OBD1 Vs OBD2: What’s The Difference? (Full comparison)


The history of Onboard Diagnostic is very interesting. The OBD evolution took too long. If you want a full comparison between OBD1 Vs OBD2, then this guide is for you.

If you’re reading about OBD-I Vs OBD-II, it means you already have basic knowledge of it.

If you don’t know anything about the onboard diagnostic systems, don’t worry, we’ll discuss everything from the basics.


What is OBD?

OBD is the short form of Onboard diagnostic. It’s a combination of electronic systems and sensors that keep track and regulate your vehicle’s performance.

A computer installed in your car and truck regulates the fuel injector and a lot of other functions with the help of various sensors. This computer is known as Engine Control Unit or Electronic Control Unit (ECU).

It’s a technical definition, and don’t stress if you don’t understand it. Let me explain in easy language.

Have you ever visited a mechanic shop to repair your car? Or did you notice many lights and indicators on your vehicle’s dashboard?

If yes, then you have probably seen a valve-like indicator on your car’s dashboard. That is Check Engine or MIL (malfunction indicator lamp).

Check Engine Light
MIL or Check Engine light

There are 16 sensors installed in your car, and whenever any sensor detects some issue, it sends the signal to ECU (a computer installed in your car).

Your car ECU detects the issue and converts those signals to digital form, and turns ON the MIL (malfunction indicator lamp). ECU will show an error code when you plugin an OBD2 scanner.

Why is an OBD System Needed?

OBD2 Plugged In

Due to the increase in the popularity of automobiles, few countries implemented some norms to regulate pollution. United States of America was the first country that implements the OBD system.

With the help of the OBD system, car owners can understand that something is wrong with their cars, and they can go for repair.

Also, due to this, pollution from the exhaust can be controlled. That’s why the State of California made it mandatory for all car manufacturers to implement the OBD2 system after 1996.

Who Introduced OBD System? (History Of OBD)

In 1968, Volkswagon introduced the first OBD system in their cars. It was made to detect the problems that occur in cars easily.

Although it was much more complicated but a great invention. After ten years, Datsun introduced a simpler OBD system with limited capabilities.

In 1979, the Society of Automotive Engineers (SAE) recommended a standardized connector and test signals.

It took almost ten years when standardization of onboard diagnostics came in the late 1980s, as per SAE recommendations. This standardized format was known as OBD-I.

After a few years, many modifications were done, and a new set of standardized connectors and DTCs (Diagnostic Trouble Code) was implemented as per SAE recommendation. It was termed as OBD-II system.

In 1994, the state of California mandated all car manufacturers to implement an OBD-II system for all vehicles sold after 1996.

After 1996, the OBD-II system became mandatory for all vehicles manufactured in the United States.

In 2001, the European Union also mandated all gasoline-driven cars implement an OBD system called EOBD (European OBD) system.

In 2008, all vehicles in the USA were required to implement OBDII through a Controller Area Network as specified by ISO15765-4.

OBD1 Vs OBD2 (Comparison)

OBD1 vs OBD2 Port
OBD1 vs OBD2 Port

Now you know the history and importance of the Onboard diagnostic system. Let’s compare OBD2 vs OBD1 and find out the differences. Also, find out what OBD is in your car.

It was complicated to use.It’s easy to use.
No standardized connector was used.It has a standardized connector as per SAE recommendations.
It has limited features to detect errors and monitor performance.It has more features that allow to detect errors and improve engine performance.
There was no standardized set of trouble codes.The OBD II has a standardized set of diagnostic trouble codes as per ISO 15765-4.
No programing features for ECUs.Certified mechanics can program ECUs.
It doesn’t have a wireless connectivity feature.OBD2 scanner can connect via Bluetooth and WiFi.


I tried my best to explain the OBD system in easy language. Also, I explained the history and modification of OBD. I hope you found my OBD1 Vs OBD2 comparison useful.

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