What OBD2 is and since when your car has it
OBD stands for on-board diagnostics: the car keeps an eye on itself and reports what it sees through a standard socket. The basics, straight to the point.
What it’s for
OBD was born out of emissions. The law requires the car to monitor everything that can make the exhaust dirtier (ignition, mixture, catalytic converter, oxygen sensors, EGR, fuel tank vapours) and to turn on the check engine light when something fails. And it requires that anyone can read it with a standard tool through a standard socket, without depending on the dealer.
Through that socket you can read fault codes, live engine data (revs, temperatures, oxygen sensors, load), the VIN and the status of the emissions checks. It’s what garages, the ITV and apps like Final OBD use.
OBD2, OBD-II and EOBD: almost the same thing
OBD-II, or OBD2, is the United States version, mandatory there on all cars and light vans from the 1996 model year. EOBD is the European version, approved in 1998 with Directive 98/69/EC, and in practice it’s the same: the same socket, the same fault codes and the same data. An OBD2 scanner reads an EOBD car with no difference at all.
Which year your car got it
- Petrol: mandatory on new cars registered in the European Union from 1 January 2001 (new models from 2000).
- Diesel: from 1 January 2004 (new models from 2003).
- Vans and heavier passenger vehicles: a little later depending on their weight, up to 2007 for the heaviest diesels.
Many earlier cars already had the socket, especially petrol cars from the late nineties, though not always with full OBD. If your car is from those dates onwards, it definitely has it. In Spain, the ITV also reads Euro 5 and Euro 6 cars and vans through that socket.
What standard OBD doesn’t cover
Standard OBD mostly covers the engine and whatever affects emissions. The ABS, airbag, gearbox, body or climate control have their own control units, each manufacturer talks to them in its own way, and they aren’t required to report anything through standard OBD. Reaching them is what sets an app that knows your make apart from one that only reads the engine. In Final OBD, the standard part is in Free and the in-depth check of every control unit is in Pro.
Carry on from here
More guides
OBD2 adapters: clones, good ones and which to buy
ELM327 clones versus vLinker, OBDLink and co.; classic Bluetooth, BLE or wifi; iPhone and what to buy.
How to read and clear your car’s fault codes
Step by step, what each code means and when it makes sense to clear.
The check engine light: steady, flashing and what to do
Steady or flashing, whether you can keep going and why it sometimes goes off by itself.
The Spanish ITV and the OBD socket: what they read
What the Spanish test centre reads through the OBD socket, what counts as major and how to avoid surprises.
The OBD2 readiness monitors
What each monitor checks, why they show not ready and how they complete.
What OBD2 is and since when your car has it
What it’s for, the difference between OBD2 and EOBD, and the year it became mandatory.
The OBD2 connector: where it is and what each pin carries
Where to look for it and what each of its 16 pins is for.
The OBD2 protocols: how your car talks
CAN, K-line (ISO 9141-2 and KWP2000) and J1850: which car uses which.
The OBD2 modes, one by one
Live data, fault codes, clearing, pending, VIN and permanent: what each mode asks for.
OBD2 live data and its normal values
Rpm, temperatures, fuel trims, oxygen sensors, load and boost: what each PID is and which value is normal.
Coming soon
Mid to late October 2026
If you want to try it in your car before anyone else, send us your email and we will add you as a tester.
info@finalobd.com