OBD1 vs OBD2: The Key Differences

OBD1 vs OBD2: The Key Differences
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OBD scanners help people diagnose error codes from their cars. Without an OBD scanner, we would have a more challenging time figuring out what is wrong with our cars. Mechanics benefit most from these scanners to diagnose cars and make the necessary repairs. There are two main types of scanners currently on the market, the OBD1, and the OBD2 scanner.

This article will look at the differences between the two diagnostic scanners and answer whether OBD2 scanners can read codes from OBD1.


OBD stands for onboard diagnostics, which is a system that scans the entire vehicle using an onboard computer. The earliest OBD systems were used to turn on the car malfunction lights such as the dreaded engine light. Over the years, the technology has developed to include more standardized information on vehicles.

Can OBD2 Scanners Read OBD1 Codes?

OBD2 compatible cars use standardized protocols for communications while OBD1 cars use specific protocols for communication. This makes these two systems largely incompatible. The connectors, pins, bus communicators, and even error codes can vary greatly from one manufacturer to another.

The differences in these systems are also apparent in the kind of data it manages. As for OBD1, their systems can only record up to 300 data parameters compared to the over 15,000 possible parameters recorded by an OBD2 scanner. This means that the data that comes from an OBD1 scanner cannot be used in complex diagnostics or even for monitoring various gauges in real-time.

It is not possible for an OBD2 scanner to readily read codes from an OBD1 scanner because they use different technology. However, with the use of an emulator, it is possible to use an OBD2 scanner as a code reader for data from an OBD1 scanner. There are emulators in the market that can read data from over 700 cars.

Differences Between OBD1 and OBD2

The OBD2 scan tool is a more advanced technology when compared to the OBD1. The OBD2 has more and better-standardized vehicle protocols and a system that checks and validates the data. The OBD1 has to be corded at all times to work while the OBD2 can be connected wirelessly through Bluetooth or Wi-Fi.

The OBD2 has a lot more universal appeal because it is a lot more reliable thanks to its wider compatibility. This is why it is sometimes referred to as a full-feature scanner.

How Can You Tell the Difference Between OBD1 and OBD2?

The OBD1 and the OBD2 systems have differences in a few characteristics. Here are some of the ways in which OBD1 and OBD2 scanners differ:


The OBD1 can only support cars manufactured in or before 1995 alongside some models from the 1980s. The OBD2, on the other hand, supports all cars manufactured after 1996. This has led to some people referring to the scanner as the classic scanner.

Installation process

The OBD1 has a fairly simple installation process easily connecting to the console which also makes it rather easy to use. The OBD2 scanner on the other hand can connect wirelessly over Wi-Fi or Bluetooth. It also has some corded varieties for compatible vehicles.


OBD1 scanners are manufacturer-specific and can only work with the single brand they are compatible with. On the other hand, OBD2 scanners can work with multiple brands since their protocols and messages are a lot more standardized.


With an OBD1, the scan tool is able to check the sensors, high signs of resistance, open and shorts. All the values collected are sent to the Engine Control Module (ECM) for processing. The OBD2 on the other hand can perform all the functions of the OBD1 scan tool in addition to the ability to represent the data graphically. It can also perform customization, smog tests, and monitor performance level and battery use.

Output generation

An OBD1 tracks the energy and fuel used and compares it to the data in the output. An OBD2 on the other hand has improved signal protocols and messaging formats by involving other factors.


The accuracy of the OBD1 scan tool was poor, only showing CEL messages without any accompanying detailed codes. The accuracy in OBD2 scanners is much higher, showing messages with a code that can be used with a reference in order to help identify the nature of the problem.

Mechanic holding code reader to diagnose car engine problems

Explanations for the Key Differences

OBD1 Scanner

OBD1 is a diagnostic system that can only support cars made before 1996, having been introduced in 1991. The biggest downside of this technology is that it is manufacturer-specific. A scanner cannot work with two different brands of cars even if the cars have the same issues. For example, a scanner that works on a Toyota will not work on a Ford.

The OBD1 scan tool offers the most basic functionalities. It can check emission systems, has the ability to read and monitor the engine performance, and then proceed to produce trouble codes. It also has a built-in code reader to help solve any engine performance issues.

The information that the system can display is quite basic. It can alert that there is a problem but cannot help point out where the problem is. Its main benefit is that it can point out engine faults early, thus enhancing the car’s lifespan.

OBD2 Scanners

These scanners can support all models manufactured after 1996 including a select number of hybrids and even electric vehicles. Unlike the OBD1 scan tool, they not only offer the most basic features but also present an array of other advanced functions. Some of these functionalities include monitoring:

  • CEL, RPM, pressure, speed, coolant temp
  • The Air Fuel Ratio in the engine
  • The fuel pressure, smog testing, oxygen sensors, DPF temperature, and the coolant temperature

It can also measure battery performance, oil temperature, offers live readings, and overall engine performance.

OBD2 also sets itself apart from the OBD1 scan tool through its advanced set of functionalities. These include:

  • Performing online programming including ECU programming
  • Managing anti-lock brake system, key codes, various air bag problems, and even issue video relays
  • Handling misfires and ABS

The OBD2 is also a lot less obtuse compared to the OBD1 as it offers an array of customizations that can let you view the data graphically. On top of that, it can graphically guide the user to the source of the problem in the vehicle. This allows users to get more reliable repair services which enhance the longevity of the vehicle.

The diagnostic tool can also expose engine issues. Once identified, you can proceed to check the engine light and fix the problem. This is especially important in commercial vehicles like a light truck where a delay could cause losses.

At the end of the day, the OBD2 is simply the better option, though you should make sure it is compatible with your car. Although an OBD2 may have an entire array of features it would be useless if it isn’t compatible with your car. All you would get are diagnostic trouble codes that you would not understand.

What are the Correct Uses for the OBD1 and the OBD2 Scanners?

Why Use an OBD1 Scanner?

Even though OBD1 scanners are not supported by any car built after 1996, they can still be very useful. They can be very easy to use but they have to be corded to work while offering limited functionalities.

Many car owners prefer to use a scanner that acts as both an OBD1 and OBD2 scanner. These scanners can support all kinds of cars despite their date of construction while offering a mix of functionalities from the OBD1 and OBD2. Generally, the OBD1 can help solve minor problems but cannot offer advanced functions. Though some of the devices have in-built memory used to store some codes, these codes can often be notoriously difficult to understand.

Why Use an OBD2 Scanner?

This is the more preferred diagnostic scanner but it can only find use in cars built after 1996. For people looking to build their acumen at fixing vehicles, the OBD2 will be their best bet. They can solve all the basic problems while also having pretty advanced features.

Moreover, people who do not know much about cars would prefer the OBD2. Since it offers more specific and detailed information, it is easier for amateurs to interpret the diagnostics if they have basic car knowledge.

OBD2 scanners are relatively simple to use and can work wirelessly but there are options for using corded diagnostic tools. Today, a lot of OBD2 scanners have an app that can help interpret and display data concisely.

Among the advertised OBD2 scanner features is its code lookup functionality. Though this is handy, getting complete answers relies on the compatibility of your scanner with the vehicle. Therefore, you might end up looking at the owner’s manual to identify the issue. 
Some scanners feature a code translation function and simply basic solutions. This helps speed up the repair procedure. However, it relies on how updated the device is and the vehicle’s backlog on record from the scanner manufacturer.

Do You Need an OBD2 or OBD1 scanner?

Before investing in a scan tool, you should know the scan tool standard of your vehicle: OBD2 or OBD1.

As a measure to reduce vehicle emissions, California introduced the pioneer legal standard in 1981. The standard mandated every vehicle sold in California have a basic onboard diagnostic system. The standard became popularly known as OBD-I. However, the law failed to advocate for using a universal interface and testing protocol.

Before the OBD-I standard of California, most manufacturers were designing vehicles featuring onboard computer systems. They would then establish their proprietary requirement for ports, test signals, and diagnostic connectors. California Air Resources Board, in 1994, issued OBD-II specifications. These expanded on the earlier law by necessitating standardized data link connectors beginning with vehicle models of 1996.

The implication is that for 1996 vehicles or newer ones, your vehicle will require the ability to scan OBD2. Before that, vehicles would typically require OBD1 scanners. However, there are several 1995 exception models. It would be best if you appreciated that a specialized OBD1 scanner working with your 1994 Mustang would not work with a 1992 Corvette. Fortunately, the scan tools (single application) are usually affordable. Additionally, the scan tool might meet all your needs if you are a traditionalist tending to drive older vehicle models.

Most OBD2 scanners also feature adapters that let them work with the older vehicle models, though you will need to pay extra for them.

OBD2 Buying Guide

Your ideal OBD2 scanner will depend on the required vehicle information and the extent of your mechanical knowledge. If you want to make simple repairs or ensure your car passes the inspection test, an OBD2 scan tool could be a worthy investment. However, if you are an expert mechanic, you will need a more advanced tool.

Buy According to the Work

The best means of determining whether you need an OBD2 scan tool is considering the specific type of task at hand. If it is double-checking a mechanic’s assessment or establishing the reason for a check engine light, you will require something capable of pulling codes.

If you are a consistent worker on your vehicle, you might want to use a scan tool that is compatible with domestic and foreign cars. Such a tool will receive updates more frequently. With the ability to change vehicle settings and send commands, they will be in a better place working with tire pressure monitors and temperature sensors. Accessing readings like misfire information and ABS can aid in better diagnosis of the general health of your vehicle. Bear in mind that extra programming options and features imply a higher price.

Wireless Vs. Wired

You should consider Bluetooth connectivity when searching for the best OBD2 scan tool. Since you must remain physically close to your vehicle as you conduct a diagnostic with a cord, the popularity of wireless scanners is ever-increasing. This is mainly because of their data collection abilities and simplicity. All that is required is a Bluetooth-enabled smartphone and an appropriate scanner app, and you will be ready to review data from the phone directly.

The option can be amazing if you are interested in a ‘set it and forget it’ type of tool to collect data as you drive. Nonetheless, it will also free you as the user from having to check under your hood as you run a diagnostic. But some superior scanners feature internal batteries capable of lasting for hours, meaning the required amount of information dictates the ideal OBD2 scanner for the task.

Code Lookup

Among the advertised OBD2 scanner features are its code lookup functionality. Though this is handy, getting complete answers relies on the compatibility of your scanner with the vehicle. Therefore, you might look at the owner’s manual to identify the issue.

Some scanners feature a code translation function and simply basic solutions. This helps speed up the repair procedure. However, it relies on how updated the device is and the vehicle’s backlog on record from the scanner manufacturer.

In Conclusion

OBD1 systems are made from rudimentary technology that is now obsolete. It uses pins, connectors, and protocols that were not standardized. This led to a free-for-all, where each manufacturer would use their technology, setting themselves apart from the rest of the world.

Luckily, there are ways to have the older generation OBD1 scanners communicate their diagnostic trouble codes with the newer OBD2. Through an adapter, we can get codes from the OBD1 scanners and have them read and interpreted by the newer OBD2 machines. However, you may need to use the services of a professional tech to achieve this.


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