Auto enthusiasts and technicians alike will mention plenty of abbreviations in their conversations, with OBD being one of the more common ones. But what does OBD stand for, and why does it matter to anyone?

OBD refers to on-board diagnostics, consisting of a long list of data collected by various sensors all over your car. You can retrieve that data by plugging a scanner into your car's OBD port, located under the dashboard on the driver's side. That data will include fault codes, emissions information, and even driver behaviour, to name a few.

This article will dive deep into what OBD is, how it works, and how you can benefit from it.

Let’s get started.

What Is OBD, and How Does It Work?

On-board diagnostics, or OBD, is a car computer system that identifies problems in the vehicle’s various systems. The system then communicates those problems by providing you with the relevant error code.

You’re already familiar with the warning lights that light up on your instrument panel whenever something goes wrong. You can think of those warning lights as the older and much more basic version of OBD. 

OBD does the same thing, but it doesn’t just illuminate a symbol that could mean a dozen different things (e.g. the Check Engine light). Instead, it provides you with much more specific information about what’s wrong, thanks to the input from all sensors installed throughout your vehicle.

What Information Can OBD Provide You?

On-board diagnostics can tell you specific faults or errors through fault codes. It makes troubleshooting a problem so much easier and on-point.

The OBD information can also go into great detail. For example, the OBD provides data that allows you to figure out the driver’s behaviour on the road (like their driving speed and how high they push the engine’s RPMs), the vehicle’s emissions, its various temperatures, and so much more.

In a way, an OBD is to a car, as a black box is to an airplane, recording pretty much everything and making it available for review whenever necessary. 

How to Use OBD

So, how do you connect to or access OBD and learn what it has to tell you? Most cars these days have an OBD port hidden somewhere under the driver’s side of the dashboard. This port allows you to connect an OBD reader or scanner to the car and retrieve the diagnostics information you need.

Your mechanic will most likely have an OBD reader or scanner because it speeds up their job if they know right away where to look. It’s not only the pro who will find this device useful. Regular people like you and me can also benefit from an OBD scanner and, maybe, reduce our garage fails significantly. 

You probably won’t find an OBD port on very old cars. That’s because it was only in recent decades that countries worldwide started making OBD ports compulsory for all vehicles.

In Australia, for example, all vehicles made after 2006 were required to be OBD 2 compliant (a newer OBD standard).

Understanding the Different OBD Standards

Not all OBDs are made the same. When it was still new decades ago, most manufacturers had their version of OBD for their vehicles. Unfortunately, this was an inefficient mess because it meant that the OBD fault codes would be very different depending on what car make and model you might have been driving then.

This period was the time of OBD 1, basically the first generation of OBD. Mechanics and technicians had a tough time with these systems because they had to work on so many different cars, and there was no standardisation when it came to OBD.

Here, it’s essential to understand that there technically wasn’t/isn’t an ‘OBD 1’ standard. Why? All auto manufacturers had their own OBD coding system, and each automaker’s OBD was different from the rest. So when people say ‘OBD 1’, they're collectively referring to all the different OBD systems that existed before they were standardised into OBD 2.

OBD II or OBD 2

Around the mid-1990s in the United States, OBD II (or OBD 2) was developed. This version of OBD was the standard by which all car manufacturers could design their vehicles' on-board diagnostics. Fast forward by a few years, and OBD 2 became the compulsory standard to follow. It didn't take long before the standard was adopted by most American states and became a requirement nationwide.

Afterwards, the OBD 2 standard became the norm worldwide, and any vehicle produced for the Australian market post-2006 was required to follow this standard.

EOBD

As with most industrial standards, the Europeans had their version as well. That’s where EOBD comes into play. Care to guess what it stands for? That’s right! EOBD stands for European On-Board Diagnostics.

All petrol vehicles made post-2001 (and diesel post-2003) were required to follow the EOBD standard.

Then, there’s the EOBD2 standard as well. Don’t let the number 2 fool you. It’s not a newer or better version of EOBD. Instead, it’s an EOBD standard with unique features that cater to specific auto manufacturers.

OBD 1, OBD 2 or EOBD – Figuring Out What Your Car Uses

With OBD 1, OBD 2, and EOBD, how can you figure out which OBD standard your car uses? Thankfully, there are several ways to do this.

Check the Car (or the Manual)

Typically, there will be an indication somewhere on your car about what OBD standard it adheres to. Check for a sticker under the hood, or whip out the user manual and see what it has to say on the matter.

Alternatively, you could also call up the manufacturer’s Customer Support hotline and ask them as well.

Check the Year of Manufacture

Another way would be to do some very light detective work. First, identify your vehicle’s year of manufacture. Then, do a quick online search to figure out what OBD standard your country mandates for all vehicles of that year.

For example, in Australia, you can bet that any car made after 2006 uses OBD 2.

Check Online

Last but not least, you could Google it. This method would likely be the quickest way to get answers. There will be car websites sharing this information, or you’ll stumble on a forum where someone else with the same car as you has asked the same question about their car’s OBD standard.

Can You Use OBD 2 Scanners on OBD 1 Cars and Vice Versa?

Naturally, you might be wondering if an OBD 2 scanner is backwards-compatible with OBD 1. The answer is NO. You can’t use an OBD II scanner on an OBD 1 vehicle.

Remember: There technically isn’t an ‘OBD 1’, as auto manufacturers had OBD standards unique to their lineup of cars. So, OBD 1 is just an umbrella term that refers to anything before OBD 2.

There is a silver lining, however. For example, let’s say you’re a mechanic who needs to buy an OBD 1 scanner. Does that mean you will need a dozen different scanners to use on different types of cars? No, you don’t. 

Even though OBD 1 isn’t standardised, you can find OBD 1 scanners compatible with multiple car brands. So all you’d have to do is navigate the device’s menu and select the car brand and model that you want to use it with.

Watch out for More OBD Topics

Did you find this topic interesting? I hope you did because we’re not stopping here. Watch out for future articles under this blog category. We’re planning on writing more articles explaining different codes, what they mean, and how to fix errors.