Most cars on the road will have an OBD system installed. OBD basically stands for On-Board Diagnostics, and it refers to a car’s in-built computer system.
Why is this system important? It can inform you of what’s wrong with your car so that you can do any necessary repairs and keep your car running smoothly.
But, OBD has two systems – OBD1 and OBD2, with OBD1 being the first system that was installed in cars in the ‘90s.
Let’s explore what OBD1 means and if your car could have this system installed, as well as how to access it with the use of an OBD scanner.
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How Does OBD Actually work?

We know that OBD is a system in cars, but how does it work? An OBD system will contain components such as sensors, a central system, and a connection point and indicators.
These parts all work together to allow for a vehicle-monitoring process to start. Let’s take a look at the OBD components in greater detail.
Electronic Control Unit (ECU)
This is the main part of the OBD system. It works by gathering data from sensors that are located all over the vehicle. The ECU will use this data to regulate the parts of the vehicle, such as its fuel injection.
It also monitors the car via these sensors for any problems that crop up.
Sensors
There are a variety of sensors placed throughout cars. You can find them all over the engine and chassis.
The sensors send codes to the car’s ECU so that the parameters and source of the problem can be recorded. These are interpreted by the ECU.
Diagnostic Trouble Code
The sensor will send lots of information to the car’s ECU. If it finds that some of the readings it’s receiving are not within a normal range, then this error code will be saved by the ECU as a Diagnostic Trouble Code (DTC).
How this code appears is in the form of numbers and letters which can give you information about the type of problem and where it’s located in the vehicle.
These codes can be standardized for all vehicles, or they can be specific to the car manufacturers.
After saving the DTC, the ECU will send the signal to your car’s warning lights so that you can be aware that there’s a problem that requires your attention.
Malfunction Indicator Lights
We mentioned that the ECU will send the signal of the error to the car’s warning lights. These lights are known as Malfunction Indicator Lights (MILs).
If the light remains on and doesn’t go away, then the problem is probably not a serious one. If, on the other hand, the light flashes then it is more serious and whatever’s faulty needs to be repaired as soon as possible.
Diagnostic Link Connector (DLC)
Now, how does the car computer’s information get interpreted by you? That’s where the Diagnostic Link Connector comes into play. This is basically where you’ll be able to access the information from your car.
Cars with OBD will usually have their DLC in the OBD port that’s in the vehicle – this is usually underneath the dashboard on the driver’s side.
OBD1 History: How Did It Come About?

OBD has had a rich history that spans decades. Before OBD1 became a system installed in vehicles on the road, there was what was known as an Assembly Line Diagnostic Link (ALDL). This was introduced by General Motors in 1980.
How it worked was that it flashed the “check engine” light in vehicles.
When the car’s key was in the ignition and the engine was off, the light would flash and you’d have to count the number of blinks as well as how long each one would last before consulting a diagnostics chart so you could identify a problem in the vehicle.
Based on this, it’s clear to see that OBD car systems are not that recent and started many decades ago.
But, it was only in 1982 that OBD systems reached an important milestone: the California Air Resources Board (CARB) was trying to come up with regulations for vehicles sold in the state to have on-board diagnostic systems.
These would be used to detect any failures with the emissions systems in the cars to prevent high emissions from polluting the air. The first onboard diagnostic system was really simple.
It could only monitor a few car components, such as the fuel delivery system, engine control module, and oxygen sensor. In 1986, CARB insisted that all cars sold in the state would have this OBD system installed.
While this was useful, OBD1 was very limited. It was restricted for use on one type of vehicle, so you would need different adapters in order to gain information from the system on multiple cars. Here were some of its other problems:
- Some of the systems that were in place in vehicles were only capable of being scanned by professional mechanics who had specialized tools, so OBD1 wasn’t really something that car owners could do for themselves in order to maintain the correct functioning of their cars.
- Another problem that was experienced with OBD1 was that it would only cause the “check engine” light to come on when the engine fault had already happened and there was no way of monitoring engine deterioration. Basically, the damage was done and now you had the problem on your hands to deal with.
- In addition to the above, OBD1 was unable to check for failures of the catalytic converter and evaporative emissions system.
- To make it even less user-friendly, this system had data link connectors (DLCs) that varied in shape from one manufacturer to the next, and sometimes even when it came to car models that were made by the same manufacturer. This is why by 1988, the Society of Automotive Engineers (SAE) suggested that connectors should be the same shape and have pins that worked in the same way in a move to standardize the system.
Other Reasons Why OBD1 Was Limited

While it was quite limited in what it could do, OBD1 is still present in older cars. If your car was made before 1996 it probably has OBD1 on board.
This means that if you want to gain data about the car from its computer system in order to diagnose what’s wrong with it, you will have to use an OBD1 scanner.
This is a tool you can purchase from various sites, such as Amazon, and you will attach it to your car’s OBD port, which is usually found in close proximity to the steering wheel column.
Although you can find car scanner tools that can work with OBD1 systems, they’re still quite limited in what they can achieve.
However, the diagnostic trouble codes (DTCs) of OBD1-compliant vehicles are usually discovered without mechanics having to make use of expensive scanning tools.
This is because of how different manufacturers will make use of their own diagnostic link connectors and definitions in order to be able to access the vehicle’s error codes.
The DTCs from these vehicles are often read via blinking patterns of the “check engine” light and “service engine soon” light.
You have to connect different pins of the diagnostic connector for the error light to blink a certain number of times, which corresponds to the error code. It definitely sounds a tad outdated and complicated!
What further complicates matters is that some OBD1 cars have DTCs that can be interpreted or read in different ways. The system is by no means universal!
For example, Cadillac fuel-injected cars have onboard diagnostics that provide sensor data and trouble codes but you have to hold down the “off” and “warmer” buttons for a few seconds to activate the diagnostic mode without having to use a scan tool.
By comparison, some Ford vehicles between 1989 and 1995 were installed with a live sensor data stream available. Generally, though, what all OBD1 cars have in common is that there are fewer DTCs than what you’ll find in OBD2 vehicles.
From the above it’s clear to see that OBD1 wasn’t – and isn’t – user-friendly. Since OBD1 had many problems, such as when it came to not giving mechanics a lot of information about vehicle issues, it was soon replaced by OBD2.
How OBD2 Became The New Diagnostic System Standard
In 1996, OBD2 systems replaced OBD1 on newer cars. If your car was made in that year or later, chances are high it will have OBD2 and that means you can use an OBD2 scanner on it to diagnose faults.
OBD2 was a game changer in vehicle diagnostics. It became standard on modern vehicles with a 16-pin data link connector to make it versatile for lots of vehicles.
This system is much more advanced than OBD1, which is why OBD1 got replaced by it.
What Can OBD2 Do?

OBD2 is much more powerful than OBD1. As examples of what OBD2 can achieve, let’s take a look at some of its features and advantages:
- It has double the number of oxygen sensors as OBD1-compliant cars.
- It has powertrain control modules that are more powerful than OBD1.
- The powertrain control module (PCM) can be reprogrammed, thanks to the development of the Electronically Erasable Programmable Read-Only Memory chips.
- It has a better evaporative emission control system.
- It has a higher amount of Exhaust Gas Recirculation (EGR) systems with an EGR valve that’s operated electronically.
- It makes use of sequential fuel injection instead of throttle body or multiport injection. In addition to that, it’s equipped with a manifold absolute pressure (MAP) and mass airflow (MAF) sensor to better monitor the car’s engine load as well as airflow.
As a car owner, the above features are beneficial to you because they make it possible for you to gain a variety of information about your vehicle from its computer that has gathered information from the vehicle’s sensors.
If your car is OBD2-compliant, and it probably is if it was made in or after 1996, you will be able to use OBD2 scanners on it to retrieve error codes from the car’s computer.
This goes a long way to help you better diagnose your car of problems, and it can save you money that you’d have to pay to a mechanic to have a look at your car.
Why You Should Make Use Of Your Car’s OBD2

You might think that you don’t need to access your car’s diagnostic information because it’s too complicated, but this is no longer the case.
OBD2 devices have made it much easier for anyone to be able to access their car’s data in order to monitor their cars for problems. Here are some benefits involved with using your car’s OBD2 system.
You’ll get quick results
You don’t have to wait a long time in order to get the information you need about your car, as your car’s problems can be detected and sent to you within minutes.
You just need to connect your scanning tool to the car’s OBD port.
You’ll get accurate data
The OBD system ensures accuracy because of how the information you want to gain is gathered via sensors.
However, it’s worth noting that OBD2 offers greater accuracy than OBD1 because it not only tells you what’s wrong in certain parts of your car but can help you zone into the exact location of the fault.
Some of these scanning tools even tell you what repairs need to be made and if you can wait or if you should go ahead and get them done immediately.
You gain other information about your car
It’s not just data from the car’s engine and other components that you’ll receive via a car scanning tool.
You can also gain information about your car’s emissions so that you can ensure your car passes the annual emissions test, as well as information pertaining to your driving habits.
For example, you could use OBD2 to learn how fast your car is traveling, to track your car’s revolutions per minute, to work out your fuel consumption, and to track your trip data.
This makes it highly versatile for car owners. In addition to the above, you can also gain your car’s Vehicle Identification Number (VIN) from an OBD scanner. This is vital to know because you’ll be able to learn about your car’s history.
What To Know About OBD2 Scanners

Based on what we’ve featured so far in this article, you might think that OBD2 scanners are all going to give you a comprehensive diagnostic tool for your car. But this is not the case.
There are some important things to bear in mind before you purchase an OBD2 scanner.
Although OBD2 scanning tools are generally better than OBD1 tools because they can give you more information about your car’s wellbeing, there are some OBD2 scanners that will be quite limited when it comes to the features they offer.
An example concerns the car’s ABS systems. If you need to check this system in your car, you will not be able to do so with the use of any OBD2 scanner on the market.
While most of them will have standard functions, some specialized error codes will not be provided. You will have to purchase an OBD2 scanner that specifically offers the features you want.
These scanners don’t all work on all OBD2-compliant vehicles.
While it might seem like you can just choose any OBD2 scanner for your car, you must always check that the scanner is compatible with your car’s make and model.
This will ensure that you can make use of all the features it has to offer.
How Do You Access Your OBD?

We’ve already explained where you can find your OBD port, but in some cars it’s a bit more difficult to locate.
This is because of how certain manufacturers will put the OBD port in an uncommon spot, so it’s good to grab a torchlight and search underneath the steering wheel on the driver’s side of the car.
You’ll probably see a protective cover under which is the OBD port. If you still can’t find it, consult the user manual.
Accessing your car’s information via this port requires a scanner, as we’ve already explained, but it’s worth noting that you can connect to your car’s OBD in a variety of ways.
If you have an older car that uses OBD1, you will have to access it via a cable because there are no other options available.
On the other hand, if you have an OBD2 vehicle, you can connect to the system in a variety of ways. There are some wired connections available, but you can also access it via Wi-Fi, Bluetooth, and apps.
This means that you can use your iPad, smartphone, or tablet to be able to access the information from your car.
Whether you’re a beginner or experienced with OBD systems, there’s a way for you to be able to access this valuable information to keep your car in good condition.
Is There Going To Be An OBD3?

There is the idea that OBD3 will replace OBD2.
This system is set to be much more technologically advanced, both in what it will be able to do as well as how it will make our roads safer because the car’s information will not be sent to you but also go to your insurance company and the authorities in some cases, such as if your car is unsafe.
People are saying that OBD3 could soon be integrated into modern vehicles, perhaps electric cars specifically. But we still don’t know when this will occur.
What is for sure is that OBD3 will take car diagnostics to a completely different realm. To find out more about what could happen and what OBD3 will possibly entail, read our article,” OBD3: Does It Exist?”
Did You Know There Was An OBD1.5?

Interestingly, there was an OBD1.5 system that was used as a hybrid system because it was a partial implementation of OBD2. This was used by General Motors on some vehicles from 1994 to 1996.
Some of the vehicles would have a few OBD2 error codes implemented in their systems, such as the 1994 Corvette.
This OBD1.5 system was actually installed in a variety of vehicles at the time, such as Saab vehicles, Buick Regal, Chevrolet Monte Carlo, Pontiac Sunfire, and others.
But, with OBD2 arriving, it was clear that there was a better way for modern cars to be monitored and diagnosed.
Related Questions
What types of OBD scanners are there?
You can find code readers, which are pretty basic, DIY scanners that have standard and more advanced features, and professional scanning devices.
Do you need a professional car scanning tool?

While these are available and will have advanced features, such as key programming and ECU coding, they are best used by professionals who know their way around cars and will be able to make use of the data.
What advanced features should you look for in a car scanning device?
It’s worth looking for features that give you data on your mileage, fuel consumption, oil changes, and misfire counts.
Ensure that your car’s ABS and transmission systems will be monitored by the scanning device.
Conclusion
You might’ve heard that your car has an OBD system installed, but what does this mean and how can you access it even if you’re not a professional mechanic?
In this guide to OBD1, we’ve looked at what the different OBD types are, how they came about, and why they’re valuable for monitoring and diagnosing your car.
We’ve also looked at OBD scanners and what these tools can do to help you stay on top of any problems your car might encounter.
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