How Does An Auto Code Reader Work?


Apr 26th, 2021

How Does An Auto Code Reader Work?

Cars are becoming more modern and high-tech except for the warning lights on the dashboard—they seem stuck in the past! Even when something like the Check Engine light comes on, it'll take a lot of digging before you figure out the cause behind it. Wouldn't it be nice if there was a car diagnostic tool that could help you narrow down the problem even more?

Well, there is such a tool. It’s called a diagnostic car code reader, and it plugs right into your car’s computer. This tool is often referred to as an OBD scanner because it plugs into the onboard diagnostics (OBD) system to tell you what’s wrong with your car.

In this article, we’re going to explore everything you need to know about an auto code reader. Plus, we’ll even discuss how it is or isn’t different from an auto code scanner.

Let’s get started.

What Is an Auto Code Reader?         

An auto code reader is just as the name suggests: it’s a device that reads the error codes that your car’s computer displays. These codes correspond to specific problems that your vehicle might be having, giving you a much clearer idea of what might be wrong with your car.

Think of it this way: the warning lights on your dashboard point towards a broad problem, such as an engine issue (the Check Engine Light) or one with your brakes (the ABS warning light). Still, the list of triggers for each of those lights can be quite long.

With an auto error code, you’ll be able to pinpoint the problem much more accurately. That will save you and your mechanic a lot of time troubleshooting the root problem and resolving it quickly.

How Does a Diagnostic Car Code Reader Work?

Many car brands and models these days come with an onboard diagnostics (OBD) port. You’ll often find these somewhere under the driver’s side of the dashboard. It’s not that hard to spot; if it looks like a port that you might find on a computer, that’s probably it.

Here’s the thing: the OBD ports are standardised. So if your car has one, you can rest assured that any diagnostic car code reader on the market will be able to fit into it.

When you plug the auto code reader in, it’ll communicate with your car’s computer to see if it’s reporting any error codes. Those codes will appear on the code reader’s screen, and some models might even display a short explanation of what the codes mean.

It’s essential to manage your expectations when it comes to these codes. Yes, they’re much more specific than the warning lights on your dashboard. However, you’ll still need to put in some elbow grease to figure out the root of the problem and fix it.

What Does a Diagnostic Car Code Look Like?

So, what kind of code will you see on your auto code reader? Typically, the format of an auto error code is an alphabet followed by four digits (e.g. X1234). As mentioned before, some readers might also explain to you what those codes mean. If not, you’ll need to look it up in the user manual or online.

Again, these codes tend to be universal, so you won’t have a problem finding out what the codes mean.

Is a Car Code Reader the Same as a Code Scanner?

Technically, there is a difference between a car code reader and a code scanner. A car code reader is just that, a reader. It’s a simple and straightforward tool that plugs into your car’s OBD port, reads the error code, and tells you what it is. End of story.

A code scanner (keyword being ‘scanner’), on the other hand, is a much more versatile tool. Besides reading the code, some might even allow you to clear that code from the OBD (basically ‘tell’ the car that the problem has been resolved). On top of that, some code scanners enable you to run tests and provide you with plenty of information from a built-in database.

So, in short, a reader reads the code and tells you what it is. A code scanner gives you many more options on what to do with those codes.

What Are the Benefits of an Auto Code Reader?

Having a diagnostic car code reader is indispensable in this day and age. By having the ability to see a car’s error code, mechanics and auto technicians essentially have a way of ‘talking’ directly to the vehicle to identify what problems it might have.

In doing so, it'll save them countless hours and effort of tinkering. Instead, they'll be able to start implementing a fix much sooner for their benefit and that of the customer.

Is It Worth Buying an Auto Code Reader?

At this point, it should be pretty clear that a mechanic or auto technician must have an auto code reader to make their job easier. That’s a given. But are there any benefits for you, the everyday car owner and driver, buying an auto code reader of your own?

Yes, there are!

Benefits of Owning an Auto Card Reader

  1. Owning an auto code reader is an excellent way to understand your car better. With better understanding comes a better appreciation for the vehicle that you've invested so much money in.
  2. It’s also a good way of checking on your mechanic. Of course, mechanics have plenty more knowledge and experience than you or I might have. Still, having a general idea of your car’s problems before driving to your workshop could make the process much easier.
  3. Lastly, having a reader or auto code scanner could also save you a trip to the mechanic. You see, by diagnosing the car at home and figuring out what the problem is, you might find that it’s a small matter that only needs a DIY fix.

Who knows? Rather than take it to a mechanic, you might be able to solve the problems right in your garage.

Keep Yourself Updated!

To learn more about tools like an auto code reader, OBD scanner and many more, check out the blog over at You’ll find useful updates daily explaining all sorts of car-related topics. It’s also the best place to source auto parts, locate Aussie wreckers, sell a car or find one to buy! Find us here!

By Ray Hasbollah