Guides
OBD2 guides
Short, practical guides for using an OBD2 adapter and your phone. Every guide lists its sources.
How to choose an ELM327 adapter
What an ELM327 adapter is, how to match it to your car and phone, Bluetooth vs BLE vs Wi-Fi vs USB, and why cheap clones may only read the engine.
OBD2 check before buying a used car
How to scan a used car with an OBD2 adapter before you buy: trouble codes, pending codes, readiness monitors and what a recent code clear can hide.
Check engine light on: what to do
Steady or blinking check engine light? What it means, when to stop driving, the gas cap check, how to read the code and what to do after the repair.
See also: OBD2 by car brand · OBD2 trouble code guides
Read your car with OBD Master Pro
Use your Android phone with a generic ELM327 adapter over Bluetooth, Bluetooth LE, Wi-Fi or USB to read codes, live data and emissions readiness.