What are OBD, OBD2, and EOBD?

Have you ever got surprised at the many things that are hidden under your vehicle’s dashboard?

You’ll find almost every onboard system of the car located there, and basically, it is the entry point to everything that makes the whole vehicle tick.

Today on this page, you will learn all about OBD, OBD2, and EOBD, and what can we do with them.

What is OBD?

OBD is short for “On-Board Diagnostics”.

It is a standardized system that allows a vehicle’s computer to interface with external electronic devices. The devices are popularly known as OBD scanners or OBD scan tools.

Where is the Connector?

The connector is required to be located within the passenger compartment of the car, within reach of the driver’s seat.

In some vehicles, it’s found below the gearbox, in others beside the steering wheel and others have it at the foot of the passenger seat.

Tools should not be required to reveal the connector, but it may have a removable cover over it.

Why We Need OBD?

OBD gives the vehicle the ability to do self-diagnosis and reporting.

It is the system that is made up of an Electronic Control Unit (ECU), sensors and actuators.

The ECU collects input from sensors (like oxygen sensors, mass airflow sensors, and voltage sensors) and then uses it to control actuators (like fuel injectors and hydraulic cylinders) to get the desired performance.

It was originally developed to primarily reduce emissions by monitoring the performance of an engine’s main components.

Additionally, it was meant to diagnose the electronic fuel injection system that was adopted by automakers on a large scale in the early 1980s.

What is OBD2?

OBD2 was first introduced in vehicles made in 1994. It became a mandatory requirement for all cars and light trucks made from 1996 onward.

All vehicles sold in the US since 1996 use the OBD2 standard. As such, they come with an OBD2 port – usually located just below the dashboard – where an OBD2 car diagnostic tool plugs.

This system features a set of standards that describe how a car diagnostic tool and ECU interchange digital information.

What is EOBD?

You need to know that the OBD is an American standard. So if you are in Europe then you would be dealing with the EOBD.

It’s basically the European version of OBD2.

This system applies to all gasoline and diesel vehicles sold in Europe since 2001 and 2003 respectively.

Every EOBD-compliant vehicle has a standard port like the OBD2 port where a car diagnostic tool plugs in. It too is a universal 16-pin port.

OBD1 vs. OBD2 vs. EOBD Chart
Introduction 1991 1996 2000
Nature Semi-automatic self-diagnostic system Fully automatic self-diagnostic system
Function Access ECU and diagnose sensors and actuators
Standardization Not standardized Standardized on all American vehicles made from 1996 Standardized on all European vehicles made from 2000
Application Californian standard Federal standard EU standard
Interface Manufacturer-specific Universal
What Can We Do With These OBD Systems?

Usually, the car itself will warn you in advance when there’s a malfunction through its OBD systems.

It does so using the Check Engine Light, otherwise known as the Malfunction Indicator Light (MIL).

Now when the light comes on, you can use a car diagnostic tool to access the ECU and check sensors and actuators for faults.

Then you can check their status and even repair those that are faulty using the information provided on the car diagnostic tool.

What Tools Can We Use?

Each modern vehicle basically features a fault code memory that can be accessed with a car diagnostic tool.

Additionally, EOBD provides a platform for retrieving uniform fault codes regardless of the make of the vehicle.

Car owners and mechanics can use the codes (and other diagnostic data) to do repairs and maintenance.

With a good tool, you will have unrestricted access to all the emission systems.

Some car diagnostic tools not only display DTCs but also interpret the codes, show live sensor data and provide repair recommendations.

Here Are Some of Our Recommendations
1. ANCEL AD310 OBD2 Scanner
ANCEL AD310 OBD2 Scanner
4.6 / 5

The classic design of the scanner will let you save time and money as it can fix the problem quickly.
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Features Pros Cons
Perfect for knowing the cause of engine light
Directly indicates the test results
Ability to support intermittent reading
Comes with free frame data viewing
Works with vehicle power
Quickly provides historic codes
Thick insulator cable for better flexibility
It takes time to get used to its interface
2. TOPDON AL500 OBD2 Scanner
TOPDON AL500 OBD2 Scanner
4.9 / 5

This can show code definitions along with on-board monitoring. You can even identify probing in relation to vehicle emissions and fuel efficiency.
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Features Pros Cons
Perfect for initiating EVAP system leakage test
Comes with universal compatibility
Allows initiating EVAP leak test of the vehicle
Provides information regarding fuel efficiency
3 LEDs can directly show the car’s status
Easy operation and very user-friendly
Records data for playback at any time
A LED light comes with the connector
Allows data view in graphic
Detailed DTC lookup database
The brand is new and not popular.
3. Autel AL319 OBD2 Scanner
Autel AL319 OBD2 Scanner
4.6 / 5

The scanner has an easy user interface making it great for beginners. You can get all the necessary information and take appropriate action.
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Features Pros Cons
Comes with a free lifetime update
Prevents emissions with the one-click key
Includes built-in speaker and LED indicator
Multilingual design for international use
Accurately locates the various malfunctions
Prevents extensive menus search with I/M readiness key
Retrieves both manufacturer and generic codes
No manual included.