Diagnostics basics
What is OBD-II and EOBD?
OBD-II and EOBD are the mandatory on-board diagnostics that monitor a car's emissions and store a code when something fails. OBD-II is the United States version and EOBD the European one: they share the 16-pin port and the generic codes. In the US every light vehicle has had OBD-II since the 1996 model year; in the EU, gasoline cars since 2001 and diesels since 2004.
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What does OBD monitor?
The engine control unit continuously checks everything that affects emissions: combustion, the air-fuel mixture, the catalytic converter, the oxygen sensors, exhaust gas recirculation and, depending on the car, the fuel vapor system or the particulate filter.
When a test fails, it stores a trouble code and, if the fault affects emissions, turns on the check engine light. Any scan tool can read that through the diagnostic port.
How do OBD-II and EOBD differ?
For a driver they are the same in practice: the same connector (SAE J1962), the same reading services and the same generic codes, such as P0420 or P0300. An OBD-II reader works on a European car with EOBD.
Some legal requirements change, such as the emission limits at which the light comes on or which systems the car has to monitor. Fuel vapor leak monitoring, for example, has historically been stricter in the United States.
What can you read with OBD, and what not?
With a generic reader you see the engine's trouble codes, the data from when they were stored, live data (rpm, temperature, mixture…) and the status of the readiness monitors that inspections look at.
What is not about emissions (airbag, ABS, body, the transmission on many cars) is outside the mandatory part: each manufacturer diagnoses it with its own protocols and codes. Reading it takes a tool that talks to those control units.
Do motorcycles, trucks and vans have it too?
Light vans follow the same dates as cars in their category. Trucks and buses have their own emissions diagnostics, increasingly based on WWH-OBD and the SAE J1939 family of standards.
New motorcycles also have emissions diagnostics in the EU, but the connector and access vary by brand: check the manual.
General guidance only: every manufacturer and model has its own details. Always follow your vehicle's manual and, if in doubt, ask a workshop.
See what your car is saying
The ECO-LITE reads the engine's OBD diagnostics and also the control units that answer with each brand's protocols, over CAN, CAN FD, K-Line or DoIP.
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Frequently asked questions
Does my car have OBD?
If it is a light vehicle sold in the US from the 1996 model year, a gasoline car sold in the EU from 2001 or a diesel from 2004, yes. Many older models already had the port, but not always the full standardized diagnostics.
Does an OBD-II reader work on a European car?
Yes: EOBD uses the same connector, the same services and the same generic codes as OBD-II.
Are OBD-II and OBD2 the same?
Yes, they are two ways of writing the same standard.