can read and clear DTC codes, which will turn off the check engine light. However, if the underlying issue persists, the light will return.

Is my data kept private?

Absolutely. All diagnostic data stays on your device. Our local AI mode works entirely offline — no data is sent to any server.

How does the AI assistant work?

Our AI analyzes your vehicle's diagnostic data and provides plain-language explanations of fault codes, suggests likely causes, and recommends next steps for repair. The Pro plan includes unlimited AI queries.

Can I use AIscanAuto on multiple devices?

Yes, you can install AIscanAuto on any number of devices. Your Pro subscription syncs across devices when you sign in with the same account.

P1191 Dongfeng: Upstream Air-Fuel Probe Polarity Swap

P1191 on Dongfeng indicates reversed polarity wiring of the front oxygen sensor before the catalyst. This prevents correct voltage signals to the ECM, causing fuel trim errors and drivability problems.