What is an OBD2 Port And How to Locate It?

What is an OBD2 Port And How to Locate It?
All vehicles sold in the US after 1996 (and after 2001 in Europe) will have an OBD2 (Onboard Diagnostics 2) port. It's also called an OBD-II port and can be used to connect dedicated devices to retrieve data from the onboard computer. In many countries, the OBD2 port is a mandatory part of any car or truck, so it’s unlikely that there would be a modern non-EV car without one installed.
Onboard diagnostics themselves track a wide variety of vehicle-related data such as emissions, mileage, and many others. They also collect various wear-and-tear signals, which are outputted as an error code if a particular part has malfunctioned.
With OBD2 scanner, technicians and car enthusiasts can retrieve all the monitoring data and check diagnostic trouble codes. Some more advanced OBD2 devices can also retrieve manufacturer-specific diagnostic trouble codes, which are usually more descriptive and precise, and can provide more features than a regular OBD2 protocol such as various quality-of-life additions.

Evolution of OBD systems

As the name suggests, OBD2 is the second iteration of the onboard diagnostic system with the first being standardized in the late 1980s. Onboard diagnostics, however, have existed since the 1960s, but they weren’t standardized.
Vehicle manufacturers would each have their own system and protocols, which led to unnecessary complications when performing diagnostics and repairs. Collaboration between vehicle manufacturers and The Society of Automotive Engineers eventually led to the OBD1 system.
OBD1 had a fair share of its own issues. For example, there were less than a hundred trouble codes for all car models, most of which only directly dealt with emissions and the transmission. Additionally, the error codes weren’t standardized, so they usually differed between manufacturers.
Additionally, most of the other parts of the vehicle such as the ABS would require a completely different scan tool and also required an understanding of the preferred resistance and voltage values. While the first standardized OBD systems were beneficial, they were much too complicated for regular car owners.

The switch to OBD2

Developed just about a decade later, the OBD2 was a massive upgrade in terms of ease of use and vehicle data extraction capabilities. A major improvement, for example, was the connection of both the powertrain and emissions systems to the onboard diagnostics – and this is how OBD2 diagnostics developed.
With OBD2, a proper scan tool (or OBD reader as they’re often called) could now collect diagnostic data from both systems while also having a much wider range of trouble codes and OBD II protocols.
Additionally, standardized protocols are now in use for OBD2 ports. You’ll notice that not all pins are active in a port as some of them represent different communication protocols, which are used to retrieve the information. Previously, many different protocols such as the Keyword protocol or ISO 9141-2 were used.
In the 2000s, however, the Controller Area Network (CAN) protocol gained popularity and, by 2008, almost all vehicles integrated CAN due to regulatory requirements. Support for CAN can be verified by finding pins at the 6th and 14th slots.
Support for CAN is also highly useful for anyone using OBDeleven solutions. Our tools are designed to fully support vehicles operating in that protocol, except for the VAG group for which we have support for older OBD2 protocols as well. So, the pin placements, which may seem random at first, can tell you the communication protocol and which OBD devices are supported. 
Since the implementation of OBD2, the development of OBD reader tools also progressed quickly. Today, there are plenty of OBD reader tools that are perfectly usable by nearly anyone, regardless of their experience.
Connection to the OBD port is much simpler than before. Some devices also have Bluetooth connectivity, allowing users to view real-time data on their phones.

Locating the OBD2 port

While the OBD-II port location isn’t perfectly standardized, there are some common places where they are implemented. Here are some of the common locations for the OBD port:
  • Beneath the steering column. Depending on the car model, the OBD port may be to the left, in the middle, or to the right of the underside of the steering wheel.
  • To the left or right of the car’s dashboard. You’ll usually find it closer to the dashboard, a bit further away from the rest of the wheel.
  • Between the transmission and cup holder. Usually located near the bottom of the transmission or cup holder.
  • Near the music or navigation system. Sometimes, the OBD port may be placed somewhere next to the music or navigation system.
  • Beneath the glove compartment. In some cases, the port may be placed on the passenger’s side, placed beneath the glove compartment.
While even more locations are possible, the ones outlined above exhaust all of the common locations for the OBD port. If you can’t find it, it would be best to read the manufacturer’s guide as it will always have all of the interior outlined.

OBD compatibility

Even if all modern vehicles have an OBD2 port, different OBD readers will provide different capabilities. All OBD reader devices will be able to read the basic, standardized codes such as the ones associated with the infamous check engine light.
A more advanced OBD reader, however, will be able to retrieve manufacturer-specific codes. These capabilities are usually acquired through licensing agreements with manufacturers. While these are expensive to procure, the fault codes make it easier to diagnose specific issues, such as the check engine light.
For example, our OBDeleven devices can retrieve basic fault codes from all vehicles with the CAN bus protocol and manufacturer-specific ones from VAG, BMW, and Toyota Group cars. While these are permanent fixtures in our feature set, we are continuing to add more compatibility as we go.
Finally, as mentioned above, some OBD reader tools, including our own, will have Bluetooth connectivity capabilities. These make it a lot easier for users to continually monitor their car’s performance while being able to receive notifications in real-time.
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To Sum Up

The OBD port is an essential component of every car sold in the US (since 1996) and Europe (since 2001). Found at the front of the interior such as the car’s dashboard, it provides users with the ability to plug in a scan tool or OBD reader to retrieve information from the car’s onboard computer.
A more advanced OBD reader or scan tool is capable of retrieving manufacturer-specific codes, which make it easier to diagnose issues. Car enthusiasts may also use the same tools to monitor performance and perfect preventative maintenance.
Disclaimer: Advice, how-to guides, and car care tips on our blog are intended as helpful resources for general maintenance and repairs. While we strive for accuracy, the information is provided to the best of our knowledge and should be used at your own discretion and risk.

Always refer to your vehicle's owner's manual or consult a certified mechanic for specific repair details and safety procedures.