What You Need To Know About ELM 327

What You Need To Know About ELM 327

Since the 1980s when the on-board computer was introduced, DIY experts and mechanics have had a difficult time trying to work on their vehicles. However, since the introduction of the microcontroller ELM 327, this is gradually changing.

The period between the 1980s and somewhere in the mid-1990s was a challenge for professionals, DIY experts and mechanics because each vehicle manufacturer at the time had their own protocols and standards which made it hard to keep up with. A standard known as OBD-II was implemented by automotive makers to help change this.

However, the professional tools used for scanning were still very expensive.

Data readers and basic codes cost a fortune up until a few years ago. It was possible to use simpler tools for the purpose of clearing codes and reading. There was however a problem with doing this; these simple tools did not give any access to PIDs which are crucial in diagnosing driveability issues and other vehicle related issues.

It is the elm 327 that helped solve this problem. It is a small microcontroller that is programmed and it is very affordable compared to the previous alternatives.

This microcontroller has been a long awaited solution and it has made great improvements for mechanics, automotive professionals and DIY experts.

How Elm 327 Works

Elm 327 acts as the bridge that connects your on-board computer to your hand held device or PC. It is capable of creating communication with OBD-II system. One the communication has been created; it relays the data either through Bluetooth, WI-FI or USB. This depends on the implementation.

The microcontroller supports different ISO and SAE protocols. One way to tell a legitimate elm 327 from a fake is the fact that a legitimate microcontroller will be able to create a communication with any OBD-II car. There is a common misconception that this microcontroller’s command set is identical to the Hayes. This is not the case. The two are just similar but have some differences.

Elm 327 Uses

If you have an ELM 327, it is possible to use it for the purpose of diagnosing your vehicle. It can be a truck or small vehicle. You will however need to have some software and hardware to do the diagnosis. To use the ELM 327, you will need to connect it to a smartphone, PC, tablet or any other device.

This connection can be done through several means. These include:

  • USB connection (Wired) – This type of connection has a number of advantages. These include: compatibility, affordability and no incidences of drop connections.
  • WI-FI connection (Wireless) – This one is great because you get to enjoy more compatibility with a number of devices compared to what you would achieve with Bluetooth. This type of connection is however quite expensive.
  • Bluetooth connection – Bluetooth is advantageous because it is found in most devices and it is not expensive. However, you might not be able to use it on iPhones.

Anyone with an Android device or a PC can therefore use any of these connections. If you own an iPhone, using Bluetooth may not work great for you. You can however make use of the other types of connection. With ELM 327, you can view PIDs and access trouble codes.

These codes can also be cleared once you are done fixing your problems since the kind of communication created is bidirectional. However, the actions you are able to be perform are dictated by the type of software and ELM 327 you are working with. Other data and readiness monitors can however be viewed regardless of the software and ELM327 device you are using.

Pirates and Clones

Like many other devices in the market, the ELM 327 has a number of pirates and clones in the market. It is therefore advisable to be careful when looking to purchase this device. The worst thing about these clones is the fact that you might get some that work very well. They are however not able to match up to the original.

The reason why there are so many pirates and clones is the fact that Elm Electronics the company that manufactured the device did not copy protect their device.

If you do your research, you will notice there are manufacturers that even say that their products are better and they have a new version which has not even been created. It is therefore a good idea to try doing your research or ask for professional help if you do not know how to go about spotting a fake.

This will definitely save you a lot of time and money that would otherwise be spent looking for a new product one the knock-off does not perform as you expected it to.

Scanning Alternatives

There are different scanning alternatives that are all priced differently apart from elm 327. These work great for those who are looking for scanning tools that are stand alone. They include:

  • Code Readers (Simple): These ones can only be used for the purpose of reading and clearing codes.
  • Scan Tools (Dedicated): With these tools, you can be able to view PIDs and access codes. They are also great for troubleshooting.
  • OBD-I: These are excellent for vehicle build in the 60s. They sometimes work on specific car makes. However, it is possible to use it on different car makes if it is the type that comes with an adapter.

Elm 327 is the most effective in terms of price and being able to view PIDs and access codes. However, there are situations where you might not be able to use this microcontroller and will be forced to utilize any of the above options.

For instance, if you have a vehicle that was made before 1996, it might not be possible to use ELM 327. The three options work best for such vehicles and they are also quite effective. However, if you have a vehicle made after 1996, you should have no problem working with ELM 327.


In conclusion, elm 327 is an invention that for many mechanics, professionals, and DIY experts has been a life saver. It is a great device to help you troubleshoot problems in your vehicle to make sure it works well. It is effective, affordable and most importantly, can be used in most vehicles.

What You Need To Know About ELM 327
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