Volkswagen OBD2 guide

Which Volkswagen models have OBD2?

In the United States, OBD II has been required on all 1996 and newer gasoline passenger cars and light trucks, and on 1997 and newer diesel passenger cars and light trucks. A small number of 1994 and 1995 gasoline models already had it. On US models you can confirm it by looking for "OBD II" on the emission control label under the hood.

In the European Union the equivalent system is called EOBD. For petrol passenger cars (up to 2,500 kg) it applied to new type approvals from 1 January 2000 and to all newly registered cars from 1 January 2001. For diesel passenger cars (up to six seats and 2,500 kg) the dates were 1 January 2003 for new types and 1 January 2004 for all new registrations. Heavier passenger cars and vans followed on later dates.

These dates are the legal minimum for new vehicles in each market. Some cars had OBD earlier, and imported or grey market cars follow the rules of the market they were built for, so the exact start year may vary by model.

Where is the OBD2 port on a Volkswagen?

The OBD2 connector (officially the Data Link Connector, or DLC) is generally under the dashboard on the driver's side, near the steering column. EPA guidance treats the area under the driver's side of the instrument panel as the preferred location and allows a few other locations, so on some models it sits behind a small cover, a panel or in the center console.

For 1996 to 2000 US models, the EPA's connector location chart lists where the connector is on each Volkswagen model, including the ones where it is behind a cover.

If you can't find it, check your owner's manual, which generally shows the connector or the panel that covers it.

Which OBD2 protocol does it use?

OBD2 allows five communication protocols: SAE J1850 PWM, SAE J1850 VPW, ISO 9141-2, ISO 14230-4 (KWP2000) and ISO 15765-4 (CAN). From the 2008 model year, cars sold in the US must use CAN. Earlier cars may use any of the five, and which one depends on the model and year.

We don't list protocols per Volkswagen model here because we could not confirm them from two independent sources. You don't need to know it in advance: an ELM327 class adapter and the app detect the protocol automatically.

What generic OBD2 can read

• Emission-related trouble codes (for example P0420 or P0171) and the check engine light status.
• Readiness monitors, which show whether the car's emission self tests have finished since the last code clear.
• Freeze frame data saved when a fault was detected, plus live engine data such as RPM, coolant temperature and fuel trims.

What generic OBD2 can't read

• Generic OBD2 is built around emission-related systems. Codes and data from modules such as ABS, airbags, body electronics or comfort features are not part of the generic standard and usually need manufacturer-specific access.
• A trouble code tells you which self test failed. It does not on its own tell you which part to replace.

Using OBD Master Pro on a Volkswagen

OBD Master Pro works with standard ELM327 and ELM329 class adapters over Bluetooth Classic, Bluetooth LE, Wi-Fi or USB OTG, and supports CAN, ISO 9141-2, KWP2000, J1850 and J1939. It includes a generic OBD2 / EOBD profile for any compliant car plus brand profiles. For VAG brands (VW, Audi, Skoda, Seat, Cupra) the app also offers coding where supported, including long coding and adaptations on platforms such as MQB, PQ26 and MLB-Evo. Results depend on your car, its modules and your adapter.

Tips

• Turn the ignition on (or start the engine if the app asks) before connecting.
• Read and write down all codes and the freeze frame before clearing anything.
• Clearing codes also resets the readiness monitors. Drive normally for about a week before an emissions inspection so they can complete.
• Most VW cars in Europe are covered by the EOBD dates above, so use the generic OBD2 / EOBD profile if you are unsure which brand profile fits.
• Unplug the adapter when you are done rather than leaving it connected while driving.

Keep reading

All OBD2 guides · OBD2 by car brand · OBD2 trouble code guides