How to connect an OBD-II adapter and take the first readings
From the socket under the wheel to the first list of fault codes — eight steps, about ten minutes.
Find the socket
The OBD-II socket is inside the cabin, most often under the steering column on the left, sometimes behind a cover near the passenger's feet. It is trapezoidal, with sixteen pins. Cars from about 2001 always have one.
Turn the ignition off and plug the adapter in
Plug it in with the engine off — that habit avoids a voltage spike. The adapter should go all the way in and sit tight.
Turn the ignition on
The «ignition on» position is enough, the engine may stay off. A light on the adapter means it has power.
Pair the adapter with the phone
A Bluetooth adapter is paired in the phone settings first (the usual code is 1234 or 0000). BLE and Wi-Fi need no pairing: the app finds BLE itself, and a Wi-Fi adapter is joined like a hotspot.
Pick the adapter in CarScan
Open «Devices» and pick yours. The app checks what the adapter is and what it can do — and says plainly if it is a fake that reads codes but cannot talk to the control units directly.
Run the scan
Press «Check». The app goes through the control units and shows which answered and which stayed silent. Silence is not «all good», and we say so.
Read the explanations
Every code found is explained in words: what it means, what usually stands behind it and where it is cheaper to start. The same explanations live in the site directory and can be read beforehand.
Save the report
The report for the mechanic is plain text: forward it in a chat or print it. The conversation at the workshop gets shorter with it.