Reading a fault code yourself with a USB adapter
An optional power-user path: read a code directly in your browser with a cheap ELM327 adapter.
What this is for
If you already own a cheap USB (or paired-over-Bluetooth) ELM327-style OBD-II adapter, you can read your fault code directly in your browser - no app to install - and it feeds straight into the same diagnosis intake form.
Browser support - please read before buying anything
This uses a real web standard called Web Serial, which only exists in Chrome, Edge, or Opera on desktop. It does not work on:
- Any mobile browser, including Chrome on Android - Web Serial isn't available on mobile at all.
- Safari or Firefox, on any device - neither browser supports Web Serial.
This is a real platform limitation, not a bug on our end. If your browser doesn't support it, the page tells you clearly rather than silently failing - just enter your fault code manually instead, which works exactly the same for your report.
What it reads
A one-time read of your stored diagnostic trouble codes (DTCs) using the standard OBD-II Mode 03 request. Workshops get a deeper version of this with live, continuously-updating sensor graphs - see Using the Live Data Monitor and OBD Tools.